Numerical simulation analysis of groundwater in karst area and comparison of mining schemes

Numerical simulation is one of the effective ways to solve the problem of groundwater exploitation evaluation. In order to develop groundwater resources in karst collapse areas with a safe and efficient way, takes the karst area of Linyi City, Shandong Province as an example, and fully understands the law of groundwater recharge, migration and distribution in karst areas according to hydrogeological investigation and analysis. On this basis, a reasonable simulation range is selected, a numerical model is established, and a numerical prediction analysis of multi-scheme groundwater dynamic evolution is carried out, based on which the optimal mining scheme is analyzed and evaluated. The results show that in scheme 1, the risk of karst collapse is relatively high. The water level of the numerical observation hole drops below 39.9 m on the 1 279th day, 1 644th day, 2 019th day and 3 105th day, which will lead to the risk of karst collapse. The scheme 2 is safer. The water level in the dry period is close to the elevation of limestone roof, which not only meets the standard of groundwater exploitation and utilization potential, but also ensures the safety of ecological geological environment, therefore, scheme 2 is recommended. In the mining process, the water level in the warning area should be below the elevation of bedrock roof to avoid karst collapse. This paper can provide reference for scientific mining of similar collapse areas.