UPSC Essentials | Daily subject-wise quiz : Environment and Geography MCQs on rainfall in winters, ecological degradation of forests and more (Week 146)

Which one of the following is correct in respect of the above statements?

(a) Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1.

(b) Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation for Statement 1.

(c) Statement 1 is correct but Statement 2 is incorrect.

(d) Statement 1 is incorrect but Statement 2 is correct.

Relevance: This question tests understanding of India’s winter rainfall mechanism and role of Western Disturbances, a core concept in Indian climatology. It is frequently asked in concept-based elimination MCQs linking atmospheric circulation with regional weather patterns.

Explanation

— The 2024-25 winter season had seen rainfall deficiency of 96 per cent in the northwestern region. Studies have shown a marginal declining trend in the winter season rainfall over some pockets of north India.

— During winters, the north and northwest India regions normally experience light to moderate intensity rainfall mainly triggered by the passing streams of western disturbances. This precipitation is particularly vital for the rabi crops cultivated along the plains and supported by irrigation. In the higher altitudes, snow or rainfall is key for the recharge of the groundwater aquifers. Hence, statements 1 and 2 are correct.

— In December and January, streams of passing western disturbances normally interact with moisture-laden easterly or westerly winds coming in from either the Bay of Bengal or the Arabian Sea. This creates a wind confluence that happens normally over the Himalayas. It results in precipitation in the form of snow or rainfall.

Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1.

Therefore, option (a) is the correct answer.

QUESTION 2

The Polavaram Irrigation Project was recently in the news. It is constructed across the:

(a) Cauvery River

(b) Krishna River

(c) Godavari River

(d) Mahanadi River

Relevance: This question tests mapping-based knowledge of major river valley projects and their associated rivers, a recurring UPSC theme. It is important due to federal disputes, environmental clearances, and inter-state water-sharing issues, making it a current-affairs-linked static topic.

Explanation

— The Supreme Court disposed of a writ petition filed by the state of Telangana against the Union government and the state of Andhra Pradesh over the proposed expansion of the Polavaram-Banakacherla Link Project.

— The matter pertains to Andhra Pradesh’s Polavaram Irrigation Project on the Godavari River, which originates in the Western Ghats, flows through Maharashtra, and drains into the Bay of Bengal.

— Polavaram was permitted to divert 80 thousand million cubic feet (TMC) of water from the Godavari to the Krishna River through its canal system for use in the Krishna Delta. The project is governed by the Godavari Water Disputes Tribunal (GWDT) Award and technical clearances issued by the Central Water Commission.

Therefore, option (c) is the correct answer.

QUESTION 3

Consider the following statements:

1. Carbon sinks play a crucial role in maintaining the Earth’s carbon cycle.

2. Oceans function as net carbon sources rather than carbon sinks.

3. Forests release more carbon than they absorb over long time scales.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Relevance: This question tests conceptual clarity on carbon cycle, carbon sinks, and climate change mitigation mechanisms, a high-frequency UPSC theme. It is important due to links with India’s climate commitments, net-zero targets, carbon markets, and environmental policies.

Explanation

— The year 2025 was the third-warmest year on record, according to a new analysis by the Copernicus Climate Change Service, the European Union’s Earth observation programme. The global surface air temperature was 1.47 degrees Celsius above the pre-industrial level (1850-1900) in 2025.

— The year was marginally cooler than 2023 — global surface temperature stood at 1.46 degrees Celsius — and 0.13 degrees Celsius cooler than 2024, the hottest year on record (mercury touched 1.60 degrees Celsius). This means that the average temperature in the past three years was 1.51 degrees Celsius, exceeding the 1.5-degree Celsius limit set by the 2015 Paris Agreement.

— Carbon sinks have been critical to preserving the Earth’s carbon cycle. That is because they absorb more CO2 from the atmosphere than they emit. Forests and oceans are among the most major natural carbon sinks. Hence, statement 1 is correct.

— Oceans absorb approximately 25-30% of anthropogenic CO₂ emissions, rather than being net sources. Hence, statement 2 is not correct.

— Forests are often net carbon sinks over long time scales, absorbing more carbon through photosynthesis than they emit unless disturbed (deforestation, fires, degradation). Hence, statement 3 is not correct.

Therefore, option (a) is the correct answer.

QUESTION 4

Which of the following factors can contribute to the ecological degradation of forests?

1. Repeated forest fires

2. Fungal infections

3. Insect infestation

4. Increasing anthropogenic pressures

Select the correct answer using the codes given below:

(a) 1 and 4 only

(b) 1, 2 and 4

(c) 2 and 3 only

(d) 1, 2, 3 and 4

Relevance: This question tests understanding of drivers of forest degradation and ecosystem stress, a core theme in environment & ecology. It is highly relevant due to links with climate change, biodiversity loss, forest conservation policies, and India’s carbon sink targets.

Explanation

— An in-depth study conducted by experts from Dr Y S Parmar University of Horticulture and Forestry, Nauni, has concluded that forest ecosystems across Sirmaur, Shimla, and Solan districts of Himachal Pradesh are in a state of critical ecological decline, primarily due to the long-term impact of repeated forest fires, compounded by insect infestation, fungal infections, and increasing anthropogenic pressures.

— The study found that despite variations in vegetation—from century-old Ban Oak (Quercus leucotrichophora) forests in Sirmaur to Pine-dominated stands in Shimla and Solan—the underlying cause of widespread tree mortality across all three regions was historical and recurring forest fires that have severely weakened the forests’ natural resilience.

Therefore, option (d) is the correct answer.

QUESTION 5

Diego Garcia is located in:

(a) Southern Pacific Ocean

(b) Eastern Atlantic Ocean

(c) Indian Ocean

(d) Arctic Sea

Relevance: This question tests strategic geography and mapping skills, especially of important islands, atolls, and oceanic regions. It is highly relevant due to Indo-Pacific geopolitics, maritime security, and military-strategic significance of island bases.

Explanation

— On a day marking one year since his inauguration as the President of the United States, Donald Trump reiterated his country’s intentions to take control of Greenland. The assertions are in line with the year that has gone by, where, under Trump, the US has attacked countries like Iran and Venezuela, and increasingly projected the Western hemisphere as a zone under American influence. However, Trump cited a new rationale for the Greenland bid: the case of Diego Garcia.

— In October 2024, the UK government announced it would cede sovereignty of the strategically important Chagos Islands to Mauritius, calling it a “historic political agreement”. The UK has long controlled Chagos and the Diego Garcia military base located there, jointly operating it with the United States.

— The Chagos archipelago, comprising 58 islands, lies roughly 500 km to the south of the Maldives archipelago in the Indian Ocean. These islands were uninhabited until the late 18th century, when the French brought in slave labour from Africa and India to work in newly established coconut plantations. In 1814, France ceded the islands to the British.

Therefore, option (c) is the correct answer.

Previous Daily Subject-Wise-Quiz

Daily Subject-wise quiz — History, Culture, and Social Issues (Week 141)

Daily subject-wise quiz — Polity and Governance (Week 146)

Daily subject-wise quiz —  Science and Technology (Week 146)

Daily subject-wise quiz — Economy (Week 146)

Daily subject-wise quiz — Environment and Geography (Week 145)

Daily subject-wise quiz – International Relations (Week 145)

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