Enhancing Watershed Management through Seasonal Water Yield Modelling using InVEST (Case Study: Rawa Pening Catchment Area)

Abstract

Located in the upstream of the Tuntang Watershed in Indonesia, Rawa Pening catchment is a significant watershed, recognized as one of the nation’s priority watersheds. Evaluating the catchment’s sustainability relies on its water yield, a crucial determinant in guaranteeing a steady water supply, thereby enhancing water security. This study aims to achieve the following objectives: 1.) To utilize the InVEST model for the estimation of temporal water yield potential within the Rawa Pening Catchment Area from 2018 to 2022, 2.) To assess the accuracy of the InVEST model in temporally estimating water yields within the Rawa Catchment Area, and 3.) To investigate the spatial distribution and characteristics of water yield in the Rawa Pening Catchment Area between 2018 and 2022.The results of the study demonstrate significant trends: The peak rate of flow was recorded in November 2022, reaching 645.87 mm/month, and the minimum rate was seen in July 2018, measuring only 0.82 mm/month. The model calibration shows a substantial correlation value of 0.95, a PMARE Index of 12.84%, and a determination coefficient of 0.9011. Despite minor variations, the InVEST model’s accuracy remains substantial due to the high interconnectivity of variables. Various elements, including rainfall patterns, land use practices, soil hydrological characteristics, and threshold flow accumulation, influence the spatial dynamics of quick flow.