摘要:
岩溶含水系统存在不规则的裂隙网络和管道结构,由于贮水空间的差异,导致水流运移的多变性和水动力参数的复杂难测。基于泉流量过程线的分析技术能够很好地识别岩溶系统中的管道流和裂隙流。文章将泉流量分为3个组成部分:前期蓄水量、快速径流和慢速径流,其中快速径流和慢速径流视为两线性并联水库,建立了前期降雨和瞬时单位线之间的识别函数,识别降雨在岩溶不同空隙类型中的水量分配系数,并将该函数模型应用到后寨地下河岩溶小流域。模拟结果表明,上游到下游前期蓄水量呈增加趋势,而水量进入管道中的分配系数分别为0.84,0.6以及0.48,呈现递减趋势,说明岩溶裂隙结构越往下游越发育。模型计算出的泉流量曲线与实测值相比,NSE 达到90%以上,模拟效果理想。
Abstract:
Karst aquifers contain irregular networks of pores,fissures,fractures and conduits of various sizes and forms.Such structure with significant physical and geometrical heterogeneity causes complex hydraulic conditions and spatial and temporal variability of hydraulic parameters.To solve this problem,the composi-tion transfer function for karst aquifers is established by the analysis of the spring hydrograph.This hydro-graph is composed of the accumulative storage rainfall,channel flow,and quick flow based on the character-istic of the karstic aquifer.A linear convolution integral model is applied to distinguish the quick flow and slow flow components of a karst spring hydrograph.This method is tested by a case application to the Houzhai underground river in southwestern China.Simulation of the data of the spring flow and the rainfall using this approach shows that the accumulative storage capacity increases from the upstream to the down-stream,and the proportions of conduit flow are 0.84,0.6 and 0.48,respectively.It means that the increas-ing networks of fissures develop to downstream of the river basin.The NSE from the model calculation is o-ver 90% compared with the real measurement values.
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