Conference proceeding
Dynamic of groundwater flow and aquifer-river exchanges induced by flood events
American Geophysical Union Fall Meeting, Vol.2018
American Geophysical Union 2018 fall meeting
12/2018
Abstract
Rapidly rising river stages induced by flood events lead to considerable river water infiltration into unconfined aquifers and carry surface-borne solutes into hyporheic zones where is widely recognized as an important place for the biogeochemical activity in catchments. Existing studies for surface-groundwater exchanges induced by flood events usually limit to a river-aquifer cross-section that is perpendicular to river channels, and neglect groundwater flow in parallel with river channels. Surface-groundwater exchanges to a flood event are investigated with specific considerations of unconfined flow in direction that is in parallel with river channels. The groundwater flow is described by a two-dimensional Boussinesq equation and the flood event is described by a diffusive-type flood wave. Analytical solutions are derived and tested using the numerical solution. The results indicate that river water infiltrates into aquifers quickly during flood events, and mostly returns to the river within a short period of time after the flood event. However, the rest river water will stay in aquifers for a long period of time. The residual river water not only flows back to rivers but also flows to downstream aquifers. The one-dimensional model of neglecting flow in the direction parallel with river channels will overestimate heads at upstream aquifers and underestimate heads at downstream aquifers. The return flow induced by the flood event has a power-law form with time and has a significant impact on the base flow recession at early times. The solution can match the observed hydraulic heads peaks during flood events.
Details
- Title: Subtitle
- Dynamic of groundwater flow and aquifer-river exchanges induced by flood events
- Creators
- X. Liang - Southern University of Science and Technology, School of Environmental Science and Engineering Shenzhen CHN ChinaH. ZhanY. K. ZhangK. E. Schilling
- Resource Type
- Conference proceeding
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2018
- Conference
- American Geophysical Union 2018 fall meeting
- Publisher
- American Geophysical Union
- Alternative title
- AGU 2018 fall meeting
- Language
- English
- Date published
- 12/2018
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984384759602771
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