Identification and Allocation of Ecological Compensation Space Based on Ecological Risk Assessment: A Case Study of Dongting Lake Eco-economic Zone

Scientific identification of ecological compensation space and the determination of ecological compensation timing are necessary prerequisites for the formulation of ecological compensation policy. The lack of well-established ecological risk assessment in the existing ecological compensation research undermines the timeliness and accuracy of regional ecological compensation policy, posing difficulties to the effective protection and management of the regional eco-systems. In this study, a research framework for the spatial identification of ecological compensation based on ecological risk assessment is constructed, which evaluates the value of ecosystem services, ecological supply, and ecological risk in the region in turn, calculating the priority index of ecological compensation based on regional economic conditions to identify the priority area needing ecological compensation. In addition, it proposes a method to determine the distribution weight of ecological compensation for each unit. This work studies Dongting Lake Eco-Economic Zone and the results show that: (1) The overall value of ecosystem services in the research area increased by 33.37 billion yuan, a 7.6% growth from 2010 to 2020, primarily due to the increase in wetland area; (2) The service supply level and ecosystem service risk level are rated as 0 to 5 points, and the spatial distribution of ecosystem service supply level shows a decreasing pattern from east-west to inward circles, with the central lake area prominent and the northern part lower; While the ecosystem service risk level is higher in the southeast and the lowest in the central lake area. In general, the ecological supply and ecological risks in the eastern and southern parts of the study area are at a high level. Therefore, their ecological compensation should be given priority; (3) The study area is divided into four types of ecological compensation areas, namely, priority compensation area, secondary compensation area, general compensation area, and potential compensation area. Among them, Anhua County, Pingjiang County, Shimen County, and Taoyuan County in the eastern and southern parts of the study area are assigned the largest weights as priority compensation areas, at 0.182, 0.129, 0.108, and 0.110, respectively. The allocation weights of the secondary and the general compensation area are lower, with the total weights being 0.332 and 0.139, respectively. Potential compensation areas do not participate in the distribution of ecological compensation. The proposed methods are helpful in delineating the priority areas of ecological compensation more accurately and comprehensively, determining the distribution weight of ecological compensation, and guiding the scientific management of regional ecosystems.