characteristics of vertical hyporheic flux using a heat tracing method

• 1、State Key Laboratory Of Hydrology-Water Resources And Hydraulic Engineering, Hohai University, Nanjing 210098, Jiangsu

Abstract：Hyporheic flux is an important indicator which describes the amount of water that exchange between groundwater and stream water in hyporheic zone. It is of great importance for evaluating and developing water resources, as well as protecting ecosystem health. Temperature test is one of important methods in studying hyporheic flux for its high precision, low costs and convenience. We monitored the vertical stream temperature time series at various depth in DaWen River, Jining City, Shandong Province, and calculated the instantaneous hyporheic flux through the analytical solution of one-dimensional heat transport governing equation, through the DHR signal processing technology, by which the temperature fluctuation amplitude attenuation and phase delay can be obtained. Then we analyzed the dynamic characteristics and vertical distribution of hyporheic flux. The tests show that: Surface water and air temperature fluctuate approximately sinusoidally while the groundwater temperature maintain stable over time. During the monitoring period, the hyporheic flux fluctuated significantly, it ranged from 97L/m2?d to 321L/m2?d, and the hyporheic flux between different depth first decrease then increase. Its vertical distribution exists differences which variation with time.

Keywords： field test streambed temperature heat transport equation hyporheic flux heterogeneity characteristic