Evaluation of the potential groundwater resources in Tai’an urban-Jiuxian karst water system, Shandong Province

Tai’an urban-Jiuxian karst water system is located at the foot of the southern Mount Tai in Shandong Province, it is a monoclinal structure water-bearing system with two water sources in urban and Jiuxian. It is higher in the north than in the south, covering an area of 112 square kilometers. The water-bearing stratum of the system are predominatly Quaternary, Cambrian and Ordovician, with a large area of Archaean igneous rocks of Taishan group in the south and the north. The tectonic unit is a part of Luxi anticline in the western Tailai fault subsidence basin. Faults include the NE-trending Taishan, Culaishan and Jiezhuang faults, and NW-trending Honggou, Panghe and Daidaoan faults. The water bearing formation includes a pore aquifer in uncosolidated Quaternary sediments and a karst bedrock fracture aquifer in the Cambrian- Ordovician carbonates. The groundwater is obviously affected by precipitation and artificial exploitation. By the end of 2012, the exploitation of groundwater was 52 thousand cubic meters per day, approaching the allowable with drawal limit of 57.9 thousand cubic meters, which is the equilibrium of exploitation and rechargement. Relying on the previous data, changes in the karst water recharge due to the barrage of Muwen River was studied. Results indicate that the system still has potential for exploitation due to recharge by surface water, and about 20 thousand cubic meters water per day are allowed to be exploited in the water-bearing system.