Numerical verification of hyporheic zone depth estimation using streambed temperature

- Numerical method to delineate hyporheic zone depth using CAD analysis was proposed.
- To evaluate adequacy of the proposed method, sensitivity analysis was performed.
- The hyporheic zone depth was little influenced by hyporheic water flux shapes.
- Estimated hyporheic zone depth of the method is comparable with that of tracer test.
- The proposed method has an advantage even when hyporheic flux shape is ambiguous.

SummaryThe hyporheic zone is the active region of groundwater and surface water mixing, and consequently, through which the contaminants released to surface water are transferred to groundwater. Because of the high energy demand and expense associated with the remediation of contaminated groundwater, it has become a matter of primary concern to find an efficient and cost-effective way to restore the contaminated groundwater. Therefore delineating the hyporheic zone is of vital importance for the prevention and management of groundwater contamination. This paper proposes a method to estimate the depth of the hyporheic zone using heat transfer analysis for a streambed. In order to assess the adequacy of the proposed method, the sensitivity of the results of heat transfer analyses to the hyporheic flux was evaluated. Due to the high sensitivity to the hyporheic zone depth, the heat transfer analysis was determined to be appropriate to delineate the hyporheic zone depth. The depth estimated from the heat transfer analysis was comparable with that from a conventional tracer test. The proposed method has an advantage over existing methods of determining the hyporheic zone depth due to the fact that it only requires field temperature measurements.