Author Archives: Swati

SHORT ANSWER TYPE QUESTION:

Q1.What is natural vegetation? Under what climatic conditions are tropical evergreen forests develop?

Answer

Natural vegetation refers to a plant community that has been left undisturbed over a long time, so as to allow its individual species to adjust themselves to climate and soil conditions as fully as possible.
Tropical evergreen forests develop in warm and humid areas with an annual precipitation of over 200 cm and mean annual temperature above 22°C.

Q2. What do you understand by social forestry?

Answer

Social forestry means the management and protection of forests and afforestation on barren lands with the purpose of helping in the environmental, social and rural development.

Q3. Define Biosphere reserves?

Answer

A Biosphere Reserve is a unique and representative ecosystem of terrestrial and coastal areas which are internationally recognised within the framework of UNESCO’s Man and Biosphere (MAB) Programme.

Q4. What is the difference between forest area and forest cover?

Answer

The forest area and forest cover are not the same.

• The forest area is the area notified and recorded as the forest land irrespective of the existence of trees, while the actual forest cover is the area occupied by forests with canopy.

• The forest area is based on the records of the State Revenue Department, while the forest cover is based on aerial photographs and satellite imageries.

• According to state records, the forest area covers 23.28 per cent of the total land area of the country while the actual forest cover in India is only 21.05 percent.

Q5.What steps have been taken up to conserve forests?

Answer

There are various steps taken based on the forest conservation policy. These are:

• Social forestry: It means the management and protection of forests and afforestation on barren lands with the purpose of helping in the environmental, social and rural development. The National Commission on Agriculture (1976) has classified social forestry into three categories. These are Urban forestry, Rural forestry and Farm forestry.

→ Urban forestry: It pertains to the raising and management of trees on public and privately owned lands in and around urban centres such as green belts, parks, roadside avenues, industrial and commercial green belts, etc.–

→ Rural forestry: It lays emphasis on promotion of agro-forestry and community-forestry.

→ Agro-forestry: It is the raising of trees and agriculture crops on the same land inclusive of the waste patches.

• Community forestry: It involves the raising of trees on public or community land such as the village pasture and temple land, roadside, canal bank, strips along railway lines, and schools etc.

• Farm forestry is a term applied to the process under which farmers grow trees for commercial and non-commercial purposes on their farm lands.

Q6.How can people’s participation be effective in conserving forests and wildlife?

Answer

The government can make policies on the conservation of forests and wildlife but it is on the people who take part in this and make them successful. It is mostly the local people who take part in the illegal activities by damaging the environment for their benefits knowingly or unknowingly. The government need the cooperation of common people for ensuring the protection against the deforestation, poaching, hunting etc. This can effective in many ways:

• Holding a regular meeting of local people and make them aware of the advantages of conservation of forests and wildlife.
→ The government officials can inform them about the various policies of the government about the conservation and how they can be part of it.

• Incentives for the good work: The government can provide the incentives to the local people for their good work in protecting the local trees or wildlife which will encourage others to do the same work. Gradually, it will spread to mass scale.

• Various NGOs can also help in doing this activity by providing the skills to the people in conserving forests and wildlife through their experts.

Long Answer Type Questions:

Q1.“Natural vegetation is an outcome of climate.” Substantiate the statement by taking example of Indian vegetation.
Answer:
India is a land of great variety of natural vegetation. Himalayan heights are marked with temperate vegetation; the Western Ghats and the Andaman Nicobar Islands have tropical rain forests.

• Tropical evergreen forests are found in warm and humid areas with an annual precipitation of over 200 cm and mean annual temperature above 22°C. In these forests, trees reach at great heights up to 60 m or above. The semi¬evergreen forests are found in the less rainy parts of these regions.
• Tropical deciduous forests are spread over regions which receive rainfall between 70-200 cm.
• The moist deciduous forests are more pronounced in the regions which record rainfall between 100-200 cm. Dry deciduous forest covers vast areas of the country, where rainfall ranges between 70-100 cm.
• Tropical thorn forests occur in the areas which receive rainfall less than 50 cm. In mountainous areas, the decrease in temperature with increasing altitude leads to a corresponding change in natural vegetation.
• The Himalayan ranges show a succession of vegetation from the tropical to the tundra, with change in the altitude. Deciduous forests are found in the foothills of the Himalayas. It is succeeded by the wet temperate type of forests between an altitude of 1,000-2,000 m. In the higher hill ranges of north-eastern India, hilly areas of West Bengal and Uttarakhand, evergreen broad leaf trees such as oak and chestnut are predominant. Between 1,500-1,750 m, pine forests are also well-developed in this zone, with Chir Pine as a very useful commercial tree.

Q2.Mention the reasons for the decline of wildlife in India?
Answer:
Important reasons for the decline of Wildlife in India are-

• Industrial and technological advancement brought about a rapid increase in the exploitation of forest resources.
• More and more lands were closed for agriculture, human settlement, roads, mining, resources, etc.
• Pressure on forests maintained due to looping for fodder and fuel, wood and removal of small timber by the local people.
• Grazing by domestic cattle caused an adverse effect on wildlife and its habitat.
• Hunting was taken up as a sport by the elite and hundreds of wild animals were killed in a single hunt. Now commercial poaching is rampant.
• Incidence of forest fire.

Q3.According to the statistics received from state records, there are differences in forest area and actual forest cover. Explain.
Answer:
According to state records, the forest area covers 23.28 percent of the total land area of the country. It is important to note that the forest area and the actual forest cover are not the same. The forest area is the area notified and recorded as the forest land irrespective of the existence of trees, while the actual forest cover is the area occupied by forests with canopy.
Forest area is based on the records of the State Revenue Department, while the actual forest cover is based on aerial photographs and satellite imageries.

According to India State of Forest Report 2011, the actual forest cover in India is only 21.05 percent. Of the forest cover, the share of dense and open forests is 12.29 and 8.75 percent respectively. Both forest area and forest cover vary from state to state. Lakshadweep has zero percent forest area; Andaman and Nicobar Islands have 86.93 percent. Most of the states with less than 10 percent of the forest area lie in the north and northwestern part of the country. These are Rajasthan, Gujarat, Punjab, Haryana and Delhi.

States with 10-20 percent forest area are Tamil Nadu and West Bengal. In Peninsular India, excluding Tamil Nadu, Dadra and Nagar Haveli and Goa, the area under forest cover is 20-30 percent. The northeastern states have more than 30 percent of the land under forest. Hilly topography and heavy rainfall are good for forest growth. There is a lot of variation in actual forest cover, which ranges from 9.56 percent in Jammu and Kashmir to 84.01 percent in Andaman and Nicobar Islands.

Q4.On the basis of actual forest cover, in how many categories have Indian states been divided?
Answer:
On the basis of the percentage of the actual forest cover, the states have been grouped into four regions:

• The region of high concentration > 40: It includes Andaman and Nicobar islands, Mizoram, Nagaland, Arunachal Pradesh which have 80% of their total area under forests. Manipur, Tripura, Meghalaya, Sikkim and Dadar and Haveli have forest cover between 40-80%.
• The region of medium concentration 20-40: It includes Madhya Pradesh, Odisha, Goa, Kerala, Assam and Himachal Pradesh. In Goa, actual forest cover is 33.27% which is highest in this range. Thereafter, comes Assam and Orissa. In other states 30% of their area is covered with forests.
• The region of low concentration 10-20: It includes states of Maharashtra, Andhra Pradesh, Karnataka, Tamil Nadu, Bihar and Uttar Pradesh.
• The region of very low concentration < 10: It includes states of Rajasthan, Punjab, Haryana, and Gujarat. It also includes union territories of Delhi and Chandigarh. It also includes West Bengal.

Q5.Explain in short about four important Biospheres of India.
Answer:
Four Biosphere Reserves have been recognised by the UNESCO on World Network of Biosphere Reserves. These are as follows:

1. Nilgiri Biosphere Reserve: The Nilgiri Biosphere Reserve (NBR) is the first of the fourteen biosphere reserves of
India. It was established in September 1986. It embraces the sanctuary complex of Wyanad, Nagarhole, Bandipur and Mudumalai, the entire forested hill slopes of Nilambur, the Upper Nilgiri plateau, Silent Valley and the Siruvani hills. The total area of the biosphere reserve is around 5,520 sq. km. The largest south Indian population of elephant, tiger, gaur, sambar and chital as well as a good number of endemic and endangered plants are also found in this reserve. The topography of the NBR is extremely varied, ranging from an altitude of250 m to 2,650 m. About 80 percent of the flowering plants reported from the Western Ghats occur in the Nilgiri Biosphere Reserve.

2. Nanda Devi Biosphere Reserve: The Nanda Devi Biosphere Reserve is situated in Uttarakhand. It includes parts of Chamoli, Almora, Pithoragarh and Ba’geshwar districts. The major forest types of the reserve are temperate. A few important species are silver weed and orchids like latifolie and rhododendron. The biosphere reserve has a rich fauna like the snow leopard, black bear, brown bear, musk deer, snow- cock, golden eagle and black eagle.

3. Sunderbans Biosphere Reserve: It is located in the swampy delta of the river Ganga in West Bengal. It extends over a vast area of 9,630 sq. km and consists of mangrove forests, swamps and forested islands. Sunderbans is the home of nearly 200 Royal Bengal tigers. More than 170 birds species are known to inhabit these mangrove forests. In the Sunderbans, the mangrove forests are characterised by Heritiera fomes, a species valued for its timber.

4. Gulf of Mannar Biosphere Reserve: The Gulf of Mannar Biosphere Reserve covers an area of 105,000 hectares on the south-east coast of India. It is one of the world’s richest regions from a marine biodiversity perspective. The biosphere reserve comprises 21 islands with estuaries, beaches, forests of the nearshore environment, sea grasses, coral reefs, salt marshes and mangroves.

SHORT ANSWER TYPE QUESTION:

Q1. What are the three important factors which influence the mechanism of Indian weather?
Answer
The three important factors which influence the mechanism of Indian weather are:• Distribution of air pressure and winds on the surface of the earth.
• Upper air circulation caused by factors controlling global weather and the inflow of different air masses and jet streams.
• Inflow of western cyclones generally known as disturbances during the winterseason and tropical depressions during the south-west monsoon period into India, creating weather conditions favourable to rainfall.

Q2. What is the Inter-Tropical Convergene Zone?
Answer
The Inter Tropical Convergence Zone (ITCZ) is a low pressure zone located at the equatorwhere trade winds converge, and so, it is a zone where air tends to ascend.
Q3. What is meant by ‘bursting of monsoon’? Name the place of India which gets the highest rainfall.
Answer
The sudden onset of the moisture-laden winds associated with violent thunder and lightening, is often termed as the “break” or “burst” of the monsoons.Mawsynram in Meghalaya is the place of India which gets the highest rainfall.
Q4. Define ‘climatic region’? What are the bases of Koeppen’s classification?
Answer
 A climatic region has a homogeneous climatic condition which is the result of a combination of factors. The bases of Koeppen’s classification are:• Temperature• Precipitation

Q5.Which type(s) of cyclones cause rainfall in north-western India during winter? Where do they originate?
Answer
Western cyclonic disturbances cause rainfall in north-western India during winter. They originate over the Mediterranean Sea.

Q6.Notwithstanding the broad climatic unity, the climate of India has many regional variations. Elaborate this statement giving suitable examples.
Answer
Due to the influence of monsoon, India as a whole has broad climatic unity. However, the climate of India has many regional variations expressed in the pattern of winds, temperature and rainfall, rhythm of seasons and the degree of wetness or dryness. There are various examples of this:
• Temperature: In the summer the mercury occasionally touches 55°C in the western Rajasthan, it drops down to as low as minus 45°C in winter around Leh. Churu in Rajasthan may record a temperature of 50°C or more on a June day while the temperature in Tawang (Arunachal Pradesh) is 19°C on the same day.
• Rainfall: Cherrapunji and Mawsynram in the Khasi Hills of Meghalaya receive rain fallover 1,080 cm in a year while Jaisalmer in Rajasthan rarely gets more than 9 cm of rainfall during the same period.
• Monsoon: The Ganga delta and the coastal plains of Orissa are hit by strong rain-bearing stormsal most every third or fifth day in July and August while the Coromandal coast, a thousand km to the south, goes generally dry during these months. 
Q7.How many distinct seasons are found in India as per the Indian Meteorological Department? Discuss the weather conditions associated with any one season in detail.
Answer
The meteorological department recognise the following four seasons :(i) the cold weather season(ii) the hot weather season(iii) the southwest monsoon season(iv) the retreating monsoon season.
• The cold weather season: The cold weather season sets in by mid-November in northern India. December and January are the coldest months in the northern plain. The mean daily temperature remains below 21°C over most parts of northern India. The night temperature may be quite low.The Peninsular region of India, however, does not have any well-defined cold weather season. There is hardly any seasonal change in the distribution pattern of the temperature in coastal areas because of moderating influence of the sea and the proximity to equator.
During the winters, the weather in India is pleasant. The pleasant weather conditions, however, at intervals, get disturbed by shallow cyclonic depressions originating over the east Mediterranean Sea and travelling eastwards.
Winter monsoons do not cause rainfall as they move from land to the sea. It is because they have little humidity and due to anti cyclonic circulation on land. So, most parts of India do not have
rainfall in the winter season. However, there are some exceptions, Rainfall occurs in northwestern India due to western disturbances. Central parts of India and northern parts of southern peninsula also get winter rainfall occasionally.

Long Answer Type Questions:

Q1.Explain the important features of Winter Season of India.
Answer:
By October, the rainy season comes to an end all over the country and the days become short and the night become long. The rays of the sun are not overhead. The air turns cooler in the plains marking the coming of the winter season.

The winter season lasts from November to February every year. In the Northern Plains, very cold wind blow making the winter months severe. December and January are the coldest months in the northern plain. The mean daily temperature remains below 21°C over most parts of northern India.

Most of the hilly areas receive heavy snowfall. January is the coldest month in the Northern Plains. The winter season in Peninsular India is mild as a result of the influence of the surrounding water bodies. The coromandel Coast receives heavy rainfall during this season.

The desert is cool during the day but cold at night. The air starts warming up in the month of March, and the weather is neither cold nor hot. This time of early summer is also called the spring season. Every part of our country regularly experiences this cycle of seasons.

Q2.According to Koeppen, in how many groups- can you classify the climate of India?
Answer:
Koeppen identified a close relationship between the distribution of vegetation and climate. He selected certain values of temperature and precipitation and related them to the distribution of vegetation and used these values for classifying the climates. Koeppen introduced the use of capital and small letters to designate climatic groups and types. Koeppen recognised five major climatic groups, four of them are based on temperature and one on precipitation.

• Tropical climates,
• Dry climates,
• Warm temperate climates,
• Cool temperate climates,
• Ice climates

Classification of Indian climatic regions: Amw – Monsoon with short dry season.
Areas: West coast of India south of Goa
As – Monsoon with dry summer
Areas: Coromandel coast of Tamil Nadu
Aw – Tropical savannah.
Areas: Most of the Peninsular plateaus, south of the Tropic of Cancer
Bwhw – Semi-arid steppe climate.
Areas: North-western Gujarat, some parts of western Rajasthan and Punjab
Bwhw – Hot desert. Areas: Extreme western Rajasthan
Cwg – Monsoon with dry winter.
Areas: Ganga plain, eastern Rajasthan, northern Madhya Pradesh, most of North-east India
Dfc – Cold humid winter with short summer.
Areas: Arunachal Pradesh
E – Polar type. Areas: Jammu and Kashmir, Himachal Pradesh and Uttarakhand.

Q3.Explain the spatial variation in the rainfall throughout the country.
Answer:
There is great variation in rainfall throughout the country.

• While Cherrapunji and Mawsynram in the Khasi Hills of Meghalaya receive rainfall over 1,080 cm in a year, Jaisalmer in Rajasthan rarely gets more than 9 cm of rainfall during the same period.
• Tura situated in the Garo Hills of Meghalaya may receive an amount of rainfall in a single day which is equal to 10 years of rainfall at Jaisalmer. While the annual precipitation is less than 10 cm in the north-west Himalayas and the western deserts, it exceeds 400 cm in Meghalaya.
• The highest rainfall occurs along the west coast, on the western Ghats as well as in the sub-Himalayan areas in the north-west and the hills of Meghalaya, rainfall exceeding 200 cm. In some parts of Khasi and Jaintia hills, the rainfall exceeds 1,000 cm. In the Brahmaputra valley and the adjoining hills, the rainfall is less than 200 cm.
• Rainfall between 100-200 cm is received in southern parts of Gujarat, east Tamil Nadu, North-eastern Peninsular covering Orissa, Jharkhand, Bihar, eastern Madhya Pradesh, Northern Ganga Plain along the sub-Himalayas and the Cachar valley and Manipur.
• Western Uttar Pradesh, Delhi, Haryana, Punjab, Jammu and Kashmir, eastern Rajasthan, Gujarat and Deccan Plateau receive rainfall between 50-100 cm.

Q4.Explain the spatial variation in temperature in India.
Answer:
India has hot monsoonal climate which is the prevalent climate in south and south-east Asia.

• While in the summer the mercury occasionally touches 55°C in the western Rajasthan, it drops down to as low as minus 45°C in winter around Leh.
• Churu in Rajasthan may record a temperature of 50°C or more on a June day while the mercury hardly touches 19°C in Tawang (Arunachal Pradesh) on the same day.
• On a December night, temperature in Drass (Jammu and Kashmir) may drop down to minus 45°C while Thiruvananthapuram or Chennai on the same night records 20°C or 22°C.
• In Kerala and in the Andaman Islands, the difference between day and night temperatures may be hardly seven or eight degree Celsius. But in the Thar desert, if the day temperature is around 50°C, at night, it may drop down considerably upto 15°-20°C.
• While snowfall occurs in the Himalayas, it only rains over the rest of the country. Similarly, variations are noticeable not only in the type of precipitation but also in its amount.

Q5.How economic life in India is affected by monsoon?
Answer:
Economic life of India is extremely affected by the monsoon.

• Monsoon is that axis around which revolves the entire agricultural cycle of India. Around 64 % people of India depend on agriculture for their livelihood and agriculture itself is based on south-west monsoon.
• Except Himalayas all the parts of the country have temperature above the threshold level to grow the crops or plants throughout the year.
• Regional variations in monsoon climate help in growing various types of crops.
• Variability of rainfall brings droughts or floods every year in some parts of the country.
• Agricultural property of India depends very much on timely and adequately distributed rainfall. If it fails, agriculture is adversely affected particularly in those regions where means of irrigation are not developed.
• Sudden monsoon burst creates problems of soil erosion over large areas in India.
• Winter rainfall by temperate cyclones in north India is highly beneficial for Rabi crops.
• Regional climatic variation in India is reflected in the vast variety of food, clothes and house types.

Q6.What is Global Warming? What are the effects of Global Warming?
Answer:
Due to global warming the polar ice caps and mountain glaciers would melt and the amount of water in the ocean would increase. It leads to rise in the sea level and melting of glaciers and sea-ice due to warming.

Effects:

• Sea level will rise 48 cm by the end of twenty first century.
• Increase the incidence of annual flooding.
• Insect-borne diseases like malaria, and leads to shift in climatic boundaries, making some regions wetter and other dries.
• Agricultural pattern would shift and human population as well as the ecosystem would experience change.
• The peninsular India would be submerged.
• Global warming refers to the increase in average ground temperatures refers to the increase in average ground temperatures on earth. These higher temperatures across the planet are caused by an intensification of the greenhouse effect.

Q7.What is Break in Monsoon? What are its causes? When is the monsoon expected to break in Kerala and reach the plains of Punjab?
Answer:
During the south-west monsoon period after having rains for a few days, if rain fails to occur for one or more weeks, it is known as break in the monsoon. These dry spells are quite common during the rainy season. These breaks in the different regions are due to different reasons:

• In northern India rains are likely to fail if the rain-bearing storms are not very frequent along the monsoon trough or the ITCZ over this region.
• Over the west coast the dry spells are associated with days when winds blow parallel to the coast.

Breaking of Monsoon:

• Breaking of the Monsoon in Kerala: Beginning of June.
• Reaching Punjab: First week of July.

SHORT ANSWER TYPE QUESTION:

Q1. State the differences between the following.
(i) River Basin and Watershed(ii) Dendritic and Trellis drainage pattern
(iii) Radial and Centripetal drainage pattern
(iv) Delta and Estuary
Answer
(i) River Basin and Watershed

River Basin	Watershed
The catchments of large rivers are called river basins.	The catchments of small rivulets and rills are often referred to as watersheds.
These are larger in the area.	These are small in area.

(ii) Dendritic and Trellis drainage pattern

Dendritic drainage pattern	Trellis drainage pattern
The drainage pattern resembling the branches of a tree is known as dendritic.	When the primary tributaries of rivers flow parallel to each other and secondary tributaries join them at right angles, the pattern is known as trellis.
The drainage pattern of Northern plain is the example of such pattern.	The drainage pattern of Himalayan mountain is the example of such pattern.

(iii) Radial and Centripetal drainage pattern

Radial drainage pattern	Centripetal drainage pattern
When the rivers originate from a hill and flow in all directions, the drainage pattern is known as ‘radial’.	When the rivers discharge their waters from all directions in a lake or depression, the pattern is known as ‘centripetal’.
The rivers originating from the Amarkantak range is the example of such pattern.	Sambhar Lake of Rajasthan is the example of such pattern.

(iv) Delta and Estuary

Delta	Estuary
A Delta is a triangular landmass formed at the mouth of the river.	An Estuary is a funnel shaped formed at the mouth of the river.
It is formed in the regions of low tides and coastal plains.	It is formed in the regions of high tides and rift valleys.
These are extremely fertile and support agriculture.	They provide fishing ground and support inland transportation.
The rivers like Ganga and Brahmaputra form deltas.	The rivers like Narmada and Tapi form estuaries.

Q2.What are the socio-economic advantages of inter-linking of rivers in India?

Answer

The socio-economic advantages of inter-linking of rivers in India are:
• The problems of floods and drought will get solved as excess water from an area can be transferred to water deficit areas.
• The inland waterway transportation will improve which will make the transportation of materials across the country easier.
• It will also help in imporving irrigational facilities which will increase the productivity.dro-electricity and fisheries activities.

Q3. Write three characteristics of the Peninsular river.

Answer

Three characteristics of the Peninsular river are:
• These rivers originate in Peninsular plateau and central highland.
• These are seasonal and dependent on monsoon rainfall.
• These rivers are smaller having fixed course with well adjusted valleys.

Q4. What are the important characteristic features of north Indian rivers? How are these different from Peninsular rivers?

Answer

The important characteristic features of north Indian rivers are:
• They originate in Himalayan mountain covered with glaciers.
• These rivers are perennial in nature because they receive water from glacier and rainfall.
• These rivers form deep gorges and V-shaped valleys in mountainous areas.
• It has long course, flowing through the rugged mountains experiencing headward erosion and river capturing.
• These rivers are young and youthful, active and deepening in the valleys.

These are different from peninsular rivers because of these reasons:
• The north Indian rivers have very large basins while peninsular rivers have relatively smaller basin.
• The north Indian rivers are perennial as they receive water from glaciers and rainfall while peninsular rivers receive their water only from monsoon rains.
• The north Indian rivers are antecedent and consequent leading to dendritic pattern in plains while peninsular rivers are super imposed, rejuvenated resulting in trellis, radial and rectangular patterns.
• The north Indian rivers are young and youthful, active and deepening in the valleys while peninsular rivers are old with graded profile, and have almost reached their base levels.

Q5.Suppose you are travelling from Haridwar to Siliguri along the foothills of the Himalayas. Name the important rivers you will come across. Describe the characteristics of any one of them.

Answer

If we are travelling from Haridwar to Siliguri along the foothills of the Himalayas we will come across Gomti, Ramganga, Rapti, Gandak, Kosi, Kamla, Saryu, Sharda, Ghaghra, Mahanadi and Ganga.
The characteristics of Gandak:
• It rises in the Nepal Himalayas between the Dhaulagiri and Mount Everest and drains the central part of Nepal
• It comprises two streams, namely Kaligandak and Trishulganga
• It enters the Ganga plain in Champaran district of Bihar and joins the Ganga at Sonpur near Patna.
• Its length is 630 Km.

Long Answer Type Questions:

Q1.How are rivers of India useful for India?
Answer:
Rivers are useful for us because:

• Water: Rivers carry water and nutrients to areas all around the earth. They play a very important part in the water cycle, acting as drainage channels for surface water. Rivers drain nearly 75% of the earth’s land surface.
• Habitats: Rivers provide excellent habitat and food for many of the earth’s organisms. Many rare plants and trees grow by rivers. Ducks, voles, otters and beavers make their homes on the river banks. Reeds and other plants like bulrushes grow along the river banks. Other animals use the river for food and drink. Birds such as kingfishers eat small fish from the river.
• Delta: River deltas have many different species of wildlife. Insects, mammals and birds use the delta for their homes and for food.
• Transport: Rivers provide travel routes for exploration, commerce and recreation.

Q2.Explain about Indus River System.
Answer:
The Indus System

• It is one of the largest river basins of the world, covering an area of 11,65,000 sq. km (in India it is 321, 289 sq. km) and a total length of 2,880 km (in India 1,114 km). The Indus also known as the Sindhu, is the westernmost of the Himalayan rivers in India.
• It originates from a glacier near Bokhar Chu (31°15′ N latitude and 81°40′ E longitude) in the Tibetan region at an altitude of 4,164 m in the Kailash mountain range.
• The Indus receives a number of Himalayan tributaries such as the Shyok, the Gilgit, the Zaskar, the Hunza, the Nubra, the Shigar, the Gasting and the Dras. It finally emerges out of the hills near Attock where it receives the Kabul river on its right bank. The other important tributaries joining the right bank of the Indus are the Khurram, the Tochi, the Gomal, the Viboa and the Sangar.
• They all originate in the Sulaiman ranges. The river flows southward and receives ‘Panjnad’ a little above Mithankot. The Panjnad is the name given to the five rivers of Punjab, namely the Satluj, the Beas, the Ravi, the Chenab and the Jhelum.
• It finally discharges into the Arabian Sea, east of Karachi.
• The Indus flows in India only through the Leh district in Jammu and Kashmir.

Q3.Explain about Ganga River System.
Answer:

The Ganga System:

1. The Ganga is the most important river of India both from the point of view of its basin and cultural significance. It rises in the Gangotri glacier near Gaumukh (3,900 m) in the Uttarkashi district of Uttarakhand. Here, it is known as the Bhagirathi. It cuts through the Central
and the Lesser Himalayas in narrow gorges.

2.  At Devaprayag, the Bhagirathi meets the Alaknanda; hereafter, it is known as the Ganga. The Alaknanda has its source in the Satopanth glacier above Badrinath. The Alaknanda consists of the Dhauli and the Vishnu Ganga which meet at Joshimath or Vishnu Prayag.

3. The river has a length of 2,525 km. It is shared by Uttarakhand (110 km) and Uttar Pradesh (1,450 km), Bihar (445 km) and West Bengal (520 km). The Ganga basin covers about 8.6 lakh sq. km area in India alone.

4. The Ganga river system is the largest in India having a number of perennial and non-perennial rivers originating in the Himalayas in the north and the Peninsula in the south, respectively. The Son is its major right bank tributary.

5. The important left bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda. The Yamuna, the westernmost and the longest tributary of the Ganga, has its source in the Yamunotri glacier on the western slopes of Banderpunch range (6,316 km).

6. The river finally discharges itself into the Bay of Bengal near the Sagar Island.

Q4.What factors determine volume of water in a river?
Answer:
Factors affecting the volume of water in a river:

1. An important factor affecting the volume of water in a river is the size of the drainage basin. A drainage basin in an area drained by one main river and its tributaries. If the drainage basin is large, the volume of water in the river will be more. When the drainage basin is large the surface run off flourished the river is more runoff in the amount of rainwater that flows on the ground and ultimately into the river or lake. On the other hand, if the drainage basin is small volume of water in the river will be less because there is less surface area for the rain to fall on.

2.Vegetation is also an important factor. Leaves of tress intercept rainwater and allow more water to sweep into the ground in groundwater. As a result, the amount of surface runoff reduces. Therefore, the volume of water in the river is less where vegetation is dense. Spare vegetation prevents rainwater from getting trapped in the leaves and
branches, thereby allowing more water to flow through as surface runoff. So, in areas with less vegetation volume of water is more.

3. Permeability of rocks: In area with permeable or porous rocks, much of the rainwater sweeps through the pores in the rocks into the ground. In such areas, surface run off is less and water flowing into the river channel will also be less.

4. Climate: In areas with hot and wet climate such as equatorial area, volume of water rivers will be high. However, the amount of water will be less in areas with dry climate receiving less rainfall. In areas with prominent wet or dry seasons, volume of water in the river will vary according to the amount of rainfall received.

Q5.Explain the different drainage patterns formed by rivers. Draw diagram of each drainage pattern with two examples of each.
Answer:
The drainage pattern formed by rivers are:
(a) Dendritic:
The drainage resembling, the branches of a tree is known as ‘dendritic’ the examples of which are the rivers of northern plains like Ganga, Yamuna, etc.

(b) Radial: When the rivers originate from a hill and flow in all directions, the drainage pattern is known as ‘radial’ or the dome-shaped pattern. The river originating from the Amarkanta range and central highlands present a good example of it.

(c) Trellis: When the primary tributaries of rivers flow parallel to each and secondary tributaries join them at right angles, the pattern is known as ‘trellis’ e.g. Peninsular river such as Godavari, Krishna etc.

(d)Centripetal: When the rivers discharge their waters from all directions in a lake or in depressions, it is known as ‘centrifugal’. These rivers form cascades/rapids and waterfalls.

Q6.Differentiate between:
(a) Himalayas rivers and the Peninsular rivers.
Answer:
Difference between Himalayas Rivers and the Peninsular rivers.

Aspects	Himalayan rivers	Peninsular rivers
Place of origin	Himalayan mountains covered with glaciers	Peninsular plateau and central highland
Nature of flow	Perennial; receive water from glacier and rainfall	Seasonal, dependent on monsoon rainfall
Type of drainage	Antecedent and consequent leading to dendritic pattern in plains.	Super imposed : rejuvenated resulting in trellis and rectangular pattern
Nature of river	Long course, flowing through the mountains. Experiencing headwater erosion and river capturing in plains meandering and shifting of course.	Smaller, fixed course with well adjusted valleys.
Catchment area	Very large basins	Relatively smaller basin
Area of river	Young and youthful, active and deepening of the valleys.	Old rivers with graded profile, and have almost reached their base levels
Examples	Indus, Ganges and Brahmaputra and their tributaries.	Peninsular Plateau Chambal, Betwa, Central Highlands, Godavari, Krishna, etc.

(b) Consequent rivers and Antecedent rivers
Answer:
Difference between Consequent rivers and Antecedent rivers

Basis	Consequent rivers	Antecedent rivers
Shape	These rivers maintain their original shapes, deposits, the rise of land due to folding. The rivers keep on following in the same direction.	It is an uplift area the rivers flow in the direction resulting as consequent of the slope
Age	These rivers are older than the old mountain.	These rivers are formed after the uplift of an area.

Gorges	These rivers cut deep gorges due to down cutting.	These rivers do not form gorges.
Examples	Trans- Himalayan rivers such as Indus, Satluj, represent consequent rivers.	The eastward flowing river of peninsular plateau which flow according to the slope are antecedent rivers.

Q7.Differentiate between canyon, gorge and river valley.
Answer:
A canyon is a deep valley with steep sides, think of the grand canyon most famously to visualise what this is. A gorge is a deep ravine, which usually has a river running through it—though this doesn’t have to be the case. Finally a valley is any depression, usually of a certain length, in the surface of the land and often contains a river. So, a canyon is a specific type of valley, with particularly steep sides. A gorge is a particularly deep depression, and will usually contain a river.

SHORT ANSWER TYPE QUESTION:

Q1.If a person is to travel to Lakshadweep, from which coastal plain does he prefer and why?
Answer
The person will prefer to travel from the western coastal plains because the Lakshdweep islands are situated in Arabian Sea which distance is lowest from this coast. Therefore, it will take the least time to reach the Lakshadweep.

Q2. Where in India will you find a cold desert? Name some important ranges of this region.

Answer

The cold desert in India is located in the north eastern part of the Kashmir Himalayas, which lies between the Greater Himalayas and the Karakoram ranges.

Q3.Why is the western coastal plain is devoid of any delta?

Answer

The western coastal plains are narrow and have steep slope. The rivers flow rapidly in one part and hence they don’t form any deltas. Therefore, the western coastal plain is devoid of any delta.

Q4.Make a comparison of the island groups of the Arabian Sea and the Bay of Bengal.

Answer

Island groups of the Arabian Sea	Island groups of the Bay of Bengal
This island group consists of about 36 islands of which 11 are inhabited.	This island groups consist of about 572 islands/islets.
These are situated between 8°N-12°N and 71°E -74°E longitude.	These are situated roughly between 6°N-14°N and 92°E -94°E.
The entire group of islands is broadly divided by the Eleventh degree channel, north of which is the Amini Island and to the south of the Canannore Island.	The entire group of island is divided into two broad categories – the Andaman in the north and the Nicobar in the south.
The entire island group is built of coral deposits.	These islands are an elevated portion of submarine mountains.
Minicoy is the largest island with an area of 453 sq. km.	The two principal groups of islands include the Ritchie’s archipelago and the Labrynth island.

Q5.What are the important geomorphological features found in the river valley plains?

Answer

The river valley plains are formed by the alluvial deposits brought by the rivers. The important geomorphological features found in the river valley plains are:

• Bhabar is a narrow belt ranging between 8-10 km parallel to the Shiwalik foothills at the break-up of the slope.

• Terai: South of the Bhabar is the Tarai belt, with an approximate width of 10-20 km where most of the streams and rivers re-emerge without having any properly demarcated channel, thereby, creating marshy and swampy conditions known as the Tarai.
→ This has a luxurious growth of natural vegetation and houses a varied wild life.

• Bhangar: It is composed of old alluvium. These areas are less prone to flooding and less fertile as well.

• Khadar: It is composed of new alluvial deposits. These areas are prone to flooding and are very fertile

• Delta:  A river delta is a landform that occurs at the mouth of a river near where the river flows into the ocean. For example, the famous Sunderbans delta.

Q6. If you move from Badrinath to Sunderbans delta along the course of the river Ganga, what major geomorphological features will you come across?

Answer

Badrinath is situated along Ganga river. The Sunderban delta is on the mouth of Ganga and Brahmaputra in Bay of Bengal. If we are moving from Badrinath to Sunderbans delta along the course of the river Ganga, we will come across various of geomorphological features. As we start moving we will come across gorges, V-shaped valleys, rapids, waterfalls, etc. We will also see places where tributaries meet main river Ganga. After sometime, we will enter into northern plains. We will see various erosional and depositional landforms such as sand bars, meanders, oxbow lakes and braided channels. At last, we will reach our destination, swampy and marshy area known as Sunderbans delta formed by the Ganga and Brahmaputra river.

Long Answer Type Questions:

Q1.Write a detailed on Kashmir or north-western Himalayas.
Answer:
Kashmir or North-western Himalayas:

• Region extents over Jammu and Kashmir, Himachal Pradesh and Uttaranchal.
• It comprises of Ladakh, Zaskar and Pir Panjal.
• The north-eastern parts of Kashmir Himalayas is a cold desert which lies between greater Himalayas and Karakoram ranges.
•  Between Pir Panjal and Great Himalayas in Dal Lake and Valley of Kashmir.
• Important Glaciers here are:
  • Siachen
  • Baltora
  • Babura
  • Hispar.
• Kashmir valleys are known for Karewas. Karewas are thick deposits of glacial clay and other material embedded with moraines (Zafran-Saffron is cultivated here):
• Important passes: Zoji La on the Great Himalayas, Banihal on Pir Panjal range, Photu La-Zaskar range, Kharaung La on Ladakh range. Thadala, Nitila, Lepulekh in Uttaranchal Nathula in Sikkim in Himachal Pradesh.
• Himalayas are spread between river Indus to river Mahi. The total extent of western Himalayas is 700 km and 400 km in width.
• Kashmir Himalayas, Punjab Himalayas and Kumaon Himalayas are its sub¬division.
• The important lakes are: Dal lake and Wular lake (in Jammu and Kashmir and they are freshwater lakes), Pangong Tso, Tso Moriri ( they are salt water lakes and they are situated in Jammu and Kashmir.
• Important rivers: Indus, Jhelum and Chenab.
• Important pilgrimages Vaishno Devi, Amaranth and Charar-e-Sharif.
• The southernmost part of the region has longitudinal valleys known as Duns, e.g. Jammu Dun and Pathankot Dun.

Q2.Explain the characteristics or features of Northern plains?
Answer:
The Northern Plains-

• These plains extend approximately 3,200 from the east to the west.
• The average width of these plains varies between 150-300 km.
• The maximum depth of alluvium deposits varies between 1,000-2,000 m.
• The area covered by northern plains is 7 lakhs square km and is most densely populated region of country.
  From north to South, these plains can be divided into three sub divisions: Bhabar, Tarai and Alluvial Plains. The alluvial plains can be further divided into the Khadar and the Bhangar.

Bhabar

• It is a narrow belt ranging between 8-16 km parallel to the Shiwalik foothills at the breaking of the slopes.
• The streams and rivers coming from the mountain deposit heavy materials of rocks and boulders and at times, disappear in this zone.

Tarai

• Its approximate width is of 20-30 km where most of the streams and river re-emerge without having any properly demarcated channel, thereby, creating marshy and swampy condition known as the Tarai.
• It has a luxurious growth of natural vegetation and houses a varied wild life.

Alluvial Plains

• These plains have characteristic features of mature stage of fluvial erosional and depositional landforms such as sand bars, meanders, ox- bow lakes and braided channels. The Brahmaputra plains are known for their riverine islands and sand bars.
• The mouths of these mighty rivers also form some of the largest deltas of the world, for example, the famous Sunderbans delta.
• These river valley plains have a fertile alluvial soil cover which supports a variety of crops like wheat, rice, sugarcane and jute, and hence supports a large population.

Q3.Explain the physical features of coastal plains.
Answer:
On the basis of the location and active geomorphological processes, it can be broadly divided into two:

• The western coastal plains;
• The eastern coastal plains.

The western coastal plains are an example of submerged coastal plain. It is a narrow belt and provides natural conditions for the development of ports and harbours. Kandla, Mazagaon, JLN port. Navha Sheva, Marmagao, Mangalore, Cochin, etc. are some of the important natural ports located along the west coast.

Extending from the Gujarat coast in the north to the Kerala coast in the south, the western coast may be divided into following divisions – the Kachchh and Kathiawar coast in Gujarat, Konkan coast in Maharashtra, Goan coast and Malabar coast in Karnataka and Kerala respectively. As compared to the western coastal plain, the eastern coastal plain is broader and is an example of an emergent coast.

There are well- developed deltas here, formed by the rivers flowing eastward in to the Bay of Bengal. These include the deltas of the Mahanadi, the Godavari, the Krishna and the Kaveri. Because of its emergent nature, it has less number of ports and harbours. The continental shelf extends up to 500 km into the sea, which makes it difficult for the development of good ports and harbours.

It is believed that the city of Dwaraka which was once a part of the Indian mainland situated along the west coast is submerged under water. Because of this submergence it is a narrow belt and provides natural conditions for the development of ports and harbours. Kandla, Mazagaon, JLN port Navha Sheva, Marmagao, Mangalore, Cochin, etc. are some of the important natural ports located along the west coast.

Q4.How are Arunachal, Himachal, Purvachal and Uttaranchal Himalayas different from each other?
Answer
Arunachal Himalayas

• These extend from east of Bhutan to Diphu pass in East.
• Important peaks are- Kangtu and Namcha Barwa.
• They are bisected by fast flowing rivers forming deep gorges.
• Brahmaputra flows through deep a gorge after crossing Namcha Barwa.
• Subansiri, Dihang, Dibang and Lohit are the important rivers. Perennial rivers have high rate of fall which helps to generate hydro-electricity.

The Himachal and Uttarakhand Himalayas-

• It lies between river Ravi and Kali in the east.
• Northernmost part is the extension of the Ladakh desert.
• All these ranges Nimadi, Himachal and Chivalric are prominent here.
• Hill stations are Dharamshala, Mussoorie, Shimla, Ranikhet and Almora.
• Shiwaliks are important for dun formation. For example- Kalka dun, Nalagarh dun (Dehradun is the largest- dun, its length is 35-45 km and width is 22-25 km.)
• Tribes common are Dhotia’s which migrates to higher region in summer.
• Valley of flowers- Nanda devi is also situated here.
• Gail’s, the Manipur Pilgrimages common are Kedarnath, Badrinath, Hemkund Sahib.

The Eastern Hills and mountains or Purvachal.

• General alignment from the north to south direction.
• In north, they are known as Patkai Bum, Naga hills, the Manipur hills and in the south, as Mizo or Lushai Hills. This forms Purvanchal range.
• Most of these ranges are separated from each other by numerous small rivers.
• The barak is an important river in Manipur and Mizoram.
• Mizoram has a large lake known as ‘loktak lake is made up of soft unconsolidated deposits.
• Mizoram and Manipur are tributary of Barak river, which is the turn tributary of Meghna rivers in eastern part of Manipur are tributaries of Chindwin which is in turn is a tributary of Ireawady of Myanmar.

Q5.Differentiate between:
(i) Bhabar and Tarai
Answer:
Difference between Bhabar and Tarai.

Bhabar	Basis	Tarai
It lies along the foot of shiwalik from Indus to Tista	Location	It lies to the south of Bhabar and runs parallel to it.
It is 8 to 16 km wide.	Width	It is 20-30 km wide.
It comprises of pebbles studded rocks in the shape of porous bed.	Composition	It is composed of firmer alluvial particles and is covered by forests.
Due to the porousity of rocks the stream disappear and flow underground.	Appearance	The underground streams of Bhabar reappear here giving rise to a wet marshian.
It is not suitable for agriculture.	Suitability	It is reclaimed for agriculture purpose.

(ii) Bhangar and Khadar
Answer:
Difference between Bhangar and Khadar

Bhangar	Basis	Khadar
It is a highland composed of old alluvium.	Composition	It’s a lowland composed of new alluvium.
It is always above the level of flood plains.	Flood	It is flooded almost every year.
It comprises of canvanious nodules	Fertility	It comprises of clay soil which is normally fertile
It is not much suited for agriculture.	Suitability	It is suited for agriculture. Intensive agriculture is practiced.
It is known as dhaya in Punjab.	Other name	It is known as bate in Punjab.

(iii) Western Ghats and Eastern Ghats
Answer:
Difference between Western Ghats and Eastern Ghats;

Western Ghats	Basis	Eastern Ghats
They form continuous chain from Gulf of Combay to Kanniyakumari.	Location	They form a discontinuous chain of low hills from Odisha to Coromandel coast.
They are having an elevation of 900-1100m.	Peaks	They are denuded peaks and have lesser elevation than 900 km.
They are divided as four regions or the four hills Sahyadri hills in Maharashtra, Nilgiri in Karnataka and Tamil Nadu, Anaimalai hills and Cardamom hills in Kerala.	Hills	Some of the important ranges include the Javadi hills, the Palconda range, the Nallamala hills, the Mahendragiri hills, etc.
The western ghats get southward monsoon.	Rainfall	The eastern ghat gets rainfall from north-east monsoon.
The highest peak in western ghat is Anamudi (2695 m)	Highest Peak	Highest peak of eastern ghat is Mahendragiri (1501 m)
The height of the mountain increases from north to south.	Change in height	Height increases from south to north.
The westward flowing river are Narmada and Tapi.	Rivers	Eastward flowing rivers are Godavari Krishna, Kaveri, Mahanadi, etc.

(iv) Peninsular Plateau and Indo-Gangetic Plateau
Answer:
Difference between Peninsular Plateau and Indo-Gangetic Plateau

Peninsular Plateau	Basis	Indo-Gangnetic Plateau
It is triangular plateau bounded by Vindhyas western ghats, and eastern ghats.	Stretch	It is alluvial plain stretching from Punjab to Assam valley.
The relief of this plateau is uneven. Its average height is more than 600 m above the sea level.	Level	This is a level plain for about 200 m in height above the sea level.
The climate is hot and humid.	Climate	The summers are hot and winters are cold.
Kaveri, Krishna, Godavari, Mahanadi, Narmada, Tapi are seasonal rivers.	Rivers	Ganga, Yamuna, Brahmaputra are perennial rivers.
Area has black soil.	Soil	Alluvial soil is found.
Known as storehouse of minerals and important for industries.	Known for	Known for agriculture and provide employment to people.

(v) Western Coastal Plains and Eastern Coastal Plains
Answer:
Difference between Western Coastal Plains and Eastern Coastal Plains

Western coastal plain	Basis	Eastern coastal plain
They lie between western ghats and Arabian sea.	Location	They lie between eastern ghats and bay of Bengal.
They are narrow alluvial plain which are separate by hilly terrains.	Width	They are wider plain (80-120 km) with well developed deltas of the rivers.
The western coastal plains are further divided into two parts: Konkan coast, Malabar coast	Furtherclassification	They are further divided as northern circus and Coromandel coast.
They are known for lagoons estuary and kayals (backwater), which are known for fishing and Inland transportation.	Known For	They are known for deltas formed by the rivers and is more suitable for agriculture.
They receive rainfall from south­west monsoons.	Rainfall	They receive rainfall by retreating or north-west monsoon.
The important rivers are Narmada, Tapi	Rivers	The important rivers are Krishna, Kaveri, Mahanadi, etc.
They are submerged coast.	Merging	They are emergent coast.

(vi) Northern Plains and Coastal Plains
Answer:
Difference between Northern Plains and Coastal Plains

Northern Plains	Basis	Coastal Plains
They are located on foot hills of Himalayas and above peninsular plateau.	Location	They lie between Arabian Sea, Western Ghats and Eastern Ghats and Bay of Bengal.
They spread between the area of 3200 square km and the width is 240-320 km.	Stretch	They are spread from Gujarat to Kanniyakumari and Odisha to Kanniyakumari.
Rivers originating from Himalayas and peninsular plateau has form these plains by depositing sediments brought by rivers.	Rivers	Most of the rivers originating from peninsular plateau like Krishna, Kaveri, Godavari, Mahanadi move eastward and form delta whereas Narmada and Tapi move westward from Estuaries.
Due to fertile alluvial soil and water supply they are known for agriculture.	Suitability	They are drained by perinial rivers and are important for fishing, lagoons, and harbours.
They are divided as Indus plains, Ganga plains and Brahmaputra plains.	Divisions	They are divided as Konkan coast and Malabar coast, Northern Circar on eastern side and Coromandel coast.
They are important for riverine features like natural leaves, sand bars, etc.	Known for	They are important for ports, harbours, kayals and backwaters.

(vii) Himalayas and Central Highlands
Answer:
Difference between Himalayas and Central Highlands

Himalayas	Basis	Central Highlands
They are the young fold mountains of comparatively recent origin.	Young vs. Old	They are part of oldest structure of Indian subcontinents.
They are the world’s highest mountains and the Mount Everest is the highest peak of the world.	Height	They are formed of low hills and no high peak is there worth mentioning in the area.
The mighty rivers like Indus, Ganga, Brahmaputra originate beyond the Himalayas.	Rivers	Quite a few rivers like Tapi, Chambal, Betwa, Narmada, originate from these highland.
They are made up of sedimentary rocks.	Composition	They are formed by Igneous and metamorphic rocks.
They are formed at the edge of northern plains.	Location	They are formed at the edge of Deccan Plateau.
Important hill stations are Srinagar, Shimla, Dhalauzi, Dharamshala, Mussoorie, etc.	Hill stations	They are no well-known hill stations.
Himalayas are known for glaciers and perennial rivers.	Glaciers and rivers	No glaciers and non- perennial river are there.
They have beautiful passes and river valleys.	Scenicbeauty	They are low-lying hills with less common features.

SHORT ANSWER TYPE QUESTION:

Q1. Does India need to have more than one standard time? If yes, why do you think so?
Answer
Yes, as per my thinking India need to have more than one standard time because there is a time gap of about 2 hours between the easternmost parts to westernmost parts of the country. The longitudinal extent of India is large i.e., 30° approximately. Therefore, we need to more than one time zones. There are some countries where there is more than one standard meridian due to their vast east-to-west extent. For example, the USA has seven time zones.

Q2. What are the implications of India having a long coastline?

Answer

Peninsular part of India extends towards the Indian Ocean. This has provided the country with a coastline of 6,100 km in the mainland and 7,517 km in the entire geographical coast of the mainland plus the island groups Andaman and Nicobar and the Lakshadweep. This helps India in establishing close contact with West Asia, Africa and Europe from the western coast and with Southeast and East Asia from the eastern coast. However, it also forces India to have regular monitoring of coastline for the protection from external forces.

Q3. How is the latitudinal spread of India advantageous to her?

Answer

The latitudinal spread of India advantageous to her in many ways:
• The southern part of the country lies within the tropics and the northern part lies in the sub-tropical zone or the warm temperate zone.
• This is responsible for large variations in land forms, climate, soil types and natural vegetation in the country

Q4.While the sun rises earlier in the east, say Nagaland and also sets earlier, how do the watches at Kohima and New Delhi show the same time?

Answer

India follows one standard time for the whole country. 82°30′ E has been selected as the ‘standard meridian’ of India. Indian Standard Time is ahead of Greenwich Mean Time by 5 hours and 30 minutes. Therefore, while in Nagaland sun rises earlier and also sets earlier, but the watches at Kohima and New Delhi show the same time.

Long Answer Type Questions :

Q1.Size of India has endowed India with unique physical diversity. Substantiate.
Answer:
The size of India has endowed her with great physical diversity. The presence of lofty mountains in the north; large rivers such as Ganga, Brahmaputra, Mahanadi, Krishna, Godavari and Kaveri; green forested hills in the north-east and south India; and the vast sandy expanse of Marusthali is very impressive. It is bounded by the Himalayas in the north, Hindukush and Sulaiman ranges in the north-west, Purvachal hills in the north-east and by the large expanse of the Indian ocean in the south. The Himalayas, together with other ranges, have acted as a formidable physical barrier in the past. Except for a few mountain passes such as the Khyber, the Bolan, the Shipkila, the Nathula, the Bomdila, etc. it was difficult to cross it.

It has contributed towards the evolving of a unique regional identity of the Indian subcontinent. Peninsular part of India extends towards the Indian Ocean. This has provided the country with a coastline of 6,100 km in the mainland and 7,517 km in the entire geographical coast of the mainland plus the island groups Andaman and Nicobar located in the Bay of Bengal and the Lakshadweep in the Arabian Sea. Thus India, as a country, is a physically diverse land providing occurrence of varied resources.

Q2.Explain in detail about size and extension of India.
Answer:
Total area of India republic is 32,87,263 sq. Km. From the point of view of area, India is seventh largest country of the world. Its population is 1210 million and it has second position in the world after china from population point of view. The mainland of India, extends from Kashmir in the north to Kanniyakumari in the south and Arunachal Pradesh in the east to Gujarat in the west. India extends from territorial limit further extends towards the sea upto 12 nautical miles (about 21.9 km) from the coast. India lies entirely in the Northern hemisphere. The mainland extends between latitudes 8 4′ N (Kanniyakumari, Cape Caverian) and 37 6′ N ( Indira col, Jammu and Kashmir) and longitudes 68 7′ E (Dwarka, Gujarat) and 97 25′ E (Sadiya, Arunachal Pradesh).

Longitudinal extent of India is 68 7′ to 97 25′ E -(29 ). India’s land length is 15,200 km and it has a coastline of 6,100 km in the mainland and 7,517 km in the entire geographical coast of the mainland plus the island groups Andaman and Nicobar located in the Bay of Bengal and the Lakshadweep in the Arabian Sea Thus India, as a country, is a physically diverse land providing occurrence of varied resources. India is located in the south-central part of the continent of Asia, bordering the Indian Ocean and its two arms extending in the form of Bay of Bengal and the Arabian Sea. This maritime location of Peninsular India has provided links to its neighbouring regions through the sea and air routes.

Q3.Differentiate the following:
(a) Gulf and Strait
(b) Gulf and Bay
Answer:

(a) Gulf and strait are two terms that are often discussed when it comes to geography. As gulfs and straits are both common features in seafaring. It is easy to confuse these two words. However, each feature has their own unique characteristics which in turn give them a unique purpose in the history of mankind.

• Meaning: A gulf is a large body of water almost encircled by land except for a small mouth that opens out to the sea. A strait is a strip of water that separates two lands or two large bodies of water.
• Use: Straits are used for navigational purposes and have played an integral part when it comes to shipping routes. Gulfs are more useful for human settlements, as such areas provide easy access to the ocean while being well protected as well.
• Association: Gulfs can be easily associated with inland bodies of water as well as the ocean. Straits are mostly discussed with regards to the ocean.

(b) Difference between Gulf and Bay

• A bay is not as enclosed by land masses as a gulf.
• Gulf is formed because of erosion of the rocks as water makes inroads into adjoining land.
• Gulfs take any form while bays are mostly oval or round shaped.

SHORT ANSWER TYPE QUESTION:

Q1. What is biodiversity?

Answer

Biodiversity refers to the varieties of plants, animals and micro-organisms, the genes they contain and the ecosystems they form.

Q2.What are the different levels of biodiversity?

Answer

There are three different levels of biodiversity:
• Genetic diversity: It refers to the variation of genes within species.
• Species diversity: It refers to the variety of species.
• Ecosystem diversity: It refers to the number of ecosystems in a certain area.

Q3. What do you understand by ‘hotspots’?

Answer

The areas rich in species diversity are called hotspots of diversity.

Q4. Discuss briefly the importance of animals to human kind.

Answer
Animals capture and store energy, produce and decompose organic materials, help to cycle water and nutrients throughout the ecosystem, fix atmospheric gases and help regulate the climate.

Q5.What do you understand by ‘exotic species’?

Answer

Species which are not the natural inhabitants of the local habitat but are introduced into the system are called exotic species.

Q6.What are the roles played by biodiversity in the shaping of nature?

Answer

Biodiversity has contributed in many ways to the development of human culture and, in turn, human communities have played a major role in shaping the diversity of nature at the genetic, species and ecological levels. Biodiversity plays the following roles:

• Ecological Role of Biodiversity: Species capture and store energy, produce and decompose organic materials, help to cycle water and nutrients throughout the ecosystem, fix atmospheric gases and help regulate the climate. These functions are important for ecosystem function and human survival.

• Economic Role of Biodiversity: Biodiversity is seen as a reservoir of resources to be drawn upon for the manufacture of food, pharmaceutical, and cosmetic products.

• Scientific Role of Biodiversity: Biodiversity also helps in understanding how life functions and the role of each species in sustaining ecosystems of which we are also a species.

Q7. What are the major factors that are responsible for the loss of biodiversity? What steps are needed to prevent them?

Answer

The major factors that are responsible for the loss of biodiversity are:

• Growth in human population has increased the rate of consumption of natural resources which accelerated the loss of species and habitation in different parts of the world.
• Overexploitation of resources and deforestation.
• Destruction of natural habitats.
• Natural calamities such as earthquakes, floods, volcanic eruptions, forest fires, droughts, etc.
• Pesticides and other pollutants such as hydrocarbons and toxic heavy metals.

The steps which are needed to prevent them are:
• Efforts should be made to preserve the species that are endangered.
• Prevention of extinction requires proper planning and management.
• Varieties of food crops, forage plants, timber trees, livestock, animals and their wild relatives should be preserved.
• Each country should identify habitats of wild relatives and ensure their protection.
• Habitats where species feed, breed, rest and nurse their young should be safeguarded and protected.
• International trade in wild plants and animals be regulated.

Long Answer Type Questions:

Q1.In how many categories has the International Union of Conservation of Nature and Natural Resources (IUCN) classified the threatened species of plants and animals?
Answer:
The International Union of Conservation of Nature and Natural Resources (IUCN) has classified the threatened species of plants and animals into three categories for the purpose of their conservation.

• Endangered species: Endangered species includes those species which are in danger of extinction. The IUCN publishes information about endangered species worldwide as the Red List of threatened species.
• Vulnerable species: Vulnerable species includes the species which are likely to be in danger of extinction in near future if the factors threatening to their extinction continue. Survival of these species is not assured as their population has reduced greatly.
• Rare species: Rare species are those species whose population is very small in the world. They are confined to limited areas or thinly scattered over a wider area.

Q2.How do natural calamities and illegal hunting harm biodiversity?
Answer:
Natural Calamities: Natural calamities such as earthquakes, floods, volcanic eruptions, forest fires, droughts, etc. cause damage to the flora and fauna of the earth, bringing change to the biodiversity of respective affected regions. Pesticides and other pollutants such as hydrocarbons and toxic heavy metals destroy the weak and sensitive species. Species which are not the natural inhabitants of the local habitat but are introduced into the system, are called exotic species. There are many examples when a natural biotic community of the ecosystem suffered extensive damage because of the introduction of exotic species. During the last few decades, some animals like tigers, elephants, rhinoceros, crocodiles, minks and birds were hunted mercilessly by poachers for their horn, tusks, hides, etc. It has resulted in the rendering of certain types of organisms as endangered category. Illegal Hunting: Hunting and habitat destruction contributed to a second wave of extinctions after European settlement, including:

• 16 land birds (nine species and seven subspecies).
• One of three native bat species.
• One fish.
• At least 12 invertebrates, such as snails and insects.

SHORT ANSWER TYPE QUESTION:

Q1. What do you understand by the term ‘ecology’?

Answer

Ecology is a scientific study of the interactions of organisms with their physical environment and with each other.

Q2. What is an ecological system? Identify the major types of ecosystems in the world.

Answer

The interactions of a particular group of organisms with abiotic factors within a particular habitat resulting in clearly defined energy flows and material cycles on land, water and air, are called ecological systems.
Ecosystems are of two major types:
• Terrestrial
• Aquatic

Q3.What is a food-chain? Give one example of a grazing food-chain identifying the various levels.

Answer

Thes sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as the food-chain.
Grass (first level) is eaten by deer (intermediate level) is eaten by lion (last level).

Q4. What do you understand by the term ‘food web’? Give examples.

Answer

A network of food chains mixed together to form a food web. For example, a mouse feeding on grain may be eaten by different secondary consumers (carnivores) and these carnivores may be eaten
by other different tertiary consumers (top carnivores). 

Q5. What is a biome?

Answer

A biome is a plant and animal community that covers a large geographical area.

Q6. What are bio-geochemical cycles? Explain how nitrogen is fixed in the atmosphere.

Answer

The balance of the chemical elements is maintained by a cyclic passage through the tissues of plants and animals. The cycle starts by absorbing the chemical elements by the organism and is returned to the air, water and soil through decomposition. These cycles are largely energised by solar insolation. The cyclic movements of chemical elements of the biosphere between the organism and the
environment are referred to as biogeochemical cycles. Bio refers to living organisms and geo to rocks, soil, air and water of the earth.
Ninety per cent of fixed nitrogen is biological. The principal source of free nitrogen is the action of soil micro-organisms and associated plant roots on atmospheric nitrogen found in pore spaces of the soil. Nitrogen can also be fixed in the atmosphere by lightning and cosmic radiation. In the oceans, some marine animals can fix it. 

Q7. What is an ecological balance? Discuss the important measures needed to prevent ecological imbalances.
Answer

Ecological balance is a state of dynamic equilibrium within a community of organisms in a habitat or ecosystem. It can happen when the diversity of the living organisms remains relatively stable.

Ecological imbalances: Ecological balance may be disturbed due to the introduction of new species, natural hazards or human causes.
The important measures to prevent ecological imbalances are:
• By not interfering in nature.
• By controlling population.
• By reusing and recycling things.
• By using natural resources judiciously.
• Afforestation should be encouraged.
Proper knowledge and management are necessary for protecting and conserving the ecosystems.

Long Answer Type Questions

Q1.Explain in detail about carbon cycle.
Answer:
The Carbon Cycle: Carbon is one of the basic elements of all living organisms. It forms the basic constituent of all the organic compounds. The biosphere contains over half a million carbon compounds in them. The carbon cycle is mainly the conversion of carbon dioxide. This conversion is initiated by the fixation of carbon dioxide from the atmosphere through photosynthesis. Such conversion results in the production of carbohydrate, glucose that may be converted to other organic compounds such as sucrose, starch, cellulose, etc. Here, some of the carbohydrates are utilised directly by the plant itself. During this process, more carbon dioxide is generated and is released through its leaves or roots during the day.

The remaining carbohydrates not being utilised by the plant become part of the plant tissue. Plant tissues are either being eaten by the herbivorous animals or get decomposed by the micro- organisms. The herbivores convert some of the consumed carbohydrates into carbon dioxide for release into the air through respiration. The micro-organisms decompose the remaining carbohydrates after the animal dies. The carbohydrates that are decomposed by the micro-organisms then get oxidised into carbon dioxide and are returned to the atmosphere.

Q2.Explain in detail about food chain.
Answer:
Food Chain: This sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as the food-chain. Transfer of energy that occurs during the process of a food chain from one level to another is known as flow of energy. The food- chains get interlocked with one another. This inter- connecting network of species is known as food web. For example, a plant eating beetle feeding on a paddy stalk is eaten by a frog, which is, in turn, eaten by a snake, which is then consumed by a hawk. This sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as the food-chain.

• Producers: The producers include all the green plants, which manufacture their own food through photosynthesis.
• Primary consumers: The primary consumers include herbivorous animals like deer, goats, mice and all plant-eating animals.
• Carnivores: The carnivores include all the flesh-eating animals like snakes, tigers and lions. Certain carnivores that feed also on carnivores are known as top carnivores like hawks and mongooses.
• Decomposers: Decomposers are those that feed on dead organisms (for example, scavengers like vultures and crows), and further breaking down of the dead matter by other decomposing agents like bacteria and various micro-organisms.

Generally, two types of food-chains are recognised: grazing food-chain and detritus food-chain.

• Grazing food chain: In a grazing food- chain, the first level starts with plants as producers and ends with carnivores as consumers at the last level, with the herbivores being at the intermediate level. There is a loss of energy at each level which may be through respiration, excretion or decomposition. The levels involved in a food- chain range between three to five and energy is lost at each level.
• A detritus food-chain: A detritus food chain is based on autotrophs energy capture initiated by grazing animals and involves the decomposition or breaking down of organic wastes and dead matter derived from the grazing food-chain.

Q3.Explain about the working and structure of ecosystem.
Answer:
The structure of an ecosystem involves a description of the available plant and animal species. From a structural point of view, all ecosystems consist of abiotic and biotic factors. Abiotic factors include rainfall, temperature, sunlight, atmospheric humidity, soil conditions, inorganic substances (carbon dioxide, water, nitrogen, calcium, phosphorus, potassium, etc.). Biotic factors include the producers, the consumers (primary, secondary, tertiary) and the decomposers. The producers include all the green plants, which manufacture their own food through photosynthesis.

The primary consumers include herbivorous animals like deer, goat, mice and all plant-eating animals. The carnivores include all the flesh-eating animals like snakes, tigers and lions. Certain carnivores that feed also on carnivores are known as top carnivores like hawks and mongooses. Decomposers are those that feed on dead organisms (for example, scavengers like vultures and crows), and further breaking down of the dead matter by other decomposing agents like bacteria and various micro- organisms.

Q4.Explain in detail about nitrogen cycle.
Answer:
Nitrogen is a major constituent of the atmosphere comprising about seventy- nine per cent of the atmospheric gases. It is also an essential constituent of different organic compounds such as the amino acids, nucleic acids, proteins, vitamins and pigments. Only a few types of organisms like certain species of soil bacteria and blue green algae are capable of utilising it directly in its gaseous form. Generally, nitrogen is usable only . after it is fixed. Ninety percent of fixed nitrogen is biological. The principal source of free nitrogen is the action of soil micro-organisms and associated plant roots on atmospheric nitrogen found in pore spaces of the soil.

Nitrogen can also be fixed in the atmosphere by lightning and cosmic radiation. In the oceans, some marine animals can fix it. After atmospheric nitrogen has been fixed into an available form, green plants can assimilate it. Herbivorous animals feeding on plants, in turn, consume some of it. Dead plants and animals, excretion of nitrogenous wastes are converted into nitrites by the action of bacteria present in the soil. Some bacteria can even convert nitrites into nitrates that can be used again by green plants. There are still other types of bacteria capable of converting nitrates into free nitrogen, a process known as denitrification.

Q5.Explain the features of different forest biomes of the world.
Answer:
Forest biomes are of following types:

1. Tropical Equatorial Forest: Found in 10° N-S
Temp. 20-25°C, evenly distributed Acidic, poor in nutrients Rich in nutrients

2. Tropical Deciduous Forest: Found in 10°-25° N-S
Temp. 25-30°C, Rainfall, ave. ann. 1,000 mm, seasonal

3. Temperate: Found in Eastern North America, N.E. Asia, Western and Central Europe
Temp. 20-30° C, Rainfall evenly distributed 750- 1,500 mm, Well- defined seasons and distinct winter. Fertile, en-riched with decaying litter

4. Boreal: Found in Broad belt of Eurasia and North America (parts of Siberia, Alaska, Canada and Scandinavia).
Short moist moderately warm summers and long cold dry winter; very low temperatures. Precipitation mostly snowfall 400 -1,000 mm.
Acidic and poor in nutrients, thin soil cover.
Rich in nutrients with little or no organic matter.

SHORT ANSWER TYPE QUESTION:

Q1. What are waves?
Answer
Waves are energy, not the water which moves across the ocean surface. It generated by wind driving against water.

Q2. Where do waves in the ocean get their energy from?

Answer

Wind provides energy to the waves. Wind causes waves to travel in the ocean and the energy is released on shorelines.

Q3. What are tides?

Answer

The periodical rise and fall of the sea level, once or twice a day, mainly due to the attraction of the sun and the moon, is called a tide.

Q4. How are tides caused?

Answer

The tides are caused by the gravitational pull of the sun and the moon and the centrifugal force

Q5.How are tides related to navigation?

Answer

Tides helps the navigators and fishermen plan their activities. Tidal flows are of great importance in navigation. Tidal heights are very important, especially harbours near rivers and within estuaries having shallow ‘bars’ at the entrance, which prevent ships and boats from entering into the harbour.

Q6. How do currents affect the temperature? How does it affect the temperature of coastal areas in the N. W. Europe?

Answer

The currents directly affect the temperature. The temperature varies depending on whether currents are warm or cold:
• Cold currents bring cold water into warm water areas. These currents are usually found on the west coast of the continents in the low and middle latitudes (true in both hemispheres) and on the east coast in the higher latitudes in the Northern Hemisphere
• Warm currents bring warm water into cold water areas and are usually observed on the east coast of continents in the low and middle latitudes (true in both hemispheres). In the northern hemisphere they are found on the west coasts of continents in high latitudes.

In North West Europe, warm currents are present which increase the temperature in coastal areas in the North West Europe.

Q7.What are the causes of currents?
Answer

Oceans currents are caused by two forces mainly:
(i) primary forces that initiate the movement of water
(ii) secondary forces that influence the currents to flow.

The primary forces that influence the currents are:

• Heating by solar energy:  Heating by solar energy causes the water to expand. That is why, near the equator the ocean water is about 8 cm higher in level than in the middle latitudes. This causes a very slight gradient and water tends to flow down the slope.

• Wind: It blowing on the surface of the ocean pushes the water to move. Friction between the wind and the water surface affects the movement of the water body in its course

• Gravity: It tends to pull the water down the pile and create gradient variation.

• Coriolis force: This intervenes and causes the water to move to the right in the northern hemisphere and to the left in the southern hemisphere. These large accumulations of water and the flow around them are called Gyres. These produce large circular currents in all the ocean basins.

The secondary forces that influence the currents are:

• Difference in water density: It affect vertical mobility of ocean currents. Denser water tends to sink, while relatively lighter water tends to rise.

• Difference in Salinity: Water with high salinity is denser than water with low salinity and in the same way cold water is denser than warm water.

Long Answer Type Questions :

Q1.In how many categories can tides be classified on the basis of their height and frequency?
Answer:

• Semi-diurnal tide: It is the most common tidal pattern, featuring two high tides and two low tides each day. The successive high or low tides are approximately of the same height.
• Diurnal tide: There is only one high tide and one low tide during each day. The successive high and low tides are approximately of the same height.
• Mixed tide: Tides having variations in height are known as mixed tides. These tides generally occur along the west coast of North America and on many islands of the Pacific Ocean.
• Spring tides: The position of both the sun and the moon in relation to the earth has direct bearing on tide height. When the sun, the moon and the earth are in a straight line, the height of the tide will be higher. These are called spring tides.
• Neap tides: Wlien the sun and moon are at right angles to each other and the forces of the sun and moon tend to counteract one another. The moon’s attraction, though more than twice as strong as the sun’s, is diminished by the counteracting force of the sun’s gravitational pull. These are called neap tides.

Q2.White the characteristics of waves in the oceanic water.
Answer:
Characteristics of waves in the oceanic water are given below:

• The highest and lowest points of a wave are called the crest and trough.
• Wave height is the vertical distance from the bottom of a trough to the top of a crest of a wave.
• Wave amplitude is one-half of the wave height.
• Wave period is merely the time interval between two successive wave crests.
• Wavelength is the horizontal distance between two successive crests.
• Wave speed is the rate at which the wave moves through the water, and is measured in knots.
• Wave frequency is the number of waves passing a given point during a one- second time interval.

Q3.Explain how do heating of solar energy, wind, gravitation and coriolis force affect the ocean currents.
Answer:
Heating by solar energy: Heating by solar energy causes the water to expand, that is why, near the equator the ocean water is about 8 cm higher in level than in the middle latitudes. This causes a very slight gradient and water tends to flow down the slope.

• Wind: Wind blowing on the surface of the ocean pushes the water to move. Friction between the wind and the water surface affects the movement of the water body in its course.
• Gravity: Gravity tends to pull the water down the pile and create gradient variation.
• The Coriolis force: The coriolis intervenes and cause the water to move to the right in the northern hemisphere and to the left in the southern hemisphere.

Q4.Differentiate between warm currents and cold currents.
Answer:

S.no.	Warm currents	Cold currents
1.	They flow from equatorial regions to high latitudes.	They flow from polar region to low latitudes.
2.	Its temperature is higher than the surrounding water.	Its temperature is below than the surrounding water.
3.	It raises the temperature of coastal areas and are observed normally on the east coast of lower and middle latitude.	It reduces the temperature of the coastal area and are observed on the west of continent in lower and middle latitudes.
4.	Winds passing over warm currents absorb a good amount of moisture and bring heavy rainfall on the coastal areas.	Winds passing over cold currents becomes dry and little rainfall on the coaarea.
5.	Warm currents are of great help to navigation because they melt ice bergs.	Cold currents hinder navigation because they create ice bergs.
6.	Warm currents keep the ports open in the polar regions free from ice.	Cold currents make the parts unoperational in lower latitudes as they are ice bound.

SHORT ANSWER TYPE QUESTION:

Q1. Why do we call the earth a Blue Planet?
Answer
The earth is called as a Blue Planet because of abundant supply of water on its surface. Water is a rare commodity in our solar system. There is no water on the sun or anywhere else in the solar system.

Q2. What is a continental margin?
Answer
The continental slope together with the continental shelf is called the continental margin.

Q3. List out the deepest trenches of various oceans.
Answer
There are 57 trenches have been explored so far; of which 32 are in the Pacific Ocean; 19 in the Atlantic Ocean and 6 in the Indian Ocean

Q4.What is a thermocline?
Answer
The boundary region, from where there is a rapid decrease of temperature, is called the thermocline. This layer lies below the first layer and is characterised by rapid decrease in temperature with increasing depth.

Q5. When you move into the ocean what thermal layers would you encounter? Why the temperature varies with depth?
Answer
When we move into the ocean we will encounter three thermal layers.The temperature varies with the depth because the temperature structure of oceans over middle and low latitudes can be described as a three layer system. The first layer is about 500m thick with temperatures ranging between 20° and 25° C. The second layer is 500 -1,000 m thick. The third layer is very cold and extends upto the deep ocean floor

Q6. What is salinity of sea water?
Answer
Salinity is the term used to define the total content of dissolved salts in sea water . It is calculated as the amount of salt (in gm) dissolved in 1,000 gm (1 kg) of seawater. It depend mainly on evaporationand precipitation.

Q7. How are various elements of the hydrological cycle interrelated?
Answer
Water is a cyclic resource. It can be used and re-used. The hydrological cycle, is the circulation of water within the earth’s hydrosphere in different forms i.e. the liquid, solid and the gaseous phases. It also refers to the continuous exchange of water between the oceans, atmosphere, landsurface and subsurface and the organisms. The distribution of water on earth is quite uneven. Many locations have plenty of water while others have very limited quantity. About 71 per cent ofthe planetary water is found in the oceans. The remaining is held as freshwater in glaciers and icecaps, groundwater sources, lakes, soil moisture, atmosphere, streams and within life. Nearly 59 per cent of the water that falls on land returns to the atmosphere through evaporation from over the oceans as well as from other places. The remainder runs-off on the surface, infiltrates into the ground or a part of it becomes glacier

Q8.Examine the factors that influence the temperature distribution of the oceans.
Answer
The factors which affect the distribution of temperature of ocean water are :
(i) Latitude: The temperature of surface water decreases from the equator towards the poles because the amount of insolation decreases poleward.
(ii) Unequal distribution of land and water: The oceans in the northern hemisphere receive more heat due to their contact with larger extent of land than the oceans in the southern hemisphere.
(iii) Prevailing wind: The winds blowing from the land towards the oceans drive warm surface water away form the coast resulting in the upwelling of cold water from below. It results into the longitudinal variation in the temperature. Contrary to this, the onshore winds pile up warm water near the coast and this raises the temperature.
(iv) Ocean currents: Warm ocean currents raise the temperature in cold areas while the cold currents decrease the temperature in warm ocean areas. Gulf stream (warm current) raises the temperature near the eastern coast of North America and the West Coast of Europe while the Labrador current (cold current) lowers the temperature near the north-east coast of North America.

Long Answer Type Questions

Q1.The average temperature of water on oceans floor keeps on falling from equator to poles systematically. Explain.
Answer:
The average temperature of surface water of the- oceans is about 27°C and it gradually decreases from the equator towards the poles. The rate of decrease of temperature with increasing latitude is generally 0.5°C per latitude. The average temperature is around 22°C at 20° latitudes, 14° C at 40° latitudes and 0° C near poles.

The oceans in the northern hemisphere record relatively higher temperature than in the southern hemisphere. The highest temperature is not recorded at the equator but slightly towards north of it.

The average annual temperatures for the northern and southern hemisphere are around 19° C and 16° C respectively. This variation is due to the unequal distribution of land and water in the northern and southern hemispheres.

Q2.Explain about horizontal distribution of salinity.
Answer:
Horizontal distribution of salinity:

• The salinity for normal Open Ocean ranges between 33% and 37%. In the land locked Red Sea records higher salinity due to high evaporation.
• Salinity is, however, very low in Black Sea due to enormous fresh water influx by rivers.
• The average salinity of the Indian Ocean is 35 %.
• The low salinity trend is observed in the Bay of Bengal due to influx of river water.
• On the contrary, the Arabian Sea shows higher salinity due to high evaporation and low influx of fresh water.

Q3.Explain about vertical distribution of salinity.
Answer:
Vertical distribution of salinity

• Salinity changes with depth, but the way it changes depends upon the location of the sea. Salinity at the surface increases by the loss of water to ice or evaporation, or decreased by the input of fresh waters, such as from the rivers.
• Salinity at depth is very much fixed, because there is no way that water is ‘lost’, or the salt is ‘added.’
• There is a marked difference in the salinity between the surface zones and the deep zones of the oceans. The lower salinity water rests above the higher salinity dense water.
• Salinity, generally, increases with depth and there is a distinct zone called the halocline, where salinity increases sharply.
• Other factors being constant, increasing salinity of seawater causes its density to increase. High salinity seawater, generally, sinks below the lower salinity water. This leads to stratification by salinity.

Q4.Explain about vertical distribution of temperature.
Answer:
The temperature structure of oceans over middle and low latitudes can be described as a three-layer system from surface to the bottom.

• The first layer represents the top layer of warm oceanic water and it is about 500 m thick with temperatures ranging between 20° and 25° C. This layer, within the tropical region, is present throughout the year but in mid-latitudes it develops only during summer.
• The second layer called the thermocline layer lies below the first layer and is characterised by rapid decrease in temperature with increasing depth. The thermocline is 500 – 1,000 m thick.
• The third layer is very cold and extends upto the deep ocean floor. In the Arctic and Antarctic circles, the surface water temperatures are close to 0 C and so the temperature change with the depth is very slight.

Q5.Explain the features of the deep sea plains, submarine ridges, ocean deeps and seamount.
Answer:
Abyssal plains (the deep sea plains):

• These are the world’s flattest and smoothest regions.
• About 40% of the oceanic floor is flat.
• It is formed accumulation of sediments on the sea floor.
• Its depth varies from 3000-6000 m.

Submarine ridges:

• Oceanic floors have submarine narrow and elongated ridges.
• They resemble mountain ridges on the earth surface.
• Peak of these ridges may rise above the sea level to form islands.
• Eg-Philippines Ice land is a mid-Atlantic ridge.

Oceanic deeps of submarine trenches:

• Deep narrow steep sided depression is found along the abyssal plain.
• The depth of these trenches may vary from 6,000 to 11,000 m. Example, Marina trenches is the deepest trench in Pacific Ocean.
• Trenches are formed as a result of tectonic forces and normally occur along the marines of Pacific Ocean.
• They occur at the base of the continental slopes and along the island area. Normally associated with volcanoes and strong earthquake.
• There are 32 trenches in Pacific Ocean, 19 in Atlantic Ocean and just 6 in Indian Ocean.

Seamount:

• It is the mount with a pointed submit rising from the sea floor but do not reach the surface of ocean. For example
  • Emperor seamount, an extension of Hawaiian islands in Pacific Ocean
  • The tallest seamount between Soman and New Zealand.
• Seamounts are volcanic in origin and can be 3000 to 4500 m tall.

SHORT ANSWER TYPE QUESTION:

Q1. Which two climatic variables are used by Koeppen for classification of the climate?
Answer
Temperature and precipitation are two climatic variables are used by Koeppen for classification of the climate.

Q2.How is the “genetic” system of classification different from the “empirical one”?
Answer
Empirical classification is based on observed data, particularly on temperature and precipitation. Genetic classification attempts to organise climates according to their causes.

Q3. Which types of climates have very low range of temperature?
Answer
Tropical Humid Climates have very low range of temperature. It exist between Tropic of Cancer and Tropic of Capricorn.

Q4.What type of climatic conditions would prevail if the sun spots increase?
Answer

When the number of sunspots increase, cooler and wetter weather and greater storminess occur.

Q5. Make a comparison of the climatic conditions between the “A” and “B” types of climate.
Answer

“A” Type of Climate	“B” Type of Climate
It belongs to tropical climate.	It belongs to sub-tropical climate.
It exist between Tropic of Cancer and Tropic of Capricorn.	These are found in low or mid latitudes in the area of subtropical high where subsidence and inversion of temperature do not produce rainfall
Annual range of temperature is very low and annual rainfall is high.	Very low rainfall that is not adequate for the growth of plants.
The tropical group is divided into three types, namely (i) Af-Tropical wet climate; (ii) Am – Tropical monsoon climate; (iii) Aw- Tropical wet and dry climate.	Dry climates are divided into steppe or semi-arid climate (BS) and desert climate (BW).

Q6. What type of vegetation would you find in the “C” and “A” type(s) of climate?
Answer
Vegetation in “A” type of climate: The sun being overhead throughout the year and gigh rainfall make the condition appropriate for the growth of plants. It supports rainforests. Tropical evergreen forests with dense canopy cover and large biodiversity are found in Tropical Wet Climate. Deciduous forest and tree-shredded grasslands occur in Tropical Wet and Dry Climate.

Vegetation in “C” type of climate: Warm temperate climates extend from 30° – 50° of latitude mainly on the eastern and western margins of continents. These climates generally have warm summers with mild winters. It is same as tropical forest. The forests have trees, shrubs and bushes. Broadleaf trees provide a continuous and dense canopy in summer and shed their leaves in winter. The shorter trees and shrubs of different heights and grow rapidly in summer and warm spring. Ferns, mosses and other plants which grow quickly in spring but disappear in winter.

Q7.What do you understand by the term “Greenhouse Gases”? Make a list of greenhouse gases.

Answer

A greenhouse is made up of glass. The glass which is transparent to incoming short wave solar
radiation is opaque to outgoing long wave radiation. The glass, therefore, allows in more radiation and prevents the long wave radiation going outside the glass house, causing the temperature inside
the glasshouse structure warmer than outside. Due to the presence of greenhouse gases, the atmosphere is behaving like a greenhouse. The atmosphere also transmits the incoming solar
radiation but absorbs the vast majority of long wave radiation emitted upwards by the earth’s surface. The gases that absorb long wave radiation are called greenhouse gases. The processes that warm the atmosphere are often collectively referred to as the greenhouse effect.

The primary Greenhouse Gases are:
• Carbon dioxide (CO₂)
• Chlorofluorocarbons (CFCs)
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Ozone (O₃).

Some other gases such as nitric oxide (NO) and carbon monoxide (CO) easily react with GHGs and affect their concentration in the atmosphere.

Long Answer Type Questions :

Q1.Explain the major climate categories by Koeppen.
Answer:
The first level recognises six major climatic types with each group being designated by a capital letter. These major climate categories have the following broad characteristics:

•  Tropical moist climates: These are very warm climates found in the tropics that experience high quantities of precipitation. The primary distinguishing characteristic of these climates is that all months have average temperatures above 18 C (64 F).
• Dry climates: These are climates that experience little precipitation during most of the year. Further, potential losses of water from evaporation and transpiration greatly exceed atmospheric input.
• Moist mid-latitude climates with mild winters: In these climates, summer temperatures are warm to hot and winters are mild. The primary distinguishing characteristic of these climates is that the coldest month has an average temperature between 18 C (64 F) and -3 C (27 F).
• Moist mid-latitude climates with cold winters: In these climates, summer temperatures are warm and winters are cold. The primary distinguishing characteristic of these climates is the average temperature of warmest month exceeds 10 C (50 F), and average temperature of coldest is below -3 C (27 F).
• Polar climates: These climates have very cold winters and summers, with no real summer season. The primary distinguishing characteristic of these climates is the warmest month has an average temperature below 10 C (50 F).
• Highland climates: These are climates that are strongly influenced by the effects of altitude. As a result, the climate of such locations is rather different from places with low elevations at similar latitudes.

Q2.Explain the climatic changes that has taken place since ancient times. Also explain its causes.
Answer:
The type of climate we experience now might be prevailing over the last 10,000 years with minor and occasionally wide fluctuations. The planet earth has witnessed many variations in climate since the beginning. Geological records show alteration of glacial and inter-glacial periods. The sediment deposits in glacial lakes also reveal the occurrence of warm and cold periods. The rings in the trees provide clues about wet and dry periods. Historical records describe the diversities in climate. All these evidences indicate that change in climate is a natural and continuous process. Archaeological findings show that the Rajasthan desert experienced wet and cool climate around 8,000 B.C. During the Pleistocene epoch, glacial and inter-glacial periods occurred, the last major peak glacial period was about 18,000 years ago. The present inter-glacial period started 10,000 years ago. Variability in climate occurs all the time. The nineties decade of the last century witnessed extreme weather events. The 1990s recorded the warmest temperature of the century and some of the worst floods around the world. Europe witnessed “Little Ice Age” from 1550 to about 1850. From about 1885¬1940 world temperature showed an upward trend. After 1940, the rate of increase in temperature slowed down.
Causes of Climate Change: The causes for climate change can be grouped into astronomical and terrestrial causes.

1. The astronomical causes: These are the changes in solar output associated with sunspot activities. Sunspots are dark and cooler patches on the sun which increase and decrease in a cyclical manner. According to some meteorologists, when the number of sunspots increase, cooler and wetter weather and greater storminess occur. A decrease in sunspot numbers is associated with warm and drier conditions.

2. Volcanism: It is considered as another cause for climate change. Volcanic eruption throws up lots of aerosols into the atmosphere. These aerosols remain in the atmosphere for a considerable period of time reducing the sun’s radiation reaching the Earth’s surface. After the recent Pinatoba and El Cion volcanic eruptions, the average temperature of the earth fell to some extent for some years.

3. Greenhouse gases: The most important anthropogenic effect on the climate is the increasing trend in the concentration of greenhouse gases in the atmosphere which is likely to cause global warming.

Q3.Explain about Polar climate (E).
Answer:
Polar Climates (E) exist poleward beyond 70 latitude. Polar climates consist of two types:

1. Tundra (ET);
2. Ice Cap (EF).

1. Tundra Climate (ET): The tundra climate (ET) is so called after the types of vegetation, like low growing mosses, lichens and flowering plants. This is the region of permafrost where the sub soil is permanently frozen. The short growing season and water logging support only low growing plants. During summer, the tundra regions have very long duration of day light.

2. Ice Cap Climate (EF): The ice cap climate (EF) occurs over interior Greenland and Antarctica. Even in summer, the temperature is below freezing point. This area receives very little precipitation. The snow and ice get accumulated and the mounting pressure causes the deformation of the ice sheets and they break. They move as icebergs that float in the Arctic and Antarctic waters. Plateau Station, Antarctica ,79 S, portray this climate.

Q4.Explain about Cold snow forest climates (D).
Answer:
Cold Snow Forest Climates (D) occur in the large continental area in the northern hemisphere between 40 -70 north latitudes in Europe, Asia and North America. Cold snow forest climates are divided into two types:

1. Df- cold climate with humid winter;
2. Dw- cold climate with dry winter.

The severity of winter is more pronounced in higher latitudes.
1. Cold climate with humid winters (Df): Cold climate with humid winter occurs poleward of marine west coast climate and mid latitude steppe. The winters are cold and snowy. The frost free season is short. The annual ranges of temperature are large. The weather changes are abrupt and short. Poleward, the winters are more severe.

2.Cold climate with dry winters (Dw): Cold climate with dry winter occurs mainly over Northeastern Asia. The development of pronounced winter anti cyclone and its weakening in summer sets in monsoon like reversal of wind in this region. Poleward summer temperatures are lower and winter temperatures are extremely low with many locations experiencing below freezing point temperatures for up to seven months in a year. Precipitation occurs in summer. The annual precipitation is low from 12-15 cm.

Q5.Write a detailed note on Tropical monsoon climate (Am).
Answer:
Tropical monsoon climate, occasionally also known as a tropical wet climate or tropical monsoon and trade-wind littoral climatein climate classification, is a relatively rare type of climate that corresponds to the Koppen climate classification category “Am”.

Tropical monsoon climates have monthly mean temperatures above 18 C in every month of the year and feature wet and dry seasons, as Tropical savanna climates do. Unlike tropical savanna climates however, a tropical monsoon climate’s driest month sees less than 60 mm of precipitation but more than (100 [total annual precipitation [mm}/25]). Also, a tropical monsoon climate tends to see less variance in temperatures during the course of the year than a tropical savanna climate. This climate has a driest month which nearly always occurs at or soon after the “winter” solstice for that side of the equator. Tropical monsoon climates are most commonly found in South and Central America. However, there are sections of South Asia, Southeastsia, Africa (particularly West and Central Africa), the Caribbean, and North America that also features this climate.