Large-scale hydrological model is usually used to simulate river discharges. However, relatively little attention is paid to the simulation of river water depth. Water depth (water level) in rivers, as one of the most important factors, is very crucial in the coupled modeling of river and groundwater. In this paper, the spatial and temporal changes in river water depth are fully considered to couple with the groundwater in a spatially distributed hydrological model, WATLAC. The calculation was tested using the Panday and Huyakorn (P&H) tilted V-catchment. The results indicate that the model is effective in simulating the spatial and temporal variations in river water depth, and the corresponding water exchange between river and groundwater. Sensitivity simulation also indicates the effects of river bed roughness on water depth and consequently the water exchange volume between river and groundwater. The improved model is applicable to the areas where river-groundwater interactions are apparent, and can be used as an effective tool in surface water- groundwater management.%大尺度流域水文模型一般只模拟河道径流,对河流水深和流速并不关注.在进行河流-地下水相互作用模拟时,河流水深(水位)是一个重要因素,其时空变化及其对河流-地下水水量交换的影响应加以考虑.本文就流域分布式水文模型中河流水深的时空变化计算及其与地下水的实时耦合模拟进行了研究,提出了相应的计算方法,改进了大尺度水文模型WATLAC,并通过Ⅴ-型流域考题进行了检验.模拟结果显示,模型有效地模拟了Ⅴ-型流域的河流水深、地下水水位沿河道的时空变化以及河流与地下水的水交换量,揭示了河流-地下水相互作用关系在降雨过程中的变化规律及主控因子.此外就河床糙率对河流水深及河流与地下水间水交换量的影响做了模拟分析,发现河床糙率的改变将影响河流水深,从而进一步影响河流与地下水的水交换量.本文提出的算法较为真实地模拟了河流洪水演进过程及其对河流-地下水相互作用的影响,模型适用于河流-地下水相互作用明显的区域,可作为评估地表-地下水相互影响的有效计算工具.
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