Effects of Streambed Conductance on Stream Depletion

Water

Greg Lackey³  Roseanna M. Neupauer³  John Pitlick¹  Philip A. Brunner² 

[1]Department of Geography, University of Colorado, Guggenheim 110, 260 UCB, Boulder, CO 80309-0428, USA

[2] E-Mail:

[3]Department of Civil, Environmental, and Architectural Engineering, University of Colorado, ECOT 441, 428 UCB, Boulder, CO 80309-0428, USA

[4] E-Mail

[5]Department of Civil, Environmental, and Architectural Engineering, University of Colorado, ECOT 441, 428 UCB, Boulder, CO 80309-0428, USA

[6] E-Mail:

关键词: stream depletion;    streambed conductance;    groundwater modeling;   

DOI  :  10.3390/w7010271

来源: mdpi

【 摘 要 】

Stream depletion, which is the reduction in flow rate of a stream or river due to the extraction of groundwater in a hydraulically connected stream-aquifer system, is often estimated using numerical models. The accuracy of these models depends on the appropriate parameterization of aquifer and streambed hydraulic properties. Streambed conductance is a parameter that relates the head difference between the stream and aquifer to flow across the stream channel. It is a function of streambed hydraulic conductivity and streambed geometry. In natural systems, streambed conductance varies spatially throughout the streambed; however, stream depletion modeling studies often ignore this variability. In this work, we use numerical simulations to demonstrate that stream depletion estimates are sensitive to a range of streambed conductance values depending on aquifer properties. We compare the stream depletion estimates from various spatial patterns of streambed conductance to show that modeling streambed conductance as a homogeneous property can lead to errors in stream depletion estimates. We use the results to identify feasible locations for proposed pumping wells such that the stream depletion due to pumping from a well within this feasible region would not exceed a prescribed threshold value, and we show that incorrect assumptions of the magnitude and spatial variability of streambed conductance can affect the size and shape of the feasible region.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.