Natural and Man Made Disasters

60,000 km²

Step 1: The Kosi river is a major tributary of the Ganga and is responsible for much of Bihar's flood misery. Step 2: According to the textbook, the Kosi river system drains about 60,000 km² of eastern Nepal and southern Tibet before entering Bihar. Step 3: The basin includes almost half of the world's 8,000 m plus peaks, making it a massive catchment area. Step 4: The other options — 30,000, 45,000, and 80,000 km² — are incorrect figures. Step 5: Understanding the large drainage area helps explain why even heavy rainfall in Nepal can cause devastating floods downstream in Bihar.

80 per cent

Step 1: During the 2016 Assam floods, the Kaziranga National Park — a UNESCO World Heritage Site — was severely affected. Step 2: As of 2 August 2016, around 80 per cent of the Kaziranga National Park was reported to be under water. Step 3: As a result, around 300 wild animals were reported to have drowned, including 21 great one-horned rhinoceroses. Step 4: The other options (50%, 65%, 95%) are incorrect figures. Step 5: This highlights the severe impact of floods not just on human life but also on wildlife and ecosystems.

Prince William Sound, Alaska

Step 1: The Exxon Valdez oil spill is considered one of the most devastating human-caused environmental disasters. Step 2: It occurred on March 24, 1989, in Prince William Sound, Alaska, when the oil tanker struck Bligh Reef. Step 3: The oil eventually covered 1,300 miles (2,100 km) of coastline and 11,000 square miles of ocean. Step 4: Cook Inlet, Gulf of Alaska, and Norton Sound are all Alaskan water bodies but are not the location of this specific spill. Step 5: The remote location of Prince William Sound made rescue and cleanup efforts extremely difficult.

Chorabari glacier

Step 1: In June 2013, Uttarakhand and adjoining areas experienced heavy rainfall about 375% more than normal benchmark rainfall. Step 2: This extreme rainfall caused the melting of the Chorabari glacier at the height of 3800 metres. Step 3: This led to the eruption of the Mandakini river, causing heavy floods near Gobind Ghat, Kedar Dham, Rudraprayag, and Uttarakhand. Step 4: The Gangotri, Siachen, and Milam glaciers are all Himalayan glaciers but were not specifically named as the cause of the 2013 Uttarakhand disaster. Step 5: About 5,748 people went missing and approximately 1,000 people we