Geo-spatial technique-based approach on drainage morphometric analysis at Kalrayan Hills, Tamil Nadu, India

Drainages are pulses which in turn help us to understand the ongoing process in the hill ecosystem. The Kalrayan hill is known for its dissected terrain condition, rich biological diversity and depletion of natural resources. Therefore, a study on quantitative geomorphometry was carried out in the Kalrayan Hills, Eastern Ghats, Tamil Nadu, using Indian remote sensing 1D LISSIII satellite data. The study area was divided into 36 watersheds and total area is 1158.4 km2. It covers the upper part of Vellar basin. The linear, aerial and relief aspects and different morphometric parameters such as stream length, bifurcation ratio, drainage density, stream frequency, drainage texture, relief ratio, basin shape, form factor, circularity ratio, elongation ratio and length of overland flow were computed using standard methods, formulae and geo-spatial technologies. Based on the present drainage morphometric study, it is inferred that the watersheds 3, 4, 6, 9, 11, 12, 15, 17, 18, 19, 20, 22, 24, 27, 32, 33, 34 and 36 are active with reference to geological processes, mean denudational rate, peak discharge, mean annual run off, dominant watershed process and sediment yield per unit area. Multi-criteria analysis is performed to determine the drainage architecture and hydrogeological processes occurring in the present hill area.