Research on the Ecological Compensation Mechanism in Hanjiang River Basin of China Based on Four‐Party Evolutionary Game

ABSTRACT Existing research on watershed ecological compensation has predominantly focused on the game dynamics between water supply and receiving areas, or between upstream and downstream regions. Notably, however, numerous contemporary watersheds are intertwined with inter‐basin water transfer projects, necessitating the simultaneous consideration of both natural hydrological connections and artificial engineering‐induced relationships. The Hanjiang River Basin was elucidated in this study through the establishment of a four‐party evolutionary game model, encompassing the central government, upstream water source area, middle and downstream regions, and water‐receiving area. Employing simulation software, the impacts of initial probabilities—defined as the likelihood of proactively selecting supervision, protection, or compensation strategies—and key parameters on model stability and equilibrium were examined. Results demonstrate that under the stable strategy combination (i.e., the central government conducts daily supervision, the upstream area implements ecological protection, and both the middle and downstream regions and water‐receiving area fulfill compensation obligations), the probability and speed of stabilization of the four‐party model increase with the initial probability of any participant adopting the target strategy. Supervision costs were found to significantly influence the central government's regulatory strategy; therefore, effective monitoring of ecological compensation requires the reduction of such costs, which can be achieved by enhancing horizontal compensation mechanisms and optimizing the compensation structure. Conversely, punitive measures were shown to effectively regulate the behaviors of all stakeholders, thereby promoting fairness and order throughout the ecological compensation process in the Hanjiang River Basin.