Mapping and assessment of flood risk in Prayagraj district, India: a GIS and remote sensing study

Abstract

Flood is a catastrophic natural disaster event that is immensely threatening and affecting ecosystems as well as human lives all over the world. Flood frequently occurs in Indian districts during the monsoon season. Districts situated near the rivers are more prone to the flood risk. It is not possible to completely eliminate the flood risk, but its impact can be significantly reduced by geographic information system (GIS) and remote sensing-based solutions. This study is an attempt to calculate the extent of past floods and land use/land cover (LULC) classes affected by flooding using the GIS and remote sensing technique in the Prayagraj district of India. The flood risk mapping is performed by integrating the GIS with multi-criteria decision-making method called analytical hierarchy process (AHP). Flood affecting parameters are identified, which are drainage density, elevation, flow accumulation, LULC, roughness, slope and topographic wetness index. A flood risk map is generated through AHP and validated by the ROC curve method. Flood risk map has revealed that in the study area 701.71 km2 (12.80%) region comes under the high risk, while 1273.0 km2 (23.22.8%) region comes under the moderate risk.