Shoreline Change Study in Northwest of Indus Delta using the Temporal Landsat Satellite Data

Mahar, G.-A. and Zaigham N.-A., 2024. Shoreline change study in then northwest of Indus Delta using the landsat satellite data. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 294-299. Charlotte (North Carolina), ISSN 0749-0208. Indus deltaic coast located on the southeastern boundary of Pakistan is rich in biodiversity with prominent features found along the coast. Till early 20th century, delta used to grow seaward naturally, with the support of continuous flow of Indus River carrying sediment towards delta. After the development of irrigation system, natural flow towards delta started to decrease and by the end of 20th century, negligible level of water flow was recorded from Kotri barrage (last barrage of river Indus). This phenomenon distorted many geomorphic features of delta, particularly the shoreline. A temporal study was conducted based on the oldest bathymetry map of the off shore Indus Delta and land sat satellite imageries for the years 1978, 2000, 2007 and 2013. Average retreat rate from 1895 to 2013 is calculated to about 25.35 m/year while within the available data of satellite from 1978 to 2013, the calculated retreat rate is 22.92 m/year. It shows that at the end of the last century the retreat rate was accelerated. Similarly, total submergence area measured for the period 1895 to 2013 was about 331.30 km2 at the rate of 2.80 km2/year but submergence area measured from 1978 to 2013 was 125.24 km2 that was submerged at the rate of 3.47 km2/year, reflecting same scenario of higher submergence in the period of satellite data.