北京西山泉域岩溶水系统特征探讨

摘要

北京西山地区岩溶地下水主要以相对独立的岩溶地下水系统进行循环,其水文地质条件、系统结构模式及其水资源的重要性等,在北方具有代表性.文章主要以北京西山鱼谷洞泉域岩溶水系统、黑龙关泉域岩溶水系统、玉泉山泉域岩溶水系统为研究对象,从岩溶含水层结构、地下水循环、地质构造等方面,总结出北京西山泉域岩溶水系统特征主要为:双层含水层结构、多个子系统构成且多点排泄、系统内岩溶水转化关系复杂多样、岩溶水富集带及系统边界集中在逆冲断层处.%Beijing is located in the north of the North China platform,where 3 second-order tectonic units meet,i.e.the Shanxi uplift,North China fault-depression,and Yanshan fold belt.In geomorphology,it lies at the conjunction of the Taihang Mountains,Yanshan Mountains and the North China plain.The study area is Xishan area of Beijing,part of the Taihangshan Mountains.The terrain is generally high in the northwest and low in the southeast,and the main rivers are the Dashi river and the Yongding river.The karst ground-water is dominated by cycles of the relatively independent karst groundwater system in the Xishan region of Beijing.The hydrogeological conditions,the system structure model and the importance of water resources of the karst groundwater in this area have certain representativeness in the north.It has abundant groundwa-ter resources and good water quality and is one of the important groundwater supply sources for Beijing City. The karst water in the area receives atmospheric precipitation,and seepage from the Yongding river and the Dashi river.At the same time,there is a transformation relationship between the partial area and the pied-mont covering loose pore groundwater and coal measure strata fissure groundwater.The resource elements of constitute are many and the transformation relationship is complex.The carbonate aquifers of the Xishan area include the thick layer of upper Proterozoic karst aquifer group,carbonate intercalation of the middle up-per Cambrian-lower Cambrian karst water-bearing rock group and the huge thick layer of Cambrian-Ordovi-cian carbonate water-bearing rock group,which cover most of karst aquifers in North China.According to the definition of karst water systems,the karst water bearing system,surface hydrology system,topography and geomorphology,geological structure and aquifer medium structure,previous study divided the karst wa-ter system in the Xishan area of Beijing into 6 systems,which are the Yuquanshan,Gaozhuang-Ganchi,Yu-gudong,Heilongguan,Mapao and Shangqingshui karst water systems.This paper takes the Yugudong, Heilongguan and Yuquanshan karst systems as the research objects.From the karst aquifer structure, groundwater circulation and geologic structure,we summarize the characteristics of karst water system as follows,double-layer aquifer structure,multiple subsystems and multiple points discharge,complicated and various karst water transformation relationships,and the concentration of karst water and system boundaries in thrust faults.