Quantification of Water Supply Services in the Shiyang River Basin Using the HSPF Model

Water supply services are a focal point of research on aquatic ecosystem services, and the quantification of supply services is also a key aspect of water supply service studies. This paper characterizes the availability of water supply in the study area using the Available Water Supply Index to investigate the situation of available water supply in an arid region under human intervention. It establishes a quantitative framework for assessing the reliability and vulnerability of ecosystem service delivery related to available water supply, utilizing reliability and vulnerability indices. These analyses address two primary questions: first, the reliability of regional available water supply services when meeting the most basic ecological water needs, and second, the vulnerability of available water supply services when striving to meet increased production demands in the region. This study focuses on the Shiyang River Basin and employs the Hydrological Simulation Program-FORTRAN (HSPF) model for runoff simulation, evaluating the model's applicability using criteria such as residual sum of squares and correlation analysis. Building on the subdivision of sub-basins within the Shiyang River Basin and adjustments for extra water diversion data, this research conducts a spatiotemporal analysis of available water supply in the Shiyang River Basin for the year 2017 and addresses the two aforementioned questions.