The Effects of Surface Water Velocity on Hyporheic Interchange

作     者：Timothy Sickbert Eric W. Peterson 

作者机构：1School of Geology Noble Research Center Oklahoma State University Stillwater USA 2Department of Geography-Geology Illinois State University Normal USA Department of Geography-Geology Illinois State University Normal USA 

出 版 物：《Journal of Water Resource and Protection》 (水资源与保护（英文）)

年 卷 期：2014年第6卷第4期

页      面：327-336页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Hyporheic Zone Bernoulli Equation Venturi Effect Geomorphology Fluvial Groundwater/Surface Water Interaction Streamflow 

摘      要：When evaluating hyporheic exchange in a flowing stream, it is inappropriate to directly compare stream stage with subsurface hydraulic head (h) to determine direction and magnitude of the gradient between the stream and the subsurface. In the case of moving water, it is invalid to ignore velocity and to assume that stage equals the net downward pressure on the streambed.? The Bernoulli equation describes the distribution of energy within flowing fluids and implies that net pressure decreases as a function of velocity, i.e., the Venturi Effect, which sufficiently reduces the pressure on the streambed to create the appearance of a downward gradient when in fact the gradient may be upward with stream flow drawing water from the subsurface to the surface. A field study correlating the difference between subsurface head and stream stage in a low-gradient stream indicates that the effect is present and significant: shallow subsurface head increases less quickly than stage while deeper subsurface head increases more quickly. These results can substantially improve conceptual models and simulations of hyporheic flow.