Morphometric Analysis of Olanthichira Watershed using Geographic Information System in Malappuram District, Kerala, India

Morphometric analysis of watershed is important for understanding its geo-hydrological behaviour. The objective of this study is to determine morphometric parameters of Olanthichira watershed, Kuttipuram block, Malappuram district of state Kerala, India. The stream channels of the watershed were extracted from SRTM DEM and SOI topographical maps on 1:50,000 scale using Hydrology tools in Arc GIS software showing dendritic drainage pattern. Then morphometric analysis is carried out by determining parameters of linear, areal and relief aspects. Drainage density of 1.836 km/km2 is moderate suggests semi-permeable rocks, moderate relief, and a balanced hydrological response. The drainage texture of watershed is 4.359/km indicates a moderate to fine drainage texture means the watershed has a fairly advanced drainage system, with a moderate number of stream channels with highest channel maintenance constant of 0.544 experiencing low runoff and fewer structural disruptions. The moderate bifurcation ratio of 3.68 in a drainage network suggests that the network's development is influenced by some degree of structural control. The areal aspects of the watershed point out elongated shape which possess lower erosion and sediment transport capacities and less prone to sudden floods but might require interventions to prevent sediment deposition in channels. The results of morphometric analysis along with slope map, aspect map and vegetation (NDVI) map are helpful for decision makers to implement soil and water conservation measures for sustainable management of the resources in watershed.