IWMI provides rapid emergency response maps for Bihar, Assam floods

IWMI provides rapid emergency response maps for Bihar, Assam floods

SHARE
Around 13 of the 38 districts in Bihar has been affected by floods. The crisis has forced thousands of people to evacuate from their homes.

India: With heavy rainfall in the catchment areas in Nepal, the water level of rivers has been rising for several days. Around 13 of the 38 districts of Indian state Bihar has been affected by floods. These include West and East Champaran, Sitamarhi, Madhubani, Darbhanga, Saharsa, Supaul, Araria, Kishanganj, Purnia, Katihar, Khagaria and Muzaffarpur.

Road communication in many districts was snapped as floodwater overtopped national highways. Mahananda, Kosi, Gandak, Bagmati, Burhi Gandak and Kankai were amongst the rivers in spate due to heavy rains in Nepal and its catchment areas. As per government sources, nearly two million people have been affected by the floods in Bihar, including thousands who have been forced to evacuate from their homes. In the last two days, over one million people were affected in the worst-hit districts of Kishanganj, Araria, Purnea and Katihar.

International Water Management Institute (IWMI) under the research program on Water Risks and Disasters (WRD) has utilized European Space Agency’s Sentinel-1 images which can penetrate cloud and provide clear overview of flood affected regions with a spatial resolution less than 10 m, which is very valuable for state and district officials to support in relief operations and post-flood impact assessment. IWMI promotes use of satellite technology in rapid emergency response maps for immediate relief and impact assessment to quantify crop damages and exposed population.

Summary of flood inundation extent using Sentinel-1 taken on August 15, 2017 for the severely flood affected districts in Bihar is given below. Note, the estimates might have some error using sensor calibration, geometric correction and omission of flooded areas due to noise in classification algorithm.

Districts 15th August 2017 Flooded Area (sq.km)
Kishanganj 304.73
Araria 816.31
Bhagalpur 443.47
Katihar 1118.19
Purnia 881.86
Supaul 358.1
Madhepura 362.94

Following are the rapid emergency response maps based on satellite imagery from Sentinel-1:

Mapping crop damages in Araria district of Bihar, India

Mapping inundation extent in the Gandak river and its surroundings (Bihar)

Mapping inundation extent for Nepal and Indian state Uttar Pradesh

Mapping inundation extent for Indian state Uttar Pradesh and Nepal’s Bardiya

Mapping inundation extent for Lakhimpur, Jorhat, Golaghat, Sonitpur in Assam

Mapping inundation extent for Lakhimpur, Jorhat, Golaghat, Sonitpur in Assam

Mapping inundation extent for Madhepura and Bhagalpur districts of Bihar

Mapping inundation extent for Bihar

Mapping inundation extent for Bihar’s western Champaran

Mapping inundation extent for Bihar

Mapping inundation extent for Lakhimpur, Jorhat, Golaghat, Sonitpur in Assam

IWMI would like to acknowledge the support CGIAR Research Program on Water, Land and Ecosystems (WLE), Climate Change, Agriculture and Food Security (CCAFS), Indian Council of Agricultural Research (ICAR) Japan’s Ministry of Agriculture, Forestry and Fisheries (MAFF) and UNOOSA/UNSPIDER Regional Support Office.