Morphometric analysis of watersheds of Kangra region of Indian Himalaya for assessing their fluvial erosion susceptibility 1* 2 3 (original) (raw)

Drainage Morphometric analysis was carried out to assess the fluvial erosion susceptibility of watersheds in Kangra region of Himachal Pradesh in India. The topographic maps and SRTM DEM were used as inputs for digitization of drainages and preparation of watershed boundaries, respectively. The linear, aerial and relief parameters of drainages were calculated for all the watersheds and weightages were assigned to them to derive Composite Weightage Values (CWV). Consequently, by way of grouping these values, the watersheds were categorized in to four classes such as low, medium, high and very high watershed erosion susceptibility. The analyses were conducted in Geographic Information System environment which, resulted in 10 watersheds in the study area, namely, 1B1A1, 1B1A2, 1B1B3, 1B1B4, 1B1B5, 1B1B6, 1B1B7, 1B1C8, 1B1C9 and 1B1C10. Among these, the watersheds 1B1A2 (Chakki-Jabban) and 1B1B5 (Dehar) were concluded as most susceptible to stream erosion followed by 1B1A1, 1B1B3, 1B1B7, 1B1B4-1B1B6-1B1C10, 1B1C9 and 1B1C8. The correlation of CWV with morphometric parameters showed that the high stream frequency, coarser texture, high relief and low length of overland flow control the drainage pattern in the region. It was also observed that among land use/ land cover, agriculture land is major factor governing soil erosion. Geologically, it is influenced mainly by the Quaternary Alluvium and unconsolidated rock formations of the terrain. It was revealed that 17.78 % of the study area is prone to very high erosion, 21.54 % is prone to high erosion, 43.11 % is prone to medium erosion, and 17.57 % area is prone to low erosion. It is therefore suggested that the soil and water conservation measures are required in the watersheds to control the fluvial erosion.