岩溶地下水特点与研究热点

Features and Hotspots in Karst Groundwater

岩溶区覆盖了超过20%的地壳面积,岩溶水作为供水水源发挥的作用举足轻重。然而,岩溶介质的非均质性十分突出,是有不同水力性质的双重介质系统,使得岩溶地下水系统入渗过程亦具有二元性。岩溶区降水、地表水和地下水间的关系十分密切、转化规律呈复杂的非线性关系。这使得岩溶地下水系统的水文过程、流速和排泄范围易受外界影响而多变。岩溶泉流量变化具有明显的尺度效应和多重分形特征,流量构成复杂多变。同时,受多变的岩溶水文过程和生物地球化学作用的影响,岩溶地下水系统的水化学变化对环境十分敏感。因此,传统方法不能直接应用于岩溶地区的水文研究,水文研究常见的困难在岩溶区被成倍放大。目前,岩溶水文研究相对滞后。我国岩溶类型多样,在国际上有范例性。在岩溶水文过程和岩溶地下水CO_2-H_2O-CaCO_3系统的研究中取得进展。岩溶地下水系统水文过程对全球变化的响应和反馈,岩溶地下水资源和水环境,以及岩溶水文系统模拟等方面将是未来的研究热点。

Karst covers more than 20% of lithosphere area. Karst groundwater resource is a vital water resource. However, a karst water-bearing system is a kind of dual media with distinct hydraulic properties, of which heterogeneity is significant and two mechanisms of surface water infiltration are of the same importance. The connection across precipitation, surface water and karst groundwater is very close. And the conversion among them is nonlinear with considerable complexity. Hydrologic processes, flow rates and the discharging area are readily impacted by the changing environment in a karst groundwater flow system. Discharges of karst springs are of scale effect and multi-fractal characteristics. And the composition of discharge is complicated and changeable. Furthermore, hydrogeochemical characteristics of karst groundwater are sensitive to the changing environment determined by variable hydrologic processes of karst and biogeochemical reactions. Therefore, traditional geohydrologic methods can＇t be applied directly in a karst basin and the common difficulties in hydrologic researches tend to be amplified. At present, researches in karst hydrology are relatively laggard. The karst in China is type diversity and representative all over the world. Studies in regard to karst hydrologic processes and the karst CO_2-H_2O-CaCO_3 system have made progress in China. In future, responses and feedbacks to the global change, water resource and environment, and hydrologic processes modeling of a karst groundwater flow system are the potential researching hotspots.