Estimation of the Leakage Rate from a Riverbed According to the Data of Diurnal Temperature Oscillations in Riverbed Sediments (based on the Example of the Heihe River, Inner Mongolia, China)

Abstract

Estimation of the leakage rate from riverbeds is an important task to quantify the interaction between surface and ground waters and to perform effective management of water resources, especially under arid climate conditions, where leakage from riverbeds helps to preserve the existence of riparian ecosystems. One of the methods for estimating the leakage rate from a riverbed is the use of diurnal temperature oscillations in riverbed sediments. The data from monitoring the temperature of the sediments in the lower reaches of the Heihe riverbed (northwestern China) are used to calculate the leakage rate from the riverbed. The results of the leakage rate calculations are compared to the data obtained by solving an inverse problem using the one-dimensional model of heat and moisture transfer in the riverbed sediments according to the data of the annual observation cycle. Good agreement of the calculated and model leakage rates is observed when the temperature sensors, whose data are used for the calculation of the leakage rates, are spaced at a significant distance (≥0.3 m) and at a depth greater than 0.3 m.