Description

Copyright infringement not intended

Source: Science

Context

Flash floods kill around 5,000 individuals in India each year. With rising global temperatures, they are likely to grow more frequent and intense.

Flash floods are fast and rapid floods that occur quickly, usually within hours following severe rainfall or other intense water buildup occurrences.
The National Weather Service, the US meteorological organization, defines flash floods as flooding induced by rainfall in less than six hours.
They are distinguished by a rapid rise in water levels in rivers, streams, or urban areas, which occurs with little to no warning.

Aside from heavy rain, flash floods can be triggered by dam or levee collapses, ice or debris jams, or the unexpected release of water from natural reservoirs such as glacial lakes.
In India, flash floods are frequently related with cloudbursts, which are abrupt, strong rains that occur in a short period of time.
Flash floods can also be caused by factors such as rainfall intensity and duration, topography steepness, soil type, and the existence of man-made structures that obstruct water movement.

Flash floods are notorious for their high force and rapidity, transporting massive amounts of water, debris, and silt.
They can overrun drainage systems, cause rivers to overflow, and flood low-lying communities.
Flash flooding is more likely in areas where rivers are small and steep, allowing them to flow faster.
They can arise in urban areas near minor rivers because hard surfaces like highways and concrete prevent water from absorbing into the ground.

The Central Water Commission (CWC), established in 1945, works on flood control, water resource conservation, irrigation, hydropower generation, flood management, and river conservation in the country.
The National Disaster Management Authority (NDMA) has created Guidelines for Flood Management to help ministries, departments, state governments, and other entities develop Flood Management Plans (FMPs).
National Water Policy (2012):It focuses flood management through structural measures, integrated reservoir operation, natural drainage system restoration, farming systems, and non-agricultural development, with the goal of providing long-term solutions to severe floods.
Flood Forecasting Network: The CWC has established a flood forecasting system with 175 stations across important interstate rivers, enabling real-time data collecting, automatic transmission, flood forecast formulation, and efficient information distribution.
The Flood Management and Border Areas Programme (FMBAP) is being implemented across the country to improve flood management, erosion control, and anti-sea erosion, while also promoting peace along borders.

Pratice Questions:

Q. Which of the following statements regarding flash floods is/are correct?

Select the correct answer using the code given below:

A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2 and 3

A) 1 and 2 only

Statement 1: Correct. According to the US National Weather Service, flash floods occur when flooding happens within six hours of rainfall.
Statement 2: Correct. In India, cloudbursts are a major contributor to flash floods, especially in Himalayan regions.
Statement 3: Incorrect. Flash floods can also occur in urban areas, particularly due to impermeable surfaces like roads and buildings that prevent water absorption