Evaluating Water and Soil Resource Carrying Capacity from the Production–Living–Ecological Space Perspective: A Case Study of Hunan Province, China

Quantifying water and soil resource (WSR) carrying capacity is crucial for sustainable regional development. However, humid hilly regions like Hunan Province remain understudied, facing ecological vulnerability despite abundant water resources. This study constructs a comprehensive evaluation index system based on the Production–Living–Ecological Space (PLES) framework and applies an improved entropy weight technique for order preference by similarity to ideal solution (TOPSIS) method; a coupling coordination model among production, living, and ecological space subsystems; and an obstacle degree model to annual-scale data from 2011 to 2022 for Hunan’s 14 prefecture-level cities. The results show the following: (1) The overall WSR carrying capacity index increased from 0.28 in 2011 to 0.52 in 2022, indicating a continuous improvement in carrying capacity during the study period. Spatially, the carrying capacity is higher in central and eastern regions and lower in western and southern areas, with most cities falling into low, relatively low, or medium categories. (2) The coupling coordination degree among the three PLES subsystems improved but remained in a transitional stage (0.30–0.45), indicating unbalanced development. (3) The top five obstacle factors are water yield modulus, length of water supply pipelines, ecological water use rate, gross domestic product (GDP) per capita, and per capita water resources—with the ecological water use rate exceeding 19% in every year of the study period. These findings highlight the need to coordinate production, living, and ecological subsystems to improve WSR carrying capacity. Targeted strategies, including efficient water use, optimized resource allocation, and ecological protection, are recommended for sustainable water–soil resource management in Hunan Province.