thumbnail

A method for estimating spatially variable seepage and hydrualic conductivity in channels with very mild slopes

Hydrological Processes

By:
, , , , ,
DOI: 10.1002/hyp.9545

Links

Abstract

Infiltration along ephemeral channels plays an important role in groundwater recharge in arid regions. A model is presented for estimating spatial variability of seepage due to streambed heterogeneity along channels based on measurements of streamflow-front velocities in initially dry channels. The diffusion-wave approximation to the Saint-Venant equations, coupled with Philip's equation for infiltration, is connected to the groundwater model MODFLOW and is calibrated by adjusting the saturated hydraulic conductivity of the channel bed. The model is applied to portions of two large water delivery canals, which serve as proxies for natural ephemeral streams. Estimated seepage rates compare well with previously published values. Possible sources of error stem from uncertainty in Manning's roughness coefficients, soil hydraulic properties and channel geometry. Model performance would be most improved through more frequent longitudinal estimates of channel geometry and thalweg elevation, and with measurements of stream stage over time to constrain wave timing and shape. This model is a potentially valuable tool for estimating spatial variability in longitudinal seepage along intermittent and ephemeral channels over a wide range of bed slopes and the influence of seepage rates on groundwater levels.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A method for estimating spatially variable seepage and hydrualic conductivity in channels with very mild slopes
Series title:
Hydrological Processes
DOI:
10.1002/hyp.9545
Volume
28
Issue:
1
Year Published:
2014
Language:
English
Publisher:
Wiley
Publisher location:
Hoboken , NJ
Contributing office(s):
Nevada Water Science Center
Description:
11 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
51
Last page:
61