Geography: UPSC Previous Year Questions (Prelims)

Explanation

Water is an indispensable resource for various indus-trial processes. In India, different industries use water in varying amounts, but the thermal power sector stands out as the high-est consumer due to its extensive cooling and steam generation requirements. While engineering, paper and pulp, and textiles industries do require water for various operations such as manufacturing, cleaning, and processing, their water consumption is comparatively much lower than that of thermal power plants.

Explanation

Contour bunding is a soil conservation technique primarily employed in hilly or sloping terrains to combat soil erosion and enhance water retention. This method involves constructing embankments, or "bunds," along the natural contour lines of the landscape. These bunds act as barriers that slow down water runoff, promote water infiltration and reduce the loss of topsoil. Options (a), (b) and (c) are incorrect:

Contour bunding is not suitable for desert margins or areas prone to strong wind action. Wind erosion is better controlled by techniques like windbreaks or shelterbelts, not contour bunding. In low-lying flat plains prone to flooding contour bunding is less effective. Flood management and soil conservation in these areas often involves levees, dykes, or drainage systems rather than contour bunds. Contour bunding is not specifically designed for scrublands prone to weed growth. Weed control requires different management practices, such as mechanical or chemical weeding methods.

Explanation

The nitrogen cycle is a crucial process that maintains the soil fertility necessary for plant growth.

Statement 1 is correct: Animals excrete urea through urine containing nitrogen. When this urea is deposited onto the soil, soil microorganisms break it down through a process called mineralization, converting it into ammonium (NH₄ +), which can readily absorbed by plants.

Statement 2 is incorrect: While the burning of coal releases nitrogen oxides (NOx) into the atmosphere, it does not directly add nitrogen to the soil. Instead, the pollutants can contribute to air pollution and acid rain, which may eventually affect soil quality but not in a beneficial way for nitrogen enrichment of soil.

Statement 3 is correct: The death and decomposition of vegetation naturally adds nitrogen to the soil. When plants die, their organic matter decomposes due to microbial activity. During de-composition, nitrogen is released in the form of ammonium and nitrates, which then enrich the soil. This recycling of nutrients is a natural and critical component of the nitrogen cycle.

Explanation

Pair 1 is correctly matched: Tamang, Limbu, Bhutia, Khas, Lepchas are important tribal communities of Sikkim.

Pair 2 is incorrectly matched: Karbi is a tribal community from Karbi Anglong of Assam, not Himachal Pradesh. Other important tribes from the state include Bodo, Kachari, Miri, Mishimi, Rabha.

Pair 3 is correctly matched: The Dongaria Kondh is a particularly vulnerable tribal group found in the Niyamgiri Hills of Odisha. They are known for their unique cultural practices and traditional agriculture.

Pair 4 is incorrectly matched: The Bonda tribe is one of the oldest and most primitive tribes in India, residing in the hilly regions of the Malkangiri district in southwestern Odisha, not in Tamil Nadu.

Explanation

The Narmada River is unique among India’s major peninsular rivers due to its westward flow into the Arabian Sea, contrasting with the predominantly eastward flow of other large rivers in the region.

Statement 1 is correct: The Narmada River flows through a linear rift valley which is a geological depression created by the subsidence of the Earth’s crust. It is flanked by the Vindhya Range to the north and the Satpura Range to the south. This rift valley naturally channels the river westward, distinguishing it from most other peninsular rivers that flow eastward.

Statement 2 is incorrect: Though the Narmada does flow between the Vindhya and Satpura ranges but it not the cause of its westward flow. The ranges themselves are remnants of older folded mountains.

Statement 3 is incorrect: While most rivers in the Indian peninsula flow eastward towards the Bay of Bengal. This is due to the region’s natural slope to the west from Central India. But the Narmada River’s westward course is dictated by its unique geological setting within a rift valley.

Explanation

National Parks in India are biodiversity hotspots, often intertwined with rivers that sustain their ecosystems.

Pair 1 is incorrectly matched: Corbett National Park, located in Uttarakhand, is traversed by the Ramganga River, not the Ganga. The Ramganga is a significant tributary within the park, supporting its rich biodiversity.

Pair 2 is incorrectly matched: The Kaziranga National Park is circumscribed by the Brahmaputra River, which forms the northern and eastern boundaries, and the Mora Diphlu, which forms the southern boundary. The Manas River flows through the Manas National Park.

Pair 3 is incorrectly matched: Silent Valley National Park is located in Kerala. It is drained by the Kunthipuzha River, a tributary of the Bharathapuzha River. The Kaveri River flows through Karnataka and Tamil Nadu, not Kerala.

Explanation

Pair 1 is correctly matched: Nokrek Biosphere Re-serve is located in the Garo Hills district of Meghalaya. The biosphere reserve’s name comes from Nokrek Hill, the highest peak of the Garo Hills. It was designated a UNESCO biosphere reserve in 2009 and is home to the red panda and a rich variety of flora and fauna. The reserve is also a significant part of the Western Meghalaya Elephant Landscape and contains the Nokrek National Park.

Pair 2 is incorrectly matched: The Loktak Lake is a freshwater lake in Manipur and is the largest freshwater lake in Northeast India. It is not located in the Barail Range, which is a mountain range in Assam and Nagaland. It is well-known for the phumdis that float above it. Keibul Lamjao National Park, the only floating national park in the world is located in this lake.

Pair 3 is incorrectly matched:: Namdapha National Park is situated in the Changlang district of Arunachal Pradesh. It is part of the Patkai Range, not the Dafla Hills. The Noa Dihing River runs east to west through the national park. The Dafla Hills are located on the Arunachal Pradesh-Assam border, near Pakke Wildlife Sanctuary.

Explanation

Option (b) is correct:

Atlas Mountain: The Maghreb, often referred to as Northwest Africa, the Greater Maghreb, and historically as the Barbary Coast, is where the Atlas Mountains is situated. The Atlas Mountains divide the Sahara Desert from the Mediterranean and Atlantic coasts. The highest point of this mountain range, Toubkal (4167 m), is found in Morocco. The mountains are found in Algeria and Tunisia in addition to Morocco. The Atlas Mountains are home to populations of Berber people.

Option (a), (c) and (d) are incorrect:

Abyssinian Plateau: The Ethiopian Plateau is also referred to as Altipiano Etiopico, Amhara Plateau, Ethiopian Massif, and Ethiopian Plateau. The Abyssinian Plateau was formerly known as Ethiopia, hence the name. The Blue Nile, which emerges from Lake Tana, is the most notable river to cross the plateau. Okavango Basin: The Okavango Basin is situated in southwest Africa comprising Botswana, Namibia, Zimbabwe, Angola, and other countries. Whilst, Patagonia refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. Guiana Highlands: In South America, the Guiana Highlands are situated in the south of the Orinoco River and north of the Amazon River. Parts of Venezuela, the Guianas, Brazil, and Colombia are included in the Guiana Highlands. Mount Roraima, located in the Guiana Highlands, has the highest elevation (2772 m).

Explanation

In the troposphere (near earth surface), temperature usually decreases as altitude rises. This is called the lapse rate. On average, the temperature drops by 1°C for every 165 meters of height. This equals about 6.5°C for every kilometer.

Statement 1 is correct: The Earth’s surface absorbs solar radiation and then re-radiates it as heat. The air in contact with the surface warms up and transfers heat to the layers above through conduction, convection, and radiation. Since the primary heat source is the Earth’s surface, higher altitudes receive less heat, leading to a drop in temperature.

Statement 2 is incorrect: Moisture content (water vapor) which accounts for around 1% of air varies greatly in the troposphere, decreases significantly with altitude, as most water vapor is found near the Earth’s surface. The upper atmosphere is drier, not more moist.

Statement 3 is correct: As altitude increases, air pressure and density decrease. Less dense air holds less heat, contributing to a decrease in temperature with height.

Explanation

The Tropical Savannah climate is characterized by a definite dry and wet season. This climate type is found in regions like parts of Africa, South America, and Australia. The distinguishing feature is the seasonal variation between a wet season (characterized by heavy rainfall) and a dry season (with very little or no rainfall).