Explanation:

Assam is one of the flood prone States in the country. In order to minimise the impact of the floods in the State, Government of Assam approached National Remote Sensing Centre (NRSC),ISRO, Hyderabad for identifying the flood hazard level of various villages in the State.

Satellite images depict the extent of flooding and flood inundated areas can be identified using digital image analysis techniques. Using 215 satellite images acquired during floods of last 18 years (1998-2015), most frequently inundated districts and villages were identified, based on the frequency of inundation. Villages were categorised into five hazard classes as Very High, High, Moderate, Low and Very Low.

An updated ‘Flood Hazard Atlas for Assam State’ was prepared and the maps were validated by the Govt. of Assam through Assam State Disaster Management Authority (ASDMA). The atlas provides information on frequently flooded villages in the State of Assam and also provides the flood hazard severity in different districts based on flood hazard category, flood hazard area and intra-annual flood variations.

About 28.75% (22.54 lakh hectares) of land in Assam State is affected by flood during 1998-2015. It is also observed that 17 out of 34 districts in Assam are severely flood affected.