Regulation storage calculation and capacity evaluation of the underground reservoir in the groundwater overdraft area of northern China

Economic developments and a lack of surface water resources often result in the overexploitation of the groundwater, which lead to groundwater funnels, land subsidence, groundwater pollution and other environmental geological disasters. This phenomenon is particularly serious in developing countries. In such circumstances, to accurately calculate the regulation storage of the underground aquifers, evaluate the capacity of an underground reservoir and to restore the groundwater funnels are of great significance to the control of groundwater overexploitation at a global scale. In this paper, a calculation method for regulation storage of an underground reservoir is introduced, and the storage capacity is determined. First, the groundwater overdraft and hydrogeological materials are collected, and the geological structure to partition the hydrogeological units is analyzed. The representative drills are chosen, and profiles are drawn to describe the spatial distributions of the aquifers. Then, based on the lithology, the study area is divided into different hydrogeological units. Finally, the regulation storage is calculated using the volumetric method. In addition, using Surfer software, the second method is used to verify the calculation results. Through the establishment of a comprehensive evaluation index system for the underground reservoir regulation capacity, a gray correlation analysis of the index system is conducted, and the indices are reduced to six. Then, the regulation capacity is evaluated using the projection pursuit model. Taking Weifang of northern China as an example, the regulation storage is calculated and the regulation capacity is evaluated.