Sub-watershed prioritization inferred from geomorphometric and landuse/landcover datasets in Sari Watershed, Sumbawa Island, Indonesia

Sub-watershed prioritization based on erosion propensity plays essential roles in decision making in implementing management practices, especially in the sensitive semiarid regions. Geomorphometric and landuse/landcover datasets are crucial in terms of sub-watershed prioritization for integrated watershed management. Our study was held in Sari Watershed, Sumbawa Island, which needs to be given proper consideration of prioritizing sub-watersheds that need immediate handling. Integration of Principal Component Analysis (PCA) and Weighted Sum Approach (WSA) was used to determine the final sub-watershed prioritization. The use of PCA aimed to define significant parameters, while WSA was employed to determine the weights for significant parameters and calculate the compound values for priority ranking. The result showed that the integration of PCA and WSA was robust enough to define significant and more effective parameters with their weighted values for the sub-watershed prioritization. The adopted methodology in this study can be applied to different susceptibility in sub-watershed prioritization, such as a flash flood. This study also provides essential information for watershed managers to prioritize the program’s implementation in the prioritized sub-watershed.