Vol. 9, Issue 1 (2021)

According to Strahler’s system of stream ordering, the natural drainage system of watershed was classified and the main stream was found as 4^th order stream. It showed that, the maximum frequency in case of first order stream was 34 and that for second, third and fourth order streams was found to be 8, 2 and 1, respectively. The stream length ratio (R_L) was estimated to be 0.28 and 1.31 for II/I and III/II orders, respectively. The increasing trend in R_L from lower order to higher order indicated matured geomorphic stage and change from one order to another order in stream length ratio indicated late youth stage of geomorphic development of streams. In the present study, bifurcation ratio (R_b) varied from 2.0 to 4.25 with an average of 3.42, which indicates that the value of R_b was not the same from one order to next order. The higher value of R_b indicated strong structural control on the drainage pattern. This showed its usefulness for hydrograph shape for watersheds similar in other respect. The bifurcation ratio between first and second order streams indicated the nature of head ward erosion. In the present case, the head ward erosion was moderate as bifurcation ratio was 4.25. The drainage density was found to be 3.48 km/km². Lower drainage density of the basin (3.48 km/km²) indicates towards course drainage pattern. The course texture gives more time for overland flow and hence to ground water recharge. The circulatory ratio (R_c), elongation ratio (R_e) and form factor (R_f) was estimated to be 0.45, 0.60 and 0.28 respectively, indicating them to be elongated in shape and suggesting flatter peak flow for longer duration. In sub-watershed GR-3 the stream length followed Horton’s law. But in sub-watersheds GR-1, GR-2 and GR-4, the stream segments of various orders showed variation from general observation. This change may indicate flowing of streams from high altitude, litho logical variations and moderately steep slopes. The stream length ratio between different sub-watersheds showed an increasing trend from lower order to higher order indicating their mature geomorphic stage in sub-watersheds. The prioritization was carried out by assigning ranks to the individual indicators and a compound value (Cp) was calculated. Watersheds with highest Cp were of low priority while those with lowest Cp were of high priority. Sub-watershed GR-4 with a compound parameter value of 2.22 received the highest priority, which consists of steep slopes, high drainage density, high stream frequency, low form factor and low elongation ratio and the sub-watersheds GR-1and GR-2 both have same C_p value as 2.55 received second priority. The sub-watershed GR-3 had highest C_p value as 2.67 received last priority. Highest priority indicated the greater degree of erosion in the particular sub-watershed and it became potential area for applying soil conservation measures. Thus soil conservation measures can first be applied to sub-watershed GR-4 and then to the other sub-watersheds depending upon their priority.