Exploring Ecosystem Service Trade-Offs and Synergies for Sustainable Urban Watershed Management in Indonesia – A Case Study of the Citarum River Basin, West Java, Indonesia

Understanding the relationships among ecosystem services (ESs) are crucial for sustainable watershed management. Current studies on ESs often focus on mapping individual services, but there is limited research on the trade-offs and synergies degree (TSD) among them. The objectives of this study are: (i) to map multi-year data for three Ess: water yield (WY), carbon stock (CS), and soil conservation (SC); (ii) to examine the TSD among these ESs; and (iii) to identify the variables that influence TSD. The Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model was used to map WY, SC, and CS in the Citarum Watershed, Indonesia. Multiscale geographically weighted regression (MGWR) model was employed to explore the relationships between the factors influencing TSD. The results indicate that (1) both WY and CS experienced similar downward trends, decreasing by 18.37% and 2.89% from 2000 to 2010, and by 15.01% and 4.98% from 2010 to 2020, respectively. In contrast, SC increased by 10.60% from 2000 to 2010 and by 12.03% from 2010 to 2020. (2) The TSD analysis revealed significant variations in trade-offs and synergies within the Citarum watershed, with the most prominent TSD occurring between WY and SC (approximately 64%). (3) The driving factors of TSD include vegetation, topography, climate, and social factors, contributing 34.51%, 31.99%, 20.92%, and 11.58%, respectively, to the WY-SC trade-off. The novelty of this research lies in its integration of TSD with the MGWR model, providing valuable insights into the complex spatial relationships between TSD and its driving factors. These findings offer important contributions to sustainable watershed management.