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Hydrologic response of catchments to precipitation: Quantification of mechanical carriers and origins of water.
- Source :
- Water Resources Research; Dec2011, Vol. 47 Issue 12, pW12515-W12515, 11p
- Publication Year :
- 2011
-
Abstract
- Precipitation-induced overland and groundwater flow and mixing processes are quantified to analyze the temporal (event and pre-event water) and spatial (groundwater discharge and overland runoff) origins of water entering a stream. Using a distributed-parameter control volume finite-element simulator that can simultaneously solve the fully coupled partial differential equations describing 2-D Manning and 3-D Darcian flow and advective-dispersive transport, mechanical flow (driven by hydraulic potential) and tracer-based hydrograph separation (driven by dispersive mixing as well as mechanical flow) are simulated in response to precipitation events in two cross sections oriented parallel and perpendicular to a stream. The results indicate that as precipitation becomes more intense, the subsurface mechanical flow contributions tend to become less significant relative to the total pre-event stream discharge. Hydrodynamic mixing can play an important role in enhancing pre-event tracer signals in the stream. This implies that temporally tagged chemical signals introduced into surface-subsurface flow systems from precipitation may not be strong enough to detect the changes in the subsurface flow system. It is concluded that diffusive/dispersive mixing, capillary fringe groundwater ridging, and macropore flow can influence the temporal sources of water in the stream, but any sole mechanism may not fully explain the strong pre-event water discharge. Further investigations of the influence of heterogeneity, residence time, geomorphology, and root zone processes are required to confirm the conclusions of this study. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00431397
- Volume :
- 47
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Water Resources Research
- Publication Type :
- Academic Journal
- Accession number :
- 75167305
- Full Text :
- https://doi.org/10.1029/2010WR010075