Vol. 12, Issue 8 (2023)

Author(s):
Gangadhar Namwade, MM Trivedi, Mukesh Kumar Tiwari, GR Patel and Bhukya Srinivas

Abstract:
Knowledge of watershed geometry and geomorphic condition is a prerequisite for developing a watershed management plan. use of morphometric analysis has increased significantly in studies dealing with watershed management mainly for the identification of natural drainage systems and prioritization of sub-watersheds. This study employed morphometric analysis and introduced a hybrid model by integrating geo-informatics and multivariate statistical Modeling to identify the most significant erosion-prone morphometric parameters and prioritize the sub-watersheds of the Hathmati River watershed in Sabarkantha district of Gujarat. This study applied two statistical methods, i.e., principal component analysis (PCA) and PCA's weighted sum model (PCA-WSM) based on correlation matrix approach, to prioritise the sub-watersheds. Boundaries of the sub-watersheds and drainage network were determined in geographic information system using digital elevation model. Then, PCA was applied to define the significant morphometric parameters, while the WSA was employed to determine the weights for the significant parameters and calculate the compound values for priority ranking. During prioritization of sub-watersheds using compound factor values, higher priority was assigned to sub watersheds which yielded lowest compound factor and vice-versa. The drainage density varies from 0.41 km²/km^-1 to 1.14 km²/km^-1, it is observed that the higher density for the sub watershed SW7 and lower for the SW1. the higher drainage density indicates high runoff potential. Sub-watersheds SW6 to SW7 covering an area of 405 km² were noted to have highest priorities for soil erosion conservation measures; SW2, SW3 and SW4 had medium priorities; and SW1, and SW5 were assessed with lowest priorities. and the results showed that the integration of PCA and WSA was robust enough to define the significant and most effective parameters with their weighted values for the sub-watershed prioritization. It is anticipated that the prioritization of sub-watersheds would be useful to planners, decision makers, and relevant stakeholders for implementation of soil and water conservation interventions for sustainable natural resources management within watershed.