Quantifying the Spatial Variations of Hyporheic Water Exchange at Catchment Scale Using the Thermal Method: A Case Study in the Weihe River, China

Junlong Zhang,Jinxi Song,Bo Zhang,Yuanyuan Wang,Yuqi Wang,Yongqing Long,Yan Zhang

doi:10.1155/2017/6159325

Abstract

Understanding the dynamics of hyporheic water exchange (HWE) has been limited by the hydrological heterogeneity at large catchment scale. The thermal method has been widely used to understand water exchange patterns in a hyporheic zone. This study was conducted in the Weihe River catchment in Shaanxi Province, China. A conceptual model was developed to determine water transfer patterns, and a one-dimensional heat diffusion-advection equation was employed to estimate vertical fluxes of ten different segments in the hyporheic zone in various ten segments of the catchment. The amount of water exchange varied from 78.47 mm/d to 23.66 mm/d and a decreasing trend from the upstream to downstream of catchment was observed. The spatial correlation of variability between the water exchange and distance is 0.62. The results indicate that mountain’s topography trend is the primary driver influencing the distribution of river tributaries, and the water exchange amount has a decreasing trend from upstream to downstream of the main river channel.

Highlights

A hyporheic zone is an active ecotone which connects the surface water and groundwater [1]
Hyporheic water exchange (HWE) provides hydrogeological information about the interactions between groundwater and surface groundwater, whose function is crucial to the overall riverine ecosystem
Measurements of streambed temperature were collected at multiple depths at each location, the data were collected 15 minutes after the temperature kept stable, and temperature profiles in the hyporheic zone were plotted

Summary

Introduction

A hyporheic zone is an active ecotone which connects the surface water and groundwater [1]. It is characterized by the hydrological, chemical, biological [2], hydrogeological [3], and biogeochemical features [4]. Water exchange is a fundamental interest in the energy transport of a hyporheic zone [5]. The spatiality of water exchange at the stream-aquifer interface has important implications for the fate and transport of contaminants in river basins [8]. Hyporheic water exchange (HWE) provides hydrogeological information about the interactions between groundwater and surface groundwater, whose function is crucial to the overall riverine ecosystem

Objectives

Methods

Discussion

Conclusion