Morphometric analysis and tectonic implications of the Chinnar river basin using remote sensing and GIS, Southern India

This study presents a morphometric evaluation of the Chinnar River basin in the hard rock terrain of Perambalur District, Tamil Nadu, India, to determine its geomorphic maturity and ongoing tectonic influence. Shuttle Radar Topography Mission (SRTM) data were used to prepare digital elevation model (DEM), slope maps, and aspect grids, while morphometric parameters related to areal, linear, and relief aspects were analyzed using the ArcGIS platform. Quantitative analysis shows that the basin is elongated (elongation ratio = 0.58) with a coarse drainage network, low drainage density, and limited structural control (Bifurcation ratio = 2.17). More than 70% of the basin exhibits a low slope, indicating strong potential for groundwater recharge and future water development. Hypsometric and channel form analyses confirm that the basin is in an advanced/older stage of fluvial evolution, characterized by a sinuous channel, marked basin asymmetry, vertical deformation, and persistent neotectonic activity. The stream order ranges from first to fifth, with drainage patterns predominantly dendritic to sub-trellis. The basin flow direction is primarily from southwest to northeast. Relief analysis shows varied topography from highlands to plains, reflecting the influence of lithology, slope, and hydrological processes on channel morphology and sediment transport. These morphometric signatures demonstrate that tectonic activity continues to shape the drainage architecture and landscape development in the region. The findings provide critical constraints for groundwater planning, watershed prioritization, and sustainable water resource strategies in crystalline basins, supporting long-term management in water-stressed hard rock districts.