DOI: 10.5194/hess-23-2187-2019
论文题名: Spatial and temporal variability of groundwater recharge in a sandstone aquifer in a semiarid region
作者: Manna F. ; Murray S. ; Abbey D. ; Martin P. ; Cherry J. ; Parker B.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2019
卷: 23, 期: 4 起始页码: 2187
结束页码: 2205
语种: 英语
Scopus关键词: Aquifers
; Arid regions
; Catchments
; Chlorine compounds
; Evapotranspiration
; Groundwater pollution
; Groundwater resources
; Isotopes
; Precipitation (meteorology)
; Runoff
; Sandstone
; Stream flow
; Water levels
; Average annual precipitation
; Chloride mass balance
; Ground water recharge
; On site investigations
; Spatial and temporal resolutions
; Spatial and temporal variability
; Surface water and groundwaters
; Temporal and spatial
; Recharging (underground waters)
; bedrock
; calibration
; chemical mass balance
; chloride
; evapotranspiration
; groundwater pollution
; groundwater resource
; numerical model
; recharge
; sandstone
; semiarid region
; spatial resolution
; spatial variation
; temporal variation
; unsaturated flow
; vadose zone
; California
; Los Angeles [California]
; United States
英文摘要: With the aim to understand the spatial and temporal variability of groundwater recharge, a high-resolution, spatially distributed numerical model (MIKE SHE) representing surface water and groundwater was used to simulate responses to precipitation in a 2.16 km2 upland catchment on fractured sandstone near Los Angeles, California. Exceptionally high temporal and spatial resolution was used for this catchment modeling: hourly climate data, a 20m × 20m grid in the horizontal plane, and 240 numerical layers distributed vertically within the thick vadose zone and in the upper part of the groundwater zone. The finest practical spatial and temporal resolutions were selected to accommodate the large degree of surface and subsurface variability of catchment features. Physical property values for the different lithologies were assigned based on previous on-site investigations, whereas the parameters controlling streamflow and evapotranspiration were derived from calibration to continuous streamflow at the outfall and to average hydraulic heads from 17 wells. Confidence in the calibrated model was enhanced by validation through (i) comparison of simulated average recharge to estimates based on the applications of the chloride mass-balance method to data from the groundwater and vadose zones within and beyond the catchment, (ii) comparison of the water isotope signature (18O and 2H) in shallow groundwater to the variability of isotope signatures for precipitation events over an annual cycle, and (iii) comparison of simulated recharge time series and observed fluctuation of water levels. The average simulated recharge across the catchment for the period 1995-2014 is 16 mm yr-1 (4% of the average annual precipitation precipitation), which is consistent with previous estimates obtained by using the chloride mass balance method (4.2% of the average precipitation). However, one of the most unexpected results was that local recharge was simulated to vary from 0 to > 1000 mm yr-1 due to episodic precipitation and overland runoff effects. This recharge occurs episodically with the major flux events at the bottom of the evapotranspiration zone, as simulated by MIKE SHE and confirmed by the isotope signatures, occurring only at the end of the rainy season. This is the first study that combines MIKE SHE simulations with the analysis of water isotopes in groundwater and rainfall to determine the timing of recharge in a sedimentary bedrock aquifer in a semiarid region. The study advances the understanding of recharge and unsaturated flow processes and enhances our ability to predict the effects of surface and subsurface features on recharge rates. This is crucial in highly heterogeneous contaminated sites because different contaminant source areas have widely varying recharge and, hence, groundwater fluxes impacting their mobility. © Author(s) 2019. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162982
Appears in Collections: 气候变化与战略
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作者单位: Manna, F., G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, Guelph, ON, Canada; Murray, S., Matrix Solutions Inc., Guelph, ON, Canada; Abbey, D., Matrix Solutions Inc., Guelph, ON, Canada; Martin, P., Matrix Solutions Inc., Guelph, ON, Canada, Aqua Insight Inc., Waterloo, ON, Canada; Cherry, J., G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, Guelph, ON, Canada; Parker, B., G360 Institute for Groundwater Research, College of Engineering and Physical Sciences, University of Guelph, Guelph, ON, Canada
Recommended Citation:
Manna F.,Murray S.,Abbey D.,et al. Spatial and temporal variability of groundwater recharge in a sandstone aquifer in a semiarid region[J]. Hydrology and Earth System Sciences,2019-01-01,23(4)