The Influence Study Of Underground Mining On Groundwater In Hilly Area

Underground mining project affects groundwater flow system through changing the runoff way, and the water yield of mine is the most main manifestation. Water yield prediction of mine is the foundation of both the influence study of underground mining on groundwater flow system, and high-efficient use of mining water resource, and its accuracy is very important for mining producing security. Therefore, carrying out the influence study of underground mining on groundwater flow based on water yield prediction of mine, has certain theoretical significance and practical value.Longqiao iron ore and Mabianshan iron ore are located in hilly area in Anhui province where the loose sediments of Quaternary System are thin. Around mining area, the population density is large, and villagers’domestic water is mostly from underground water. In recent years, a large amount of underground water is discharged during the process of underground mining. Groundwater drainage, especially for the fracture cavern confined water, may results in inevitable influence on the water level decreasing of the overburden aquifer, level of Quaternary aquifer decreasing, and even affects the safety of drinking water and ecological environment. Therefore, carrying out the influence study of underground mining on groundwater flow has practical significance to making groundwater protecting plan and offset measures.In this article, Longqiao and Mabianshan underground mining was taken as an example. Based on each stage reconnaissance result of mineral deposit, the hydrogeological characteristics of study area were analyzed systematically. Based on comprehensive acquaint the hydrogeological conditions, hydrogeological supplement survey was carried on combining with the request of research objective. According to primary water-filling factors of mineral deposit and influence objects, hydrogeological conditions were generalized, the hydrogeological conceptual model and mathematical model were established. The groundwater flow numerical simulation model was established by the means of Visual Modflow, water yield of mine was predicted, the results showed:the primeval water yield of mine would be2800m3/d when Longqiao iron ore was independent mined,10309m3/d when Mabianshan iron ore was independent mined,12244m3/d when they were mutual interferential, and the corresponding stabilized water yield of mine would be2200m3/d,3150m3/d, and4400m3/d. And then, the influence of Longqiao and Mabianshan mining on regional groundwater flow system was quantificationally analysed.