Why in News:

• Landslides and flash floods from torrential rains in eastern Indonesia killed at least 41 people and displaced thousands

What is a flash flood

• Flash floods are defined as floods that occur within six hours of heavy rainfall or another cause. 
• These are highly localised events of short duration. However, flash floods can sometimes happen within minutes or just a few hours of a heavy rain. 
• Heavy rainfall isn’t the only potential cause of a flash flood. Melting snow and ice jams in mountain streams can send torrents of water unexpectedly into low-lying areas. Likewise, dam failures can send walls of water downstream without warning.

Issues Associated

• Forecasting of flash floods is tough
• Frequency of events have increased due to climate change
• Himalayas are a volatile mountain system
• Overlooking environmental norms may cause flash floods  and this is primarily seen after dams are constructed without adequate risk analysis.

India’s role

• India is leading a delegation of countries, including Bhutan, Sri Lanka, Bangladesh, and Nepal, in the exchange of hydrological and meteorological data in order to prepare flash flood forecasts.
• The system was developed in collaboration with India’s National Disaster Management Authority (NDMA) and the Central Water Commission (CWC).
• The India Meteorological Department (IMD) has launched the South Asian Flash Flood Guidance System (FFGS), which is designed to assist disaster management teams and governments in developing timely evacuation plans ahead of a flooding event.

Reference:

1. https://www.thehindu.com/news/international/over-41-dead-in-indonesia-flash-floods/article34238844.ece