岩溶多重介质含水系统泉流量特征的研究对岩溶水资源的开发利用具有重要的指导意义。利用自主研发的裂隙-管道介质物理模型,模拟岩溶裂隙-管道介质的泉流量衰减过程,设计多组试验探讨不同因素对泉流量衰减过程的影响。试验结果表明,衰减过程随释水介质的变化分为3个亚动态;衰减系数的大小主要受泉口大小、补给状态、含水介质初始蓄水状态的影响。基于物理试验结果,通过Visual MODFLOW软件结合等效渗透系数法建立符合物理模型机制的水流数值模型,对数值模型进行参数灵敏度分析,研究模型内部结构对泉流量过程的影响。结果表明,排水沟的综合水力传导系数对泉流量过程影响最大,垂直层面裂隙等效渗透系数的影响次之,管道等效渗透系数的灵敏度再次之,泉流量过程对层面裂隙等效渗透系数最不敏感。
Study on the spring flow characteristics in karst multi-media water system is essential for the de-velopment and utilization of karst water resources. To discuss the factors influencing the discharge attenua-tion process, a physical analog is built to simulate the spring flow attenuation in karst fissure-conduit me-dia and more groups of experiments are designed. It’s shown that recession curve is divided into three seg-ments along with the change of water release media. The value of recession coefficients is related to the change of spring mouth, supply situation and initial water storage condition. Base on the physical experi-ments, a flow numerical model is established through the Visual MODFLOW software using the equivalent hydraulic conductivity method, which is able to simulate the spring flow attenuation process accurately. Pa-rameter sensitivity analysis is carried out on the numerical model to analyze the effect of the model inter-nal structure on spring flow attenuation process. The results show that the effect to the attenuation process from big to small in turn is:the conductance of drain, the equivalent hydraulic conductivity of vertical fis-sures, the equivalent hydraulic conductivity of conduit and the equivalent hydraulic conductivity of horizon-tal fissures.