A framework of ecological sensitivity assessment for the groundwater system in the Mi River basin, Eastern China

As a critical natural resource, groundwater plays an important role in the stability of the geological environment and the balance of the ecosystem. The purpose of this study was to delineate the ecological sensitivity of the groundwater system in the Mi River basin of Eastern China and to provide a basis for future decision-makers to regulate groundwater. First, based on the available information and the specific situation of the study area, the evaluation index system of groundwater ecological sensitivity was constructed by selecting the influencing factors from four levels: groundwater system structure, natural environment, water resources, and social development. Then, the weights were assigned by the analytical hierarchy process (AHP) and entropy method, and the ecological sensitivity of the groundwater system was assessed by a geographical information system (GIS). The results showed that the ecologically moderately sensitive areas of the groundwater system were mainly distributed in the plain areas of Linqu and Qingzhou and the Shouguang area, accounting for 20.67% of the total area of the basin. The highly sensitive and extremely sensitive areas were distributed in the middle and lower reaches of the basin, accounting for 43.97% of the basin area. The insensitive and mildly sensitive areas were mainly located in the upstream areas of the watershed, accounting for 35.36% of the basin area. The results provide a basis for environmental protection in the Mi River basin and a reference for the protection and rational utilization of groundwater in the study area.