Long term coastal erosion and shoreline positions of Sri Lanka

Abstract

Coastal zone of Sri Lanka is key to the sustainable development of the country. However, the erosion of this coastal zone has been identified as a long term problem. Therefore, coastal sediment dynamics around the country has to be identified to develop an appropriate coastal zone management plan. Remote sensing and GIS techniques can be used for quantitative and qualitative analyses of coastal monitoring activities including understanding the coastal erosion and accretion trends. In this study, past and recent Google Earth satellite images have been used to analyze erosional and accretional trends in the coastal zone, all around Sri Lanka. Using these results, near shore sediment transportation directions along the coastline around the country were also predicted. Most of the south-western coastline of Sri Lanka shows considerable erosion during stormy conditions under south-western monsoon period, but mostly recovered during fair weather northeastern monsoon conditions. Therefore, no any severe long term erosion conditions prevail in the western, south-western and north-western coasts. However, isolated locations in the north-eastern and eastern coastline shows considerable erosion. Predicted nearshore sediment transportation directions proved that it is mainly governed by wind and waves of southwest and northeast monsoons.