Morphometric analysis of milli watershed of Raichur district using GIS techniques

摘要

The study area is situated in the North-Eastern dry zone (Zone-2 of Region-1) of Karnataka at 160 11’ North latitude and 770 16’ East longitudes to 160 12’ North latitude and 770 17’East longitudes. The drainage network of milli watershed was delineated using ESRI Software Arc GIS 9.2.The parameters required for morphometric analysis are computed using ArcInfo and ArcView softwares. The drainage pattern of the study area is dendritic with stream order IV and lower streams order dominated in the milli watershed. The bifurcation ratio reflecting geological and tectonic characteristics of the watershed was estimated as 4.27 indicate that the watershed has suffered less structural disturbance and the drainage pattern has not been distorted by structural disturbance. The drainage density of watershed is 3.39 km/sq km indicates the closeness of spacing of channels, thus providing a quantitative measure of the average length of stream channel for the whole watershed. The values of form factor and circulatory ratio of milli watershed indicate that the milli watershed is approaching towards the circulatory shape. The values of length of overland flow of the milli watershed indicate that the areas are associated with high run-off and less infiltration. The low value of ruggedness number indicates that watershed is having gentle slope. Hence, it is concluded that GIS techniques proved to be a competent tool in morphometric analysis.