Quantitative evaluation of sustainable development ability of deep buried geothermal water coupled with key index factors

Scientific evaluations of the sustainable development ability of deep-buried geothermal water are essential to fully utilizing these resources while simultaneously minimizing negative environmental effects. However, due to the multi-source and variability of accumulated information in the process of geothermal water development, the precise identification of spatial differences in sustainable development capabilities is still in the exploratory stage. Taking geothermal water of thermal reservoirs with buried depths of 1000-1200 m and 1200-1400 m of downtown Kaifeng City China as an example, the exploitation potential, well distribution density, geothermal gradient, water level decline rate, recharge volume, and specific yield are selected as index factors. The weights of index factors are determined based on the gray correlation analysis method, and the sustainable development ability of the geothermal water is quantitatively evaluated using fuzzy variable set theory. Our research shows that the geothermal water resources of the 1000-1200 m deep thermal reservoir in Kaifeng can be divided into three sustainable development ability zones: 'weakest', 'medium', and 'strong'. Moreover, the 1200-1400 m deep thermal reservoir can also be divided into three sustainable development ability zones: 'weakest', 'weak', and 'strongest'. This research work provides a direction for the rational development and scientific protection of geothermal water.