Monitoring temporal patterns of vertical hyporheic flux via distributed temperature sensors

Abstract. Hyporheic exchange is of great significance for evaluating and developing water resources, as well as protecting ecosystem health. Temperature monitoring is one of the powerful tools for recognizing the hyporheic flux with high precision, low cost and great convenience. The streambed temperature at different depths (0 to 1.00 m), and the air and stream water temperatures at Dawen River, Jining City, were monitored using distributed temperature sensors (DTS). The temperature series were used to estimate the hyporheic flux through the analytical solution of the governing one-dimensional heat transport equation. The temporal patterns of flux along the vertical profile were analysed. The results indicated that surface water and air temperatures fluctuated approximately sinusoidally, and the groundwater temperature was relatively stable over time. The hyporheic flux at different depths showed different temporal patterns. Moreover, the dynamic curves of hyporheic flux were depth-dependent and probably controlled by the stream water level and groundwater field.