Geography: UPSC Previous Year Questions (Prelims)

Explanation

According to World Bank data, among the given South Asian countries, India has the highest population density. In 2008, its density was approximately 406. In comparison, Sri Lanka has population density roughly around 329, Pakistan about 246, and Nepal is around 208 persons per square kilometer.

Explanation

Amarkantak, a significant geographical landmark in India, serves as the source for two major rivers that exhibit contrasting hydrological patterns. The Narmada River originates from the Amarkantak Plateau in Madhya Pradesh. It flows westward for 1,312 km, forming a natural divide between North and South India before emptying into the Arabian Sea via the Gulf of Khambhat. Its basin is elongated, with hilly upper reaches and fertile lower plains ideal for cultivation. The Son River is a major southern tributary of the Ganga, also originates near Amarkantak in Chhattisgarh. It initially flows north-northwest through Madhya Pradesh before turning eastward, cutting through the Kaimur Range and running parallel to the Kaimur Hills. It then flows through Uttar Pradesh, Jharkhand, and Bihar, eventually joining the Ganga near Patna. Fig: Map showing routes of Narmada and Son after originating near Amarkantak

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

Badrinath (Uttarakhand) is associated with the origin of the Alaknanda River, which later joins the Ganga system, but it does not give rise to two rivers flowing in opposite directions. Mahabaleshwar (Maharashtra) is the origin of the Krishna River, which flows towards the Bay of Bengal, but no significant river flows northward from here. Nasik (Maharashtra) is located on the banks of the Godavari River, which flows eastward, but there is no major northward-flowing river originating from here.

Explanation

Statement 1 is incorrect: India possesses significant reserves of thorium, particularly in the southern parts of the country. Major Thorium Deposit states are: Andhra Pradesh, Tamil Nadu, Odisha, Kerala, Gujarat, West Bengal and Jharkhand.

Statement 2 is incorrect: Kerala’s monazite sands, particularly along the coastal regions of Kollam and Palakkad, are among the richest for thorium in the world. These sands contain approximately 1.9 million tonnes of monazite, with high concentrations of thorium (up to 10%) and rare earth elements (55-60%).

Explanation

Statement 1 is incorrect: While Kerala is renowned for its numerous west-flowing rivers that drain directly into the Arabian Sea, it is important to note that the state also possesses a few significant east-flowing rivers. The Kabini, Bhavani, and Pambar rivers, for instance, contribute to the eastward flow of water, ultimately merging with the larger Kaveri River system. These rivers flow eastward into neighboring states and ultimately merge with the Kaveri River. Kabini flows into Karnataka, while Bhavani and Pambar enter Tamil Nadu. They play a significant role in inter-state water systems and biodiversity.

Statement 2 is incorrect: Madhya Pradesh, a state characterized by diverse geographical features, is home to a network of rivers flowing westward. The Narmada, Tapi, and Mahi rivers are prominent examples of this westward drainage pattern, ultimately finding their way to the Arabian Sea.

Explanation

Biodiversity hotspots are regions with exceptional levels of plant and animal endemism that are under significant threat. Options 1 and 2 are correct: Among the given regions, the Eastern Himalayas, encompassing parts of Nepal, Bhutan, In-dia, and China, and the Eastern Mediterranean Region qualify as biodiversity hotspots. These regions harbour a remarkable diversity of life, including numerous species found nowhere else on Earth. However, threats like deforestation, habitat loss, and climate change pose significant risks to this precious ecosystem. The Eastern Himalayas region supports iconic species like the Bengal tiger, Asian elephant, red panda, and greater one-horned rhinoceros. The Eastern Himalayas’ rich biodiversity arises from its unique geography at the intersection of three biogeographical realms: Indo-Malayan, Palaearctic, and Sino-Japanese. The Eastern Mediterranean is part of the larger Mediterranean Basin biodiversity hotspot, one of the richest and most threatened regions globally. The region also supports diverse wildlife, including migratory birds, reptiles like geckos and chameleons, amphibians such as cave salamanders, and unique mammals like macaques. Marine biodiversity includes endemic freshwater fish and Mediterranean Sea species. Fig: Map showing Biodiversity Hotspots Option 3 is incorrect: Northwestern Australia, encompassing the Kimberley and Pilbara regions, is known for its rugged landscapes, pristine coastlines, and rich Aboriginal heritage. This remote area features dramatic gorges, waterfalls, and unique wildlife. It also hosts significant mining and resource projects. South-Western Australia is a biodiversity hotspot whereas North-Western Australia is not.

Explanation

Sambhar Lake, situated in Rajasthan, India, holds the distinction of being the nation’s largest inland saline wetland. This expansive lake, located southwest of Jaipur, plays a crucial role in the region’s ecology. Historically renowned for salt production, Sambhar Lake provides a vital habitat for a diverse array of flora and fauna, particularly migratory birds such as flamingos and pelicans. However, the lake faces environmental challenges including pollution, water scarcity, and human encroachment. Despite these challenges, Sambhar Lake remains an ecologically significant and culturally important landmark in Rajasthan.

Explanation

India’s port system comprises two distinct categories: major ports and non-major (minor) ports. As of 2024, the nation has 13 major ports and 217 non-major ports, forming a crucial network for maritime trade. Major ports, strategically administered by the Ministry of Ports, Shipping and Waterways under the Government of India, play a pivotal role in the coun-try’s maritime trade. In contrast, non-major ports come under the jurisdiction of the respective State Maritime Boards, with some also operating under the public-private partnership (PPP) model. Among the given options, Dahej is classified as a non-major port in India. In contrast, Kochi (Cochin), Paradip, and New Mangalore are all designated as major ports.

Explanation

The Shompen tribe is an indigenous and particularly vulnerable tribal group (PVTG) found in the Nicobar Islands, specifically in the Great Nicobar Island. They are semi-no-madic hunter-gatherers who live in the dense forests of Great Nicobar. Their population is very small, and they have minimal contact with outsiders. The Government of India recognizes them as a PVTG under the Andaman and Nicobar (Protection of Aboriginal Tribes) Regulation, 1956.

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

Nilgiri Hills (Tamil Nadu, Kerala, Karnataka): Home to Toda, Kota, Irula, and Kurumba tribes, but not the Shompen Spiti Valley (Himachal Pradesh): Inhabited by Bhotia and Spitians (Tibetan origin people), not the Shompen Lakshadweep Islands: No indigenous tribal communities; the majority population follows Islam.

Explanation

Located in the Kishtwar district of Jammu and Kashmir, India, the Dul Hasti Hydroelectric Power Plant, a 390 MW project, was constructed by the National Hydroelectric Power Corporation (NHPC). This power plant utilizes the run-of-the-river principle, harnessing the flow of the Chenab River to generate electricity.

Explanation

Statement 1 is correct: Tropical deserts indeed form along the western margins of continents within the trade wind belt due to several factors. Trade winds, blowing from east to west, lose moisture on eastern coasts and arrive dry on the western side. These regions lie under subtropical high-pressure belts (15°-30° latitude), where descending air suppresses cloud formation and rainfall. Additionally, cold ocean currents, such as the Humboldt Current, cool the air, reducing its moisture-holding capacity and creating stable, dry conditions. In some cases, mountains block moist winds, causing a rain shadow effect. Together, these factors create arid environments like the Sahara, Atacama, and Namib deserts.

Statement 2 is incorrect: In India, the Eastern Himalayas experience significantly higher rainfall compared to the Western Himalayas. This precipitation is primarily attributed to the South-west monsoon, rather than the Northeast monsoon. The Bay of Bengal branch of the monsoon carries moisture-laden winds that are funneled toward the Eastern Himalayas. When these winds encounter the steep terrain, they rise, cool, and condense, resulting in heavy orographic rainfall. This effect is particularly pronounced in regions like Meghalaya, which receive some of the highest rainfall globally.