黔中丘峰盆地区岩溶找水及开发技术——以贵阳市乌当区地下水机井工程为例

Karst water prospecting and development technology in karst peak cluster basin area,central Guizhou:A case study of groundwater pump well project in Wudang district,Guiyang

为解决当地农村群众饮水安全问题,探讨黔中丘峰盆地区岩溶找水及开发技术,开展了贵阳市乌当区地下水机井工程。在对区内地形地貌、地质构造、水文地质等情况调查的基础上,初步圈定出沿构造等可能布设机井的地下水富集地带,并通过高密度电阻率法在靶区布设物探剖面,根据电性差异查明主径流带的走向及埋深状况,进一步确定机井位置。最终通过钻探施工和抽水试验,查明区内含水层岩溶发育程度及其富水性,并成功施工6口探采结合井,为当地居民饮水提供了安全水源。黔中丘峰盆地为裸露岩溶区,主要含水岩组为寒武系娄山关群白云岩、灰质白云岩,地下水赋存条件较差;区内岩溶中等发育,以溶蚀裂隙为主,局部裂隙、溶洞发育地带和断层等储水构造富水性强,为地下水的富集地段,也是机井布设的首选位置。

Guizhou Province is located in the mountainous area of southwest China,where the carbonate rocks are widely distributed.However,the uneven distribution of karst groundwater has brought great difficulties to the prospecting and development of karst groundwater,resulting in the lack of drinking water in some karst areas.In order to solve the problem of drinking water safety of rural people,the groundwater pumping well project in Wudang district of Guiyang City was carried out to study the karst water prospecting and development technology in karst peak cluster basin area,central Guizhou Province.Firstly,on the basis of the survey of topography,geological structure and hydrogeology in the area,the groundwater enrichment zones that may be laid out along the structure are delineated preliminarily.Secondly,the high density resistivity method was used to lay out geophysical profiles in the target area,and the trend and buried depth of the main runoff zone were identified according to the difference of electrical properties,so as to further determine the location of the well.Finally,through drilling construction and pumping test,the karst development degree and water abundance of aquifer in the area were fount out,and six wells were successfully constructed,which provided safe water source supply for local residents.The results show that karst peak cluster basin area in central Guizhou is an exposed karst area,and the main water-bearing rock groups are dolomite and calcite dolomite of Cambrian Loushanguan group,and the storage conditions of groundwater are poor.Karst is moderately developed in the area,the karst morphology is mainly dissolved fissures,local fissures,karst caves,faults and other water storage structural areas with strong water abundance,which is the groundwater enrichment area and is also the preferred location for the layout of pump well.This project has accumulated some experience for water prospecting and well drilling in similar karst water shortage area in southwest China.