UPSC 2011 Geography Questions with Answers

Explanation

Statement 1 is correct: The primary reason the westerlies in the Southern Hemisphere are stronger and more persistent than in the Northern Hemisphere is because the Southern Hemisphere has significantly less landmass (about 20% land and 80% water), whereas the Northern Hemisphere has 40% land and 60% water. The vast oceans in the Southern Hemisphere allow westerly winds to move with minimal obstruction, making them stronger and more persistent. In contrast, larger landmasses in the Northern Hemisphere create friction and disrupt wind flow.

Statement 2 is incorrect: The Coriolis force acts equally in both hemispheres at the same latitude as it depends on the Earth’s rotation and the latitude. It does not make the westerlies stronger in one hemisphere over the other. The main reason for the difference is the land-sea distribution. The Coriolis force is stronger near the poles and weaker at the equator, but it does not explain the difference in strength of the westerlies between the two hemispheres.

Explanation

Statement 1 is correct: The African and Eurasian desert belt (Sahara, Arabian, Thar, Gobi) lies in the sub-tropical high-pres-sure zone (20°-30° latitudes). In this region, descending dry air from the Hadley Cell suppresses cloud formation and rainfall, creating arid conditions. This becomes the main reason for the formation of these deserts.

Statement 2 is incorrect: Warm ocean currents increase evaporation followed by humidity, leading to higher rainfall in coastal areas rather than desert formation. Deserts are mainly found near cold ocean currents (e.g., the Atacama Desert near the Peru Current, the Namib Desert near the Benguela Current), which cool the air and reduce its moisture-holding capacity, causing dry conditions. Moreover, many deserts in this belt are landlocked, far from direct oceanic influence.

Explanation

Statement 1 is correct: The lower stratosphere is mostly free from clouds and water vapor, as most weather phenomena occur in the troposphere below. This impacts the clear air conditions, making it ideal for jet aircraft to fly smoothly.

Statement 2 is correct: The stratosphere is a stable layer with no vertical air movements like convection currents. In contrast, the troposphere experiences turbulence due to rising and falling air masses. The absence of vertical winds in the lower stratosphere ensures a steady flight for jet aircraft.

Explanation

Mangroves function as a safety hedge due to their extensive root systems. These roots act as a natural barrier, protecting coastlines from erosion and the impact of strong waves during storms, cyclones, and tsunamis. The dense network of roots helps to dissipate the energy of waves, reducing their im-pact on the shoreline.

Explanation

Statement 1 is incorrect: La Niña is characterized by unusually cold ocean temperatures in the Equatorial Pacific (not the Indian Ocean). In contrast, El Niño is associated with unusually warm ocean temperatures in the Equatorial Pacific Ocean.

Statement 2 is incorrect: El Niño events are associated with a weakening of the Indian monsoon leading to reduced rainfall and drought conditions in India. This occurs because the warming of the central and eastern Pacific Ocean alters atmospheric circulation patterns, which can suppress the monsoon rains over the Indian subcontinent. La Niña events typically have the opposite effect, strengthening the Indian monsoon and often resulting in above-average rainfall. The cooling of the central and eastern Pacific Ocean during La Niña enhances the monsoon circulation, leading to increased precipitation over India.

Explanation

The crop suitable to be grown in the lower Gangetic plain, which is characterized by a humid climate with high temperature throughout the year, is Paddy and Jute. Paddy: It grows well in the plains of north and north-eastern India, coastal areas and the deltaic regions, where there is an abundance of alluvial clayey soil. A high temperature (above 25°C) and significant humidity are necessary for this kharif crop. Jute: Its cultivation is mainly concentrated in eastern India because of the rich alluvial soil of Ganga-Brahmaputra delta. Jute crops need humid conditions with temperature swings between 24 and 38 degrees Celsius.

Explanation

Salinization refers to the accumulation of soluble salts in the soil resulting from irrigation practices where water evaporates, leaving salts behind. This process adversely affects soil structure and fertility.

Option (a) is incorrect: Salinization reduces crop yields as excess salts in the soil create osmotic stress on plants which hin-ders their ability to absorb water and nutrients. This leads to stunted growth and lower productivity.

Option (b) is correct: Salinization causes soil particles to disperse and clog pores which makes the soil impermeable. This is known as sodic soil degradation. This dispersion leads to the clogging of soil pores, reducing permeability and making the soil less capable of absorbing water. Thus water infiltration decreases and the soil becomes impermeable.

Option (c) is incorrect: Salinization generally occurs due to poor drainage but it does not necessarily raise the water table. On the contrary, a high water table can exacerbate salinization by bringing saline groundwater closer to the root zone through capillary action.

Option (d) is incorrect: Salinization does not directly fill air spaces in the soil with water. It can lead to waterlogging due to reduced soil permeability which indirectly affects soil aeration. Waterlogging displaces air from soil pores which deprives plant roots of oxygen.

Explanation

Arunachal Pradesh, often referred to as the "Orchid Paradise of India,". It boasts over 600 orchid species, accounting for approximately 40% of the country’s orchid diversity. The state’s sub-alpine and sub-tropical climates provide ideal conditions for orchid cultivation which makes it highly suitable for developing an export-oriented industry with minimal production costs.

Explanation

The above characteristics clearly define Gujarat.

The northern region of Gujarat comprises the Kutch and Banaskantha districts, which are characterized by arid and semi-arid conditions due to low annual rainfall (less than 500 mm). The Thar Desert extends into parts of Gujarat, contributing to the dry climate. Gujarat is the largest producer of cotton in India (~30% of national production). The central districts, such as Ahmedabad, Surendranagar, Rajkot, and Bhavnagar, have ideal black soil (Regur soil) that supports cotton cultivation. Gujarat is highly commercialized in agriculture, focusing on cotton, groundnut, tobacco, and castor rather than food crops. The Saurashtra and Kutch regions specialize in cash crops due to their soil type and climatic conditions.

Explanation

The river originating in Jharkhand referred to here is the Brahmani River. It originates as the Koel River in Jharkhand and is later called the Brahmani in Odisha. River originating in Odishas is the Baitarani River which originates in the Ke-onjhar district of Odisha. The Brahmani and Baitarani rivers merge at a place called Dhamra, near the Bay of Bengal forming a large delta before flowing into the sea. Bhitarkanika National Park is located in the estuarine region formed by the merging of the Brahmani and Baitarani rivers. It is located in the Kendrapara district of Odisha. It is a unique ecosystem of mangroves, wetlands, and tidal rivers. It is one of India’s most important wildlife sanctuaries and a Ramsar site (a wetland of international importance). It is home to saltwater crocodiles, Olive Ridley sea turtles, and a variety of bird species.