原木跌水结构对河流潜流带温度场的影响

Influence of log waterfall structure on temperature field of river hyporheic zone

为探究原木跌水结构对河流潜流带温度场的影响,应用有限元软件COMSOL Multiphysics构建了地表水地下水二维耦合模型,分析原木跌水结构的高度、间距及数量等参数变化对河流潜流带温度场的影响规律。结果表明:河道中原木跌水结构的添加会改变潜流带局部的压力分布,增加原木高度、间距和数量都会使河床压力最大值增大;随着原木跌水结构高度增加,原木下方区域温度受地表水水温的影响范围扩大;随着原木跌水结构间距和数量的增加,潜流带热缓冲作用增强。原木跌水结构设置参数的变化将不同程度影响潜流带温度场的变化和热缓冲作用,引起潜流带内部的热异质性,从而增加底栖生物和水生生境的多样性。

In order to explore the influence of log waterfall structure on temperature field of river hyporheic zone,a two-dimensional coupling model of surface water and groundwater was established by using the finite element software COMSOL Multiphysics,and the influence effects of log structure height,spacing and quantity on the temperature field was explored.The results show that the addition of log waterfall structure in the river can change the pressure distribution in the hyporheic zone,and increasing the height,spacing and the number of log structures can magnify the maximum pressure of the river bed.As the height of log waterfall structure increases,the temperature of the area below the logs is affected more widely by the surface water temperature.Thermal buffering of the hyporheic zone can be enhanced when the spacing and number of log waterfall structure increase.Variation of log structure parameters can affect the temperature field and thermal buffering in the hyporheic zone,resulting in thermal heterogeneity,which may increase the diversity of benthos and aquatic habitats.