Shoreline change assessment of Indus delta using GIS-DSAS and satellite data

Abstract

Indus River Delta, Pakistan, is under continual threat of coastal erosion due to natural and anthropogenic activities. The variations in the shoreline position have significantly degraded agricultural lands, increased tidal floodplain areas, and subsequently affected the livelihood of the coastal communities under changing climatic scenarios. The present study was conducted to quantify the Indus delta shoreline variations using satellite data and the Digital Shoreline Analysis System (DSAS 4.3) integrated with ArcGIS software. The statistical parameters End Point Rate (EPR) and Linear regression rate (LRR) were used for estimation of the shoreline change rate, while Net Shoreline Movement (NSM) was used to estimate the net change in the shoreline from 1972 to 2017. The analysis of results revealed that the erosion of the shoreline was dominant over the accretion, which ranged between 1 to 160 m/year with a net erosion rate of 18.87 ± 2.22 m/year. The net shoreline erosion rate was higher, i.e., 30.12 ± 3.13 m/year on the left bank side of the river Indus, compared to that of on the right bank side, i.e., 6.34 ± 2.85 m/year. The net landward shift in the shoreline of the delta from 1972 to 2017 was 860 ± 92 m. The DSAS software integrated with ArcGIS could successfully be used for shoreline change analysis for similar river deltaic areas of the World. The study recommends the employment of mitigation measures for the protection of the shoreline of the Indus delta.