山东省泰安市城区-旧县岩溶水系统地下水资源潜力评价

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

山东省泰安市城区-旧县岩溶水系统位于山东省中部的泰山南麓,为单斜构造式岩溶含水系统,由城区和旧县两个水源地组成,地势总体北高南低,面积约112km2。含水系统内地层以新生界第四系和古生界寒武、奥陶系为主,此外,在南部和北部分布有较大面积的太古界泰山岩群火成岩。本区在构造单元上属鲁西台背斜的一部分,泰莱断陷盆地之西半部。区内断裂构造发育,主要有NE向的泰山断裂、徂徕山断裂及结庄断裂,NW向的洪沟断裂、滂河断裂、岱道庵断裂。含水系统包括第四系松散岩类孔隙含水岩组和寒武-奥陶系碳酸盐岩类裂隙岩溶含水岩组,地下水动态受降水及人工开采影响明显。截止2012年底,地下水日均开采量为5.2万m3,接近系统允许开采量5.79万m3,处于采补平衡状态。本文在充分利用前人研究资料的基础上,通过对牟汶河修建拦河坝,河水位抬高引起的岩溶水补给条件变化的研究,确定该含水系统尚具有开采潜力,其潜力主要来源于地表水入渗补给。通过研究计算,目前该含水系统还具有约2万m3/d的开采潜力。

Tai’an urban-Jiuxian karst water system is located at the foot of the southern Mount Tai in Shan-dong Province,it is a monoclinal structure water-bearing system with two water sources in urban and Jiux-ian.It is higher in the north than in the south,covering an area of 1 1 2 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-Or-dovician 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 allowa-ble with drawal limit of 57.9 thousand cubic meters,which is the equilibrium of exploitation and recharge-ment.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.