Drainage Characteristics of Achankovil River Basin, Kerala

Achankovil River sets in one of the major shear zones of Southern India which separates the Kerala Khondahte Belt (KKB) and Charnockite terrain. In this paper morphometnc characteristics of the river basin developed in a shear zone is reported. Major basin parameters like linear, aerial and relief parameters of the basin indicate that the basin architecture is much influenced by this prominent shear zone. Development of rectangular, parallel and trellis drainage patterns and parameters like bifurcation ratio, elongation ratio, are clear evidences for the structural control. Further, main river course is oriented m WNW-ESE direction, which follow the trend of the Achankovil shear zone and most of the lower order streams are developed roughly at right angles to the main river course.