Shifting of the gosthani river mouth at Bheemunipatnam, Andhra Pradesh, east coast of India using remote sensing and GIS techniques

River mouths are dynamic especially in tropical coast line. Human activities within and around the river mouths such as navigation, agriculture, fisheries, aquaculture, transportation and communication, recreation etc., promote economic growth of the area, and therefore it is essential to maintain stable condition around the river mouth. There are several problems associated with a river mouths such as, sedimentation and siltation, shifting of the river mouth and erosion of the river bank. The Gosthani river mouth is one such environment. Sand dredging is going on to overcome the problems due to heavy sediment deposition. In order to understand the causes, mechanism and to infer trends of changes Remote sensing and Geographical information system technology has been employed to understand the dynamic environment. Multi-date image analysis for the period from2001 and 2021 has been carried out to understand morphological changes around the estuary. Multi-date image analysis revealed a paired spits -one growing from north to south another growing from south to north, of which northern spit is growing dominantly at the expense of southern spit simultaneously with shifting of the river mouth southward. Number of sand bars and mudflats present in the estuary indicate landward and shoreward movement of sediments in different seasons. Further growth of northern spit in the coming years is also expected and hence the river mouth shifting, which affects the habitat nearby and human activity is to be checked.