Cyclone & Flood Management — Set 3

Correct Answer: B. Jakhau Port, Gujarat

Cyclone Biparjoy made landfall near Jakhau port in the Kutch district of Gujarat on June 15, 2023. The cyclone had an unusually long lifespan of about 13 days in the Arabian Sea before making landfall. Timely evacuation of over 100,000 people helped minimize casualties despite the cyclone's severity.

Correct Answer: C. Depression

Depression is the first formal classification in IMD's tropical cyclone intensity scale, with sustained wind speeds of 31–49 km/h. Below Depression, a weather system is classified only as a Low Pressure Area. The full IMD scale progresses from Depression to Deep Depression, Cyclonic Storm, Severe, Very Severe, Extremely Severe, and Super Cyclonic Storm.

Correct Answer: B. Cyclonic Storm

In the IMD cyclone intensity scale, 'Cyclonic Storm' comes after 'Deep Depression.' A Cyclonic Storm has sustained wind speeds of 63–88 km/h. The progression is: Depression, Deep Depression, Cyclonic Storm, Severe Cyclonic Storm, Very Severe Cyclonic Storm, Extremely Severe Cyclonic Storm, and Super Cyclonic Storm.

Correct Answer: C. Super Cyclonic Storm

Super Cyclonic Storm is the highest category in the IMD cyclone classification scale, with sustained wind speeds exceeding 220 km/h. The 1999 Odisha cyclone and Cyclone Amphan at peak intensity reached this classification. IMD does not use the 1–5 Saffir-Simpson scale; it has its own seven-tier classification system.

Correct Answer: C. 48–72 hours

IMD issues cyclone warnings 48–72 hours before expected landfall, allowing time for evacuation and preparedness measures. This early warning capability has been significantly improved over the years through use of satellites, buoys, and advanced modelling. Timely warnings have been credited with saving thousands of lives in recent cyclone events.

Correct Answer: C. Mangrove forests

Mangrove forests act as a natural protective barrier against cyclones and storm surges by absorbing wave energy and reducing wind force. They are often called the 'green wall' against cyclones. The Sundarbans mangroves in West Bengal have provided significant protection during several major cyclones including Aila and Amphan.

Correct Answer: B. Row of trees planted as windbreaker

A shelter belt is a row of trees planted along coastal areas to act as a windbreaker and reduce the impact of cyclonic winds on settlements and farmland. Shelter belts, along with mangrove restoration, are key components of cyclone preparedness in coastal India. They also help reduce soil erosion and salt spray intrusion during storm surges.

Correct Answer: C. Flash flood

Flash floods are caused by heavy or excessive rainfall on steep slopes or in narrow valleys and occur very rapidly, often with little warning. They are particularly dangerous in hilly and mountainous terrain. The 2013 Uttarakhand disaster was a catastrophic flash flood event that killed thousands of people in the Himalayan region.

Correct Answer: B. Riverine flood

Riverine floods occur when rivers overflow their banks due to prolonged or heavy rainfall, snowmelt, or dam releases upstream. They are the most common type of flooding in India and affect large areas along major river systems. Rivers like the Brahmaputra, Ganga, and Kosi are notorious for causing severe riverine floods annually.

Correct Answer: B. Poor drainage and impervious surfaces in cities

Urban flooding is primarily caused by the combination of poor drainage infrastructure, impervious surfaces like roads and buildings that prevent water absorption, and rapid runoff in cities. As cities expand, the natural drainage capacity of land is reduced significantly. Mumbai in 2005 and Chennai in 2015 experienced devastating urban floods due to these factors.