Impacts of model initialization on an integrated surface water - groundwater model

Handle URI:
http://hdl.handle.net/10754/348486
Title:
Impacts of model initialization on an integrated surface water - groundwater model
Authors:
Ajami, Hoori; McCabe, Matthew ( 0000-0002-1279-5272 ) ; Evans, Jason P.
Abstract:
Integrated hydrologic models characterize catchment responses by coupling the subsurface flow with land surface processes. One of the major areas of uncertainty in such models is the specification of the initial condition and its influence on subsequent simulations. A key challenge in model initialization is that it requires spatially distributed information on model states, groundwater levels and soil moisture, even when such data are not routinely available. Here, the impact of uncertainty in initial condition was explored across a 208 km2 catchment in Denmark using the ParFlow.CLM model. The initialization impact was assessed under two meteorological conditions (wet vs dry) using five depth to water table and soil moisture distributions obtained from various equilibrium states (thermal, root zone, discharge, saturated and unsaturated zone equilibrium) during the model spin-up. Each of these equilibrium states correspond to varying computation times to achieve stability in a particular aspect of the system state. Results identified particular sensitivity in modelled recharge and stream flow to the different initializations, but reduced sensitivity in modelled energy fluxes. Analysis also suggests that to simulate a year that is wetter than the spin-up period, an initialization based on discharge equilibrium is adequate to capture the direction and magnitude of surface water–groundwater exchanges. For a drier or hydrologically similar year to the spin-up period, an initialization based on groundwater equilibrium is required. Variability of monthly subsurface storage changes and discharge bias at the scale of a hydrological event show that the initialization impacts do not diminish as the simulations progress, highlighting the importance of robust and accurate initialization in capturing surface water–groundwater dynamics.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC)
Citation:
Impacts of model initialization on an integrated surface water - groundwater model 2015:n/a Hydrological Processes
Publisher:
Wiley-Blackwell
Journal:
Hydrological Processes
Issue Date:
1-Apr-2015
DOI:
10.1002/hyp.10478
Type:
Article
ISSN:
08856087
Additional Links:
http://doi.wiley.com/10.1002/hyp.10478
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorAjami, Hoorien
dc.contributor.authorMcCabe, Matthewen
dc.contributor.authorEvans, Jason P.en
dc.date.accessioned2015-04-02T13:53:04Zen
dc.date.available2015-04-02T13:53:04Zen
dc.date.issued2015-04-01en
dc.identifier.citationImpacts of model initialization on an integrated surface water - groundwater model 2015:n/a Hydrological Processesen
dc.identifier.issn08856087en
dc.identifier.doi10.1002/hyp.10478en
dc.identifier.urihttp://hdl.handle.net/10754/348486en
dc.description.abstractIntegrated hydrologic models characterize catchment responses by coupling the subsurface flow with land surface processes. One of the major areas of uncertainty in such models is the specification of the initial condition and its influence on subsequent simulations. A key challenge in model initialization is that it requires spatially distributed information on model states, groundwater levels and soil moisture, even when such data are not routinely available. Here, the impact of uncertainty in initial condition was explored across a 208 km2 catchment in Denmark using the ParFlow.CLM model. The initialization impact was assessed under two meteorological conditions (wet vs dry) using five depth to water table and soil moisture distributions obtained from various equilibrium states (thermal, root zone, discharge, saturated and unsaturated zone equilibrium) during the model spin-up. Each of these equilibrium states correspond to varying computation times to achieve stability in a particular aspect of the system state. Results identified particular sensitivity in modelled recharge and stream flow to the different initializations, but reduced sensitivity in modelled energy fluxes. Analysis also suggests that to simulate a year that is wetter than the spin-up period, an initialization based on discharge equilibrium is adequate to capture the direction and magnitude of surface water–groundwater exchanges. For a drier or hydrologically similar year to the spin-up period, an initialization based on groundwater equilibrium is required. Variability of monthly subsurface storage changes and discharge bias at the scale of a hydrological event show that the initialization impacts do not diminish as the simulations progress, highlighting the importance of robust and accurate initialization in capturing surface water–groundwater dynamics.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://doi.wiley.com/10.1002/hyp.10478en
dc.rightsArchived with thanks to Hydrological Processes. Copyright © 2015 John Wiley & Sons, Ltd.en
dc.titleImpacts of model initialization on an integrated surface water - groundwater modelen
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalHydrological Processesen
dc.eprint.versionPost-printen
dc.contributor.institutionSchool of Civil and Environmental Engineering; University of New South Wales; Sydney Australiaen
dc.contributor.institutionClimate Change Research Centre; University of New South Wales; Sydney Australiaen
dc.contributor.institutionConnected Waters Initiative Research Centre, University of New South Wales, Sydney, Australiaen
dc.contributor.institutionARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney, Australiaen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorMcCabe, Matthewen
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