Spatial dynamics of inheritance to transience in the landscape and the evolutionary history, the Vaigai River Basin, Southern India

Quantitative morphometric parameters help assess the landscape evolutionary history at the basin scale and recognise and link prevalent field- regional-scale tectono-climatic processes. In this paper, the spatial distributions of morphometric parameters are assessed on a second-order watershed scale to evaluate relative influences of tectonic, climatic, and lithological controls within the Vaigai River Basin, Southern India. The results show that the elongated eighth-order Vaigai River Basin is prone to high surface run-off, low infiltration rates and headward erosion. Prevalent and ongoing tectonic activities in the upstream regions are recognised by the index of relative active tectonics and evidenced by the frequent occurrences of knickpoints. The geomorphic indices, namely, sinuosity, transverse symmetry, basin shape index, and asymmetry factor, indicated the dominance of structural controls, and are also evidenced by the occurrences of only small meanders, and migration of river channels away from the midline of the watersheds. Compilation of these results and interpretations characterises the Vaigai River Basin as an antecedent basin that is in transience, though restricted/delimited by inherited structural-geomorphic features. Resurgence of tectonic activism, relicts of paleoclimatic signatures and localised lithological controls are all documented by the present study.