Morphometric Analysis tor Bangalore North Watersheds

摘要

Morphometric analysis of Bangalore North of Karnataka state has five watersheds namely South Pennar, Koramangala and Chalaghatta, Vrishabhavati, Hebbal valley, Arkavathi. It is carried out using 2 techniques namely RS and GIS. The morphometric parameters considered few of the analysis such as stream order, stream length, bifurcation ratio, drainage density, stream frequency, texture ratio, form factor, circulatory ratio, elongation ratio, relief ratio, length of overlandflow and basin shape. According to Strahler s method of ordering, the highest stream order obtained is 6th order for Arkavathi valleys and 5th order for Vrishabhavati, Hebbal valley and for South Pennar and Koramangala and Chalaghatta valley the highest stream order obtained is 4th order. The circularity ratio value for the South Pennar is 0.43, Koramangala and Chalaghatta is 0.33, Vrishabhavati is 0.35, Hebbal valley is 0.28, Arkavathi is 0.32. Its low, medium and high values are correlated with youth, mature and old stage of the cycle of the tributaries in watershed of the region. The elongation ratio value for the South Pennar is 0.75, Koramangala and Chalaghatta is 0.75, Vrishabhavati is 0.65, Hebbal valley is 0.65, Arkavathi is 0.63, which indicates that the watershed is elongated. The relative relief ratio for South Pennar is 0.0074, for Koramangala and Chalaghatta is 0.0043 and Vrishabhavati Valley is 0.0080, Hebbal valley is .0033, Arkavathi is 0.0122. The higher relative relief indicates that it is composed of resistant rock patches and lower relief ratio indicates less resistant patch of rocks.