渭河下游户县段垂向潜流通量动态特征研究

Abstract

河流的潜流带是一个特殊的水文地质体，有其独特的水动力机制和生态作用。潜流通量是其中一项重要指标，在一定程度上能够反映地表水和地下水的相互作用关系。本文采用波动振幅衰减法计算潜流通量，利用温度示踪技术，重点研究潜流通量动态变化特征及潜流通量在时间空间上的分布特征。以陕西西安户县渭河段为研究区，进行河床浅层沉积物潜流通量的计算。结果表明：监测时段内研究区主要为河水补给地下水，不同深度平均潜流通量变化范围为9.7 × 10−7~2.9 × 10−6 m/s。潜流通量随潜流带深度增大，潜流通量数值随时间波动幅度减小。潜流通量数值垂向分布上随时空变化具有差异性。 Hyporheic zone is a special hydrogeological body, which has unique hydrodynamic mechanism and ecological function; hyporheic flux, one of the important indexes, can reflect the relationship between surface water and groundwater. The study uses wave amplitude attenuation method to calculate the hyporheic zone vertical hyporheic flux. On the basis of temperature tracing theory and calculation methods, we study the relationship between hydroheic conditions and variation characteristics as well as temporal and spatial distribution characteristics of subsurface flux. We calculated the amount of hydrodynamic exchange in the hyporheic zone of the Huxian County section in Weihe River as a case study. Results show that surface water recharges groundwater mainly in this research area. Mean hyporheic flux changed from 9.7 × 10−7 m/s to 2.9 × 10−6 m/s. As the depth increases, fluctuation range of hyporheic flux became small over the time. The vertical distribution of subsurface flux varies with time and space.