Geospatial Analysis Of Flood Susceptibility In Dera Ghazi Khan, Along River Indus

Abstract

Pakistan faced one of the most devastating floods in 2010 and the severity of the floods have risen since then, hitting Pakistan with distressing floods in 2022. This study focuses on developing flood hazard maps using GIS centered Flood Hazard index (FHI), for Areas under DG Khan division including DG Khan, Taunsa, Layyah, Kot Addu, Kott Chutta, and DG Khan Tribal areas. Seven flood parameters were contemplated including Rainfall, Land use/Land cover (LULC), Flow accumulation, Distance from the river, elevation, and slope. These parameters are obtained from USGS Earth Explorer and CHRIPS. The analysis was conducted by using three steps: Map Reclassifications of each parameter, Weighting, Weighted Overlay Analysis. Each parameter is reclassified and given appropriate weightage. Assigned percentage weight for each parameter indicates relevant importance to the severity and occurrence of flood. Using ArcGIS 10.4.1 all the parameters are unified to create Flood hazard index (FHI) map which indicated that 20.70% of the study area from 2010 and 41.80% from 2022 came under Very High-Risk zones. High risk zones spanned 65.93% of AOI in 2010 and 58.27% in 2022 and the remaining area was coming under low-risk zone. High susceptibility to floods was shown by the areas within the vicinity of river Indus i.e Taunsa, Layyah, Northern areas of DG Khan, western regions of Kot Addu. High risk areas increased from the year 2010 to 2022 as indicated by FHI. The proposed methodology would be helpful in early preparedness and tackling with floods in an effective manner.