管道-裂隙岩溶含水介质非均质性的水文效应

非均质性是含水介质的固有特性之一,对自然界的水文循环,地球浅层地质演变具有积极的贡献,因此是评价复杂地下水系统时所面临困难的最根本原因。通过SWMM模型对水文过程进行了室内模拟试验,研究了管道-裂隙岩溶含水介质非均质性对系统水文过程的影响。结果表明,管道尺寸、含水介质空隙度和地下水与地表水水量交换系数对系统出口处的水位和流量过程的影响均较小,但管道尺寸对地下水的最高水位有一定的控制作用;含水介质空隙度对地下水水位的增长和消落过程有一定影响;地下水与地表水水量交换系数则是对地下水水位的变化率和其能达到的最大值有着重要的影响。模拟结果证实,利用SWMM模型模拟管道-裂隙含水系统的水文过程是有效的。

Hydrologic Effects Caused by the Heterogeneity of Karstic Conduit-Fissure Medium

The heterogeneity is one essential property of karstic medium, resulting in the complicated hydrologic cycle and shallow geologic evolution. Moreover, the heterogeneity of medium also leads to the high difficulty for the evaluation of groundwater flow system and solute transportation. The SWMM developed by EPA (U.S. Environmental Protection Agency) was used in this study to simulate the hydrologic process conducted at the laboratory. The hydrologic effects of the heterogeneity were discussed through the calibrated SWMM model. The results indicate that SWMM model is appropriate to model the karstic hydrologic process for the conduit-fissure medium. The conduit size, the medium void and the exchange coefficient of groundwater and surface interaction has slight effect on the water level and discharge of the outlet of drainage area. However, the conduit size controls the highest groundwater level, the magnitude of medium void can change the process of groundwater increasing and decreasing, and the exchange coefficient has significant effects on the change speed of groundwater level and the highest groundwater level.