昆明吴家营岩溶水系统边界的水文地球化学分析

Hydrogeochemical analysis of Wujiaying karst ground-water system boundaries,Kunming

西南岩溶水系统边界条件复杂,其中水头隔水边界在水动力条件改变的情况下具有不稳定的隔水特性。文章以昆明吴家营岩溶地下水系统为例,通过水化学组分动态序列图解法、数理统计法及水文地球化学模拟等方法对研究区边界特性进行了研究。研究结果表明该岩溶水系统水动力条件丰水季优于枯水季,并存在与边界外发生水力联系的越流通道;丰水季时岩溶槽谷区地下水在高水力梯度的驱动下向下绕过玄武岩隔水层,通过下部阳新灰岩对系统内岩溶水进行越流补给,枯水季受深部滞流阻水影响,越流补给现象不明显;由此得出此类水头边界的隔水特性会随水动力条件的改变而具有动态响应特征。研究成果对当地岩溶水资源量的评价和合理开发利用提供科学依据。

In Southwest China, the hydaulic boundaries of the karst groundwater system are very complex, partly because the water-resisting property of the constant head （Type Boundary） is unstable. In this paper, Wujiaying karst groundwater system in Kunming is studied. Three methods have been used to study the hydrogeochemistry and hydrogeological boundaries, i. e. dynamic groundwater chemical analysis, mathematical statistics and hydrogeochemical modeling. The results confirm that the groundwater flow in this area is more active and may link to other groundwater system in wet season. Due to the high hydraulic head difference, groundwater in the karst valley area can be driven to pass through the karst aquifer under the confining bed and recharge the Wujiaying karst groundwater system via leakage. While in dry season, this type of hydraulic connection is not common. It is concluded that the water-resisting property of this type of boundary could have dynamic response to the change of the hydraulic condition in the karst groundwater system. This research has significant value in the context of local groundwater resource evaluation and sustainable development.