Landform and Shoreline Changes Inferred from Satellite Images along the Central Kerala Coast

Abstract

The coastal landforms and land use/Land cover changes of central Kerala have been studied with the aid of topographic maps, satellite images and extensive field checks. The landforms identified are barrier islands, beach ridges and swales, strandlines, flood plains and marshy swamps. Several parallely positioned barrier islands and paleo-Beach ridges reveal that the central Kerala coast has been prograding. It is observed that the evolution of coastal landforms is influenced by the fall in sea level and/or uplift of the coast. Extensive occurrence of strandline/Chenier deposits supports the view that the rivers of central Kerala once have supplied enormous amount of sediments.

Land use/Land cover changes, which have occurred during 1966-1995 are quite alarming. The reduction of about 50% in both flood plain and river channel area is due to changes in the land use pattern. Significant changes in the shoreline and morphology of river mouths are recorded. Area of accretional shoreline is more than that of erosion-Prone shoreline. Major morphological changes are observed near the Cochin inlet. The factors affecting the shoreline and landform changes are natural as well as anthropogenic. The natural processes affecting the shoreline changes are sediment supply, coastal processes, and anthropogenic activities such as dredging. Important factors affecting the land use/Land cover changes are reclamation of land for agricultural and industrial purposes, and sand mining in riverbeds and paleostrandline areas.