岩溶地下水系统演化的数值模拟

为了研究岩溶地区泉域系统演化过程及对泉流量进行预测,耦合了渗流模型和岩溶动力模型,对均质和非均质2种条件下泉域系统进行了溶蚀演化模拟。从模拟结果上可以看出,均质含水系统初期水位变化较小,中后期下降明显,而非均质含水系统初期下降明显,中后期水位稳定;在张开度方面,非均质模型在相同时段内张开度的最在值却比均质系统要大4～5 cm。2个泉域系统的泉流量都经过了初期较小,中后期迅速增大的过程,只是增大的时间和每个时间点的泉流量不同,非均质系统增大时间更早,流量更大,分别用指数函数和多项式函数来拟合了均质和非均质系统泉流量过程曲线。研究结果为岩溶地下水系统演化模拟提供了一个新方法,同时也为岩溶地区地下水资源评价研究提供了科学依据。

Numerical Simulation of the Evolution of Karst Groundwater System

In order to study the evolution of karst spring system and predict the spring flow, we simulated the evolution of karst dissolution in homogeneous and heterogeneous aquifer system by coupling seepage model and karst dynamic model. It’s found that the water level of the homogeneous aquifer system changes slightly at initial stage and decreases significantly at initial stage at the middle-late stage, while the initial water level of the heterogeneity aquifer system decreased significantly and remains stable at the middle-late stage. In terms of the fracture aperture, the maximum value of the aperture during the same period in the heterogeneous model is 4-5cm larger than that in the homogeneous model. Spring flow of the two systems is small at the initial stage and increases rapidly at the middle-late stage, but the time of increasing and spring flow at each time point are different. The flow of heterogeneous system increases earlier and the flow is larger. The exponential function and polynomial function are employed to fit the curves of the spring flow process in the homogeneous and heterogeneous system. The research provides a new way for simulation of evolution of the karst groundwater system, and also provides scientific basis for groundwater resources evaluation in the karst area at the same time.