Sreeja I.S.¹, Binoj Kumar R.B.¹, Rajesh Reghunath¹, Yogendra Singh², Mohammed Noohu Nazeer^{2, 3,}

Quantitative assessment of drainage basin through morphometric analysis is one of the important methods in hydrological and hydrogeological investigations. In the last couple of decades, Geographical Information System (GIS) techniques are being used in such analysis and has become an important tool, for assessing various terrain and morphometric parameters of the drainage basins, as it provides a comfortable and reliable environment for the analysis and interpretation of spatial information. In the present study, an attempt has been made to evaluate the morphometric characteristics of Pallimon watershed for the assement of hydrogeological conditions. The objective of the present study is to analyse the linear, areal, and relief morphometric attributes of Pallimon watershed and the 13 sub basins, South Kerala, India, and its third-order sub-basins, using Geographical Information System. The basin is characterised by a well-developed dendritic drainage pattern, wherein the sub-basins and falls under the moderate to a well-drained category, representing the influence of geological characteristics on drainage development. It is found that the river basin development is in the mature stage. The structural control over the river basin development is lesser in most parts of the area, which is evident from the lower constant of channel maintenance values. The relief aspect indicates that the basin is characterised by high recharge and is less susceptible to soil erosion. The study also indicates that the Pallimon watershed as a whole and its sub-basins are characterised with complex physiography and structures.

Pallimon watershed, morphometric analysis, hydrological analysis, DEM