Modelling Flash Flood Vulnerability and Sensitivity Dynamics of Jiadhal River Basin of Eastern Himalayan Range Using Space Technology and AHP

Abstract

Flood vulnerability mapping is significant for flood susceptibility analysis. This study aims to identify and assess the dynamics of flood vulnerability zones of Jiadhal River basin where flash flood is a frequent event in Monsoon. Space technologies such as remote sensing and geospatial technology were employed for investigating flood vulnerability. Influential parameters such as distance from river, elevation, surface roughness, drainage density, slope, soil texture and LULC (land use and land cover) were used in this study. Relative importance of these influential parameters, that is, priority weights were computed using analytical hierarchy process (AHP) method. Next, computed priority weights were used to identify and assess the dynamics of flood vulnerability zones. It has been observed that areas which is near to the river and are located at low elevation areas of river bed are in the high and very high vulnerability zones. Consequently, around 406.7 (35%) and 211.4 km2 (18%) of the study area has been severely affected by flash flood.