Geomorphology of the Goa Coast

Abstract

This paper is based on the observations and interpretations of aerial photographs (1;25, 000 and 1:15, 000) of the Goa Coast. Aerial photocharacters like zonal differences, texture, shape, size, form, pattern, vegetation, soil characteristics and associated features were useful in identifying fluvial, marine and aeolian features such as tidal flats, river terraces, mesas, wave-cut platforms, old beach ridges, dunes, etc. The drainage network is predominantly in two directions coinciding with the regional trend, major faults and fractures and represents a fine example of a structurally controlled drainage pattern. The islands near the coast are parts of coastal headlands now isolated from the retrograding coast. Some of laterite beds at a depth of 27 to 35 m below the present sea level along the estuaries indicates the drowned valleys. Geomorphological evidences show that the coastal tract of Goa has undergone the following stages after the outpouring of Deccan Traps: epirogenic movement; headward erosion; recession of scarps; superposition of the streams; lateritization; submergence; emergence; progradation and retrogression. Based on the disposition of the landforms it is surmised that the coast is prograding along the sandy stretches and retrograding along the hilly portions