Abstract
This study employed remote sensing data, geographic information systems, and statistical methods to analyze the morphometric features of the Antsokia watershed and its sub-watersheds. It assessed drainage network, watershed geometry, drainage texture, and relief characteristics. The Antsokia watershed is drained mainly by a sixth-order river with a dendritic pattern. The mean bifurcation ratio (Rb) was 3.9, indicating a typical branching pattern, while sub-watersheds showed higher Rb values (>5), suggesting steep terrain. The longest flow path is 42.5 km, marked by knickpoints due to lithological changes and major faults. The watershed’s elongated shape indicates longer peak flows, aiding flood management. Drainage texture analysis revealed fine drainage, implying soft rock prone to erosion prevails. Most of the watershed comprises high relief and steep slopes (78 %), including hills, breaks, and low mountains. The S-shaped hypsometric curve with a hypsometric integral of 0.4 suggests the watershed is in a mature stage of geomorphic evolution and equilibrium. Sub-watershed morphometric parameters varied spatially, categorized into low, moderate, and high clusters. Overall, this study enhances understanding of Antsokia watershed’s characteristics, aiding in sustainable resource management and decision-making.