河岸带潜流层温度示踪流速计算方法
Investigation on temperature tracer method calculated flow rate of hyporheic layer in riparian zone
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摘要: 为揭示低温水影响下的河岸带潜流层的温度场和流场分布特性,利用野外水温水位实时监测试验,研究河岸带潜流层温度场在不同季节、不同空间位置上的分布特性,并利用水温资料计算获得地下水流速。结果表明:河岸带潜流层温度场在夏季和冬季分别呈现出"上暖下冷"和 "上冷下暖"的温度分层现象;通过对温度示踪方法的4种计算方法进行分析比较,得到Hatch相位法计算的地下水流速具有较高的准确性,在2014年12月15—31日时段内流速大小为1.03×10-4~7.96×10-4m/s,在空间上,断面深度增加,地下水流速降低,且不同深度流速曲线接近平行。Abstract: The hyporheic layer is an important part of riparian zones. To reveal the distribution of temperature and flow field of hyporheic layers in riparian zones under the influence of low temperature water, a real-time monitoring test of temperature and water level was used to study the thermal structure of a hyporheic layer in different seasons and spatial locations, which could be used to calculate the groundwater velocity. Our results show that the temperature field of the hyporheic layer is characterized by seasonal reversal of thermal stratification: surface-warm and deep-cold during the summer and surface-cold and deep-warm during the winter. Among the four methods of calculation of the groundwater flow using temperature tracer, the Hatch phase method yielded the highest accuracy. The flow velocities ranged from 1.03×10-4 to 7.96×10-4m/s during the period of Dec. 15—31, 2014, which decreased with the increasing depth in section and the groundwater flow velocity curves were close to parallel.