ACADEMIC YEAR 2020-21 REVISION WORK CLASS - X GEOGRAPHY

Question 1.

(a). Mention important features of the Indian . Ans. 1. Seasonal 2. Erratic and Unpredictable 3. Unevenly distributed. 4. Mainly orographic in nature. 5. It affects the economy.Some of the rain occurs due to tropical depressions.

(b). What are the causes of Winter rain? Ans. 1. In , the north-east monsoon winds pick up moisture from the Bay of and bring rain. 2. The cause of the rain in all the northern states are the Western disturbances that originate in the Mediterranean Sea.

(c). State the benefits that are derived from the local winds that blow in summer in the following states - i. ii. West Bengal Ans. i. Kerala - Mango showers are good for tea, and mangoes. ii. West Bengal - Kalbaisakhi is good for rice, jute & tea.

(d). Name two types of cyclonic systems that affect and two areas that receive rainfall from these systems. Ans. (i) Western Disturbances : During winter there is an inflow of low pressure depressions called Western Disturbances in North West India. These originate in the Mediterannean Sea and enter India after crossing Iraq, Afghanistan and Pakistan. They intensify over North West India and move eastward causing rain in Punjab, Haryana and Western Uttar Pradesh.

(ii). Tropical Cyclones : During the summer, the whole east coast of India comes under the influence of tropical depressions that are low pressure systems originating at the head of Bay of Bengal.

Give reasons for the following:

(e). Chennai has a lower annual range of temperature than Lucknow.

Ans. Chennai experiences an equable or oceanic climate because it has the influence of the sea, while Lucknow lies in the interior and experiences the continental climate/extreme climate. Hence the annual range of temperature is more in Lucknow than in Chennai.

(f). Shillong gets less than 200 cm of rainfall in the year while Cherrapunji receives more than 1250 cm of rainfall. Ans. Shillong is situated on the leeward side of the Khasi Hills, whereas Cherrapunji is on the Windward side of the same mountain. Cherrapunji gets full force of the South-west Monsoon of the Bay of Bengal current and Shillong being on the rain shadow side gets less rain.

(g). Thar desert gets very little rain. Ans. Thar gets very little rain as it lies on the leeward side of the Aravalli range. This range is parallel to the South-West Monsoon winds. Therefore, the Aravali does not help in bringing rain.

(h). The Himalayas are called the perfect climatic divide. Explain their two-fold functions in this regard. Ans. The Himalayas are called the perfect climatic divide as they divide both sides into two different climatic zones. The two-fold functions of the Himalayas are - a. The Himalayas act as a shield to protect the subcontinent from the bitter cold winds of Central Asia. b. They also act as a barrier for the rain-bearing winds.

(i). West Coastal Plains receive more rainfall than the Eastern Coastal Plains. Ans. Western side of Western Ghats receives direct rain from the South-West Monsoon, whereas Eastern Coastal Plains lie in the rain-shadow/leeward side of Western Ghats. Hence, receives very little rainfall.

(j). Study the climate data given below and answer the questions that follow:

Month Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

Temp (℃) 12.0 25.5 26.3 27.1 30.0 36.2 36.0 35.9 30.3 28.4 21.0 16.6

Rainfall 1.5 0.1 0.0 1.4 1.1 21.0 25.3 27.2 24.0 9.4 1.5 0.4 (cm)

(i). What is the annual range of temperature of the station? (ii). What is the total annual rainfall experienced by the station? (iii). Why should it be correct to presume that the station lies in the interior and not on the coast? Ans. (i). 24.2℃ (ii). 112.9 cms

(iii). It is located in the interior because the annual range is high/experiences continental type of climate i.e. very hot in summer and very cold in winter.

Question 2.

(a). Why is the soil in the valley of the river Godavari different from that found in the valley of the river Yamuna? Ans. Soil found near the valley of the River Godavari is black soil. Soil found near the valley of the River Yamuna is alluvial soil. Black soil is formed due to disintegration of basalt. It is volcanic in origin. It is formed in the place where it is found (in situ), whereas alluvial soils are formed by the denudation of different types of rocks ad the deposition of sediments by rivers.

(b). Name the type of soil found on the summits of the Eastern Ghats. Ans. Laterite soil is the soil found on the summits of the Eastern Ghats.

(c). (i). Which soil do you associate with the Deccan Trap? Ans. The soil that is associated with the Deccan Trap is black soil/ regur soil/ volcanic soil/ lava soil. (ii) State one advantage of this soil. Ans. One advantage of this soil is that it is fine grained and retains moisture / It is rich in ​ lime, iron, potash, alumina, calcium / It does not undergo leaching.

(d). What is laterite soil? Ans. Laterite soils are those formed under alternating wet and dry spells. They are composed of a mixture of hydrated oxides of aluminum and iron. They are poor in nitrogen, potash, lime. They are low in fertility but respond favourably to manuring and leaching of soil of its nutrients.

(e). What is the meaning of leached soil? Ans. It is the process by which soluble substances such as organic and mineral salts are washed out of the layer of a soil into a lower layer by percolating rainwater.

(f). Give a single word for each of the following: (i). The loose rock material, together with humus, forms the uppermost layer of the earth's crust and serves as a source of food and moisture for plants. (ii). The process of percolation by which valuable mineral nutrients are washed down from the top layer of the soil only to deposit them in the lower layers, thereby making the topsoil infertile. Ans. (i) Soil/Topsoil. (ii) Leaching.

(g). State three methods of soil conservation. Ans. The three methods of soil conservation are — ● Contour bunding

● Planting of more trees ● Overgrazing to be stopped.

(h). With reference to red soil in India: (i) Name two states, where it is found. (ii) State two disadvantages of this soil. Ans. (i). It is found in Tamil Nadu / / Odisha / Andhra Pradesh Telangana / Madhya Pradesh / Goa. (ii) The disadvantages of this soil are: ● It is poor in humus, nitrogen, lime, and phosphorus. ● Not retentive of moisture.

(i). State difference between Sheet Erosion & Gully Erosion. Ans.

Sheet Erosion Gully Erosion

When top soil gets eroded from very large Gully Erosion occurs when running water areas due to fast flowing rivers, it is called etches out deep rivers creating a badland Sheet Erosion. topography in an otherwise normal landscape.

(j) Give a geographic reason for each of the following: (i) Alluvial soil is extremely fertile. (ii) Need for Soil conservation. (iii) Reafforestation should be practised extensively. Ans. (i). ● As it contains minerals like lime, potash, iron and humus, it is loamy, it has sufficient depth, it is renewed annually / replenished by flood. ● It is transported soil which brings along lots of minerals / Alluvium / silt . it is non-porous / moisture or water retentive if all the minerals are present - (any one point). ● As soil supports all plant life, to increase our agricultural output, Various methods / Efforts made by man to check soil erosion and retain the fertility of the soil.

(ii) ● Reclamation of Ravine lands / badland ● India is Agricultural country.

(iii) ● As it helps prevent soil erosion, it holds the soil together. ● It helps maintain the ecological balance. ● It checks global warming . It reduces the severity of drought.

● It maintains the water table.

Question 3.

(a). What are the two main causes in the shrinkage in forest areas in India? Ans. The main reasons for the shrinkage in forest is mainly due to growth in population which leads increased demands for agricultural land, establishment of industries and new townships.

(b). State in what way the following trees and Following trees and plants are useful to man? i. Pine ii. Tea iii. Cinchona iv. Bamboo Ans. (i). Pine is useful in making boxes for packing. (ii). Teak provides wood for shipbuilding, house construction and furniture ​ ​ (iii). Cinchona bark is used for media purposes. (iv). Bamboo is also used to construct houses, bridges.

(c). Why are forests grown in and around the iron and steel cities? Ans. Forests are grown in and around the steel cities to reduce pollution and since they also provide basic raw materials.

(d). Briefly give the characteristics of the forests that flourish in the delta of the river Ganga. Name two typical trees found there. ​ ​ Ans. The forests that can be noticed here are the Tidal/Mangrove forests. Following are its chief characteristics : ● They are the trees that grow under water and are related to the occurrence of tides. ● They can be seen in abundance and its wood is hard. Gorjan and hintal are two typical examples of tidal forests

(e). Name the economically most important vegetation belt of India. Ans. The most important vegetation belt of India is Tropical Monsoon Forests/Monsoon Forests/ Deciduous Monsoon Forests.

(f). Name one region in India for each of the following: (i) Tropical evergreen forests (ii) Thorn and scrub forest. Ans. (i) Regions where Tropical Evergreen Forests are seen - The western parts of Maharashtra, Karnataka, Kerala, the eastern Himalayas, windward side of Western Ghats, North-East India, Andaman, Nicobar Islands, Terai region.

(ii) Regions where Thorn and Scrub Forests are seen - Drier parts of Punjab, Gujarat, Rajasthan, dry parts of Deccan plateau in Karnataka, and Andhra Pradesh, Telangana.

(g). Write three main characteristics of the Deciduous Monsoon Forests. Ans. ● The Deciduous Monsoon Forests shed their leaves for some 6 to 8 weeks in the hot weather. ● They are 30 to 45 metres tall and provide useful hardwood and broad leaves. ● They are found in pure stands.

(h) Name the natural vegetation found in the following regions - (i) The western slopes of the Western Ghats. (ii) The Nilgiris. (iii) Western Rajasthan Ans. Natural Vegetation found on - (i). Western slopes of the western ghats - Tropical Evergreen forests/Rainforests. (ii). The Nilgiris - Mountain forests/Deciduous forests/Mixed forests/Coniferous forests. (iii). Western Rajasthan - Dry forests/Thorn and Scrub.

(i). How do forests - (i) Have a favourable effect on the climate of the region? (ii) Act as a flood control measure? Ans. (i). ● Forests control humidity, lower the temperature and can be responsible for rain. ● They regulate effectively climate, global warming, greenhouse gases, all elements of weather and climate. (ii). The roots of the trees check the speed of running water which then does not overflow its banks and also because the roots take in some of the water. Absorb or increase percolation or reduce surface runoff.

(j) (i). Mention three reasons why forests must be conserved. (ii). Differentiate between Afforestation and Deforestation. (iii). Mention reasons for the conservation and development of forests in India. Ans. (i) The conservation of forests is very necessary because - ● Trees help to control pollution. ● Provide timber for domestic and commercial uses. ● Natural habitat for wildlife.

(ii). Afforestation Deforestation

Planting of trees over a large area / grow Cutting of trees over a large area. more trees.

(iii). ● Reckless cutting of trees must be stopped. ● The productivity of forests must be improved through silviculture. ● Forests must be protected from fires. ● Proper legislation and its implementation. ● Using alternative sources of energy. ● Prevention of overgrazing. ● Shifting Cultivation needs to be controlled.