Balancing practicality and hydrologic realism: a parsimonious approach for simulating rapid groundwater recharge via unsaturated-zone preferential flow
Water Resources Research
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
The impact of preferential flow on recharge and contaminant transport poses a considerable challenge to water-resources management. Typical hydrologic models require extensive site characterization, but can underestimate fluxes when preferential flow is significant. A recently developed source-responsive model incorporates film-flow theory with conservation of mass to estimate unsaturated-zone preferential fluxes with readily available data. The term source-responsive describes the sensitivity of preferential flow in response to water availability at the source of input. We present the first rigorous tests of a parsimonious formulation for simulating water table fluctuations using two case studies, both in arid regions with thick unsaturated zones of fractured volcanic rock. Diffuse flow theory cannot adequately capture the observed water table responses at both sites; the source-responsive model is a viable alternative. We treat the active area fraction of preferential flow paths as a scaled function of water inputs at the land surface then calibrate the macropore density to fit observed water table rises. Unlike previous applications, we allow the characteristic film-flow velocity to vary, reflecting the lag time between source and deep water table responses. Analysis of model performance and parameter sensitivity for the two case studies underscores the importance of identifying thresholds for initiation of film flow in unsaturated rocks, and suggests that this parsimonious approach is potentially of great practical value.
Suggested Citation
Mirus, B.B., Nimmo, J., 2013, Balancing practicality and hydrologic realism: a parsimonious approach for simulating rapid groundwater recharge via unsaturated-zone preferential flow: Water Resources Research, v. 49, no. 3, p. 1458-1465, https://doi.org/10.1002/wrcr.20141.
ISSN: 1944-7973 (online)
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Balancing practicality and hydrologic realism: a parsimonious approach for simulating rapid groundwater recharge via unsaturated-zone preferential flow |
| Series title | Water Resources Research |
| DOI | 10.1002/wrcr.20141 |
| Volume | 49 |
| Issue | 3 |
| Publication Date | March 12, 2013 |
| Year Published | 2013 |
| Language | English |
| Publisher | American Geophysical Union |
| Publisher location | Washington, D.C. |
| Contributing office(s) | Branch of Regional Research-Western Region |
| Description | 8 p. |
| Larger Work Type | Article |
| Larger Work Subtype | Journal Article |
| Larger Work Title | Water Resources Research |
| First page | 1458 |
| Last page | 1465 |