Geography: UPSC Previous Year Questions (Prelims)

Explanation

Statement 1 is correct: Paddy fields are typically flooded, creating anaerobic (oxygen-deprived) conditions. Soil saturation in wetland rice fields restricts oxygen transport, creating anaerobic conditions due to submergence. This environment supports the activity of methanogenic bacteria, which produce methane (CH₄), a potent greenhouse gas. Rice cultivation is a significant source of methane emissions globally.

Statement 2 is correct: Nitrogen-based fertilizers, which enhance crop yield, stimulate soil microbes to convert nitrogen into nitrous oxide (N₂O), another potent greenhouse gas. Microbial processes like nitrification and denitrification in the soil release nitrous oxide, especially in poorly drained, waterlogged soils. Nitrous oxide has a global warming potential 265 times greater than CO₂ over 100 years.

Explanation

Energy crops, also called agroenergy or bioenergy crops, are cultivated specifically to generate biomass for renewable energy production. These crops can thrive on degraded, waste, saline, or waterlogged lands. In addition to providing a sustainable energy source, energy crops contribute to reducing greenhouse gas emissions. They also play a role in enhancing water quality and supporting wildlife habitats.

Option (a) is incorrect: Jatropha is primarily cultivated for biodiesel, as its seeds contain oil that can be converted to biodiesel. It is not used for ethanol production.

Option (b) is correct: Maize (corn) is a major crop used for ethanol production. It is rich in starch, which is fermented by yeast into ethanol.India is expanding maize-based ethanol production as part of the Ethanol Blending Program (EBP) to reduce petrol imports.

Option (c) is incorrect: Pongamia (Indian beech) is mainly used for biodiesel production due to the oil content in its seeds. It is not used for ethanol production.

Option (d) is incorrect: Sunflower, with very low sugar content, is primarily grown for edible oil production. It is not a significant crop for ethanol production.

Explanation

Statement 1 is correct: National Parks are established under the Wildlife (Protection) Act, 1972. The State Government issues a notification specifying the precise limits of the area designated as a National Park. Any alteration of these boundaries requires a resolution passed by the State Legislature.These areas receive strict protection, and activities like hunting, poaching, and deforestation are strictly prohibited. India’s first National Park Jim Corbett National Park was established under this Act.

Statement 2 is incorrect: Biosphere Reserves aim to conserve entire ecosystems rather than focusing on specific species. They are designated to promote the conservation of biodiversity, foster sustainable development, and support research and education. These reserves include core, buffer, and transition zones to balance conservation with sustainable use.

Statement 3 is correct: Wildlife Sanctuaries in India allow certain human activities, such as grazing or resource collection, under regulated conditions. The Chief Wildlife Warden may grant permissions for such activities, ensuring they do not adversely affect wildlife. This flexibility distinguishes Wildlife Sanctuaries from National Parks, where stricter protections are enforced.

Explanation

The given characteristics describe a tropical or sub-tropical region with the following conditions:

Hot and humid climate with annual rainfall of 200 cm suggests a climate suited for tropical crops that thrive in moist conditions. Hill slopes up to an altitude of 1100 metres indicate a location in lower to mid-altitudes (common in regions like the Western Ghats or Eastern Ghats). The annual temperature range of 15°C to 30°C also suggests moderate temperatures, which is typical of many tropical crops. Given these characteristics, pepper is the most likely crop to thrive in this region for the following reasons:

Pepper(Piper nigrum) thrives in tropical regions with high humidity, annual rainfall around 200 cm, and moderate temperatures. It is commonly cultivated on hill slopes, especially in regions like Kerala, Karnataka, and Tamil Nadu, where these conditions are prevalent.

Option (a) is incorrect: Mustard (Brassica spp.) thrives in cool and dry climates, typically grown in temperatures between 10°C and 25°C. It requires low to moderate rainfall (40-60 cm), as excessive moisture can damage the crop. It is grown in North India (Punjab, Haryana, Rajasthan, Madhya Pradesh, Uttar Pradesh) in Rabi season (winter).

Option (b) is incorrect: Cotton (Gossypium spp.) requires a warm climate with temperatures between 21°C and 30°C. It prefers moderate rainfall (50-100 cm); excessive rainfall (above 200 cm) can harm the crop. It is grown in black soil regions of Maharashtra, Gujarat, Karnataka, Telangana, and Madhya Pradesh.

Option (d) is incorrect: Virginia tobacco (Nicotiana tabacum) requires moderate temperatures (20°C-30°C) and low rainfall (50-100 cm). Excessive humidity and rainfall hamper tobacco growth. It is grown in Andhra Pradesh, Karnataka, and Gujarat but in regions with controlled irrigation.

Explanation

Pair 1 is incorrectly matched: Jharkhand is not the primary source of copper in India. The Singhbhum district of Jharkhand has some copper reserves but Madhya Pradesh (Malanjkhand) and Rajasthan (Khetri) are the largest producers, contributing ~90% of India’s copper.

Pair 2 is correctly matched: Odisha (formerly Orissa) is the largest producer of nickel in India, with major deposits in the Sukinda Valley.

Pair 3 is incorrectly matched: Kerala is not a significant source of tungsten in India. The distribution of tungsten re-sources in India is as follows:

Karnataka: Approximately 41% Rajasthan: Around 27% Andhra Pradesh: About 17% Maharashtra: Approximately 11%

Explanation

Pair 1 is correctly matched: Bhitarkanika National Park in Odisha is a vital estuarine ecosystem and a key habitat for saltwater crocodiles, the world’s largest living reptiles. It hosts mangrove forests, estuarine habitats, and numerous bird species.

Pair 2 is correctly matched: Desert National Park in Rajasthan is one of the last remaining strongholds of the Great Indian Bustard. It is critically endangered and among the heaviest flying birds. The park consists of sand dunes, grasslands, and rocky landscapes, providing an ideal habitat for this rare bird.

Pair 3 is incorrectly matched: Eravikulam National Park in Kerala is renowned for the Nilgiri Tahr, an endangered mountain goat, not the Hoolock Gibbon. Hoolock Gibbons are native to Northeast India, primarily in Arunachal Pradesh and Assam.

Explanation

Tropical Moist Deciduous Forests cover the largest area in India, found across Central India, the Western Ghats, the Eastern Ghats, and the Himalayan foothills. They thrive in 1,000-2,000 mm annual rainfall zones and experience a distinct dry sea-son, leading to leaf shedding. Dominant tree species are Sal (Shorea robusta) in the north and Teak (Tectona grandis) in the south. It covers about 37% of India’s total forest area.

Explanation

The Luni River, also known as the Sagarmati River, originating from the Aravalli Hills near Ajmer, Rajasthan. It is the largest river in the Thar Desert and flows southwest through Rajasthan and Gujarat. Unlike major rivers that drain into the sea, Luni is endorheic. It does not flow into the Gulf of Khambhat or the Gulf of Kutch, nor does it cross into Pakistan to merge with the Indus system. Due to high salinity and arid conditions, it eventually disappears into the marshy lands of the Rann of Kutch.

Explanation

Option (d) is correct: Himachal Pradesh is a mountainous state located in the western Himalayas, and several significant rivers flow through it. These rivers originate in the Himalayas and are vital for irrigation, hydroelectric projects, and other water needs in northern India. Beas River originates from Beas Kund near Rohtang Pass in Himachal Pradesh. It flows entirely within Himachal Pradesh before entering Punjab. Chenab River originates near Baralacha Pass in the Lahaul-Spiti region of Himachal Pradesh. After originating in Himachal, it flows into Jammu & Kashmir and later into Pakistan. Ravi River originates near Bara Banghal in the Kangra district of Himachal Pradesh. It flows through Chamba district and then into Jammu & Kashmir before crossing into Pakistan. Sutlej River originates from Mansarovar Lake near Mount Kailash in Tibet. It enters Himachal Pradesh through the Shipki La Pass and flows through Kinnaur before entering Punjab. The Bhakra Nangal Dam is built on this river. Yamuna River originates near Yamunotri Glacier in Uttarakhand.The river forms the eastern boundary of Himachal Pradesh and flows through districts like Sirmaur and Paonta Sahib before entering Haryana. Fig: Map depicting Indus and its tributaries.

Explanation

Exp:

Option (a) is incorrect: Magnesium is not responsible for the red color. It affects soil fertility but not its hue.

Option (b) is incorrect: Humus contributes to dark brown or black soils, not red soils. Red soils are low in organic content.

Option (c) is correct: The red color of red soil is primarily due to the presence of ferric oxides (iron oxides) in its composition. Red soils are formed from the weathering of ancient crystalline and metamorphic rocks, particularly in regions with a hot and dry climate. Iron-bearing minerals in these rocks oxidize over time, forming ferric oxides that impart the red color. Its colour varies from red to brown, depending on the intensity of oxidation and hydration. They are generally low in nitrogen, phos-phorous, and organic matter (humus) but rich in iron. They are found extensively in peninsular India, including parts of Tamil Nadu, Karnataka, Andhra Pradesh, Odisha, Madhya Pradesh, and Maharashtra. Common in areas with low rainfall where leaching is minimal, allowing ferric oxides to accumulate.

Option (d) is incorrect: Phosphates improve soil fertility but do not influence soil color significantly.