Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach

Based on the Representative Elementary Watershed (REW) approach, the modelling tool REWASH (Representative Elementary WAterShed Hydrology) has been developed and applied to the Geer river basin. REWASH is deterministic, semi-distributed, physically based and can be directly applied to the watershed...

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Main Authors: G. P. Zhang, H. H. G. Savenije
Format: Article
Language:English
Published: Copernicus Publications 2005-01-01
Series:Hydrology and Earth System Sciences
Online Access:http://www.hydrol-earth-syst-sci.net/9/243/2005/hess-9-243-2005.pdf
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author G. P. Zhang
H. H. G. Savenije
author_facet G. P. Zhang
H. H. G. Savenije
author_sort G. P. Zhang
collection DOAJ
description Based on the Representative Elementary Watershed (REW) approach, the modelling tool REWASH (Representative Elementary WAterShed Hydrology) has been developed and applied to the Geer river basin. REWASH is deterministic, semi-distributed, physically based and can be directly applied to the watershed scale. In applying REWASH, the river basin is divided into a number of sub-watersheds, so called REWs, according to the Strahler order of the river network. REWASH describes the dominant hydrological processes, i.e. subsurface flow in the unsaturated and saturated domains, and overland flow by the saturation-excess and infiltration-excess mechanisms. The coupling of surface and subsurface flow processes in the numerical model is realised by simultaneous computation of flux exchanges between surface and subsurface domains for each REW. REWASH is a parsimonious tool for modelling watershed hydrological response. However, it can be modified to include more components to simulate specific processes when applied to a specific river basin where such processes are observed or considered to be dominant. In this study, we have added a new component to simulate interception using a simple parametric approach. Interception plays an important role in the water balance of a watershed although it is often disregarded. In addition, a refinement for the transpiration in the unsaturated zone has been made. Finally, an improved approach for simulating saturation overland flow by relating the variable source area to both the topography and the groundwater level is presented. The model has been calibrated and verified using a 4-year data set, which has been split into two for calibration and validation. The model performance has been assessed by multi-criteria evaluation. This work represents a complete application of the REW approach to watershed rainfall-runoff modelling in a real watershed. The results demonstrate that the REW approach provides an alternative blueprint for physically based hydrological modelling.
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spelling doaj.art-a47679c495c1478fb0322cccdf956af92022-12-22T03:55:14ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382005-01-0193243261Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approachG. P. ZhangH. H. G. SavenijeBased on the Representative Elementary Watershed (REW) approach, the modelling tool REWASH (Representative Elementary WAterShed Hydrology) has been developed and applied to the Geer river basin. REWASH is deterministic, semi-distributed, physically based and can be directly applied to the watershed scale. In applying REWASH, the river basin is divided into a number of sub-watersheds, so called REWs, according to the Strahler order of the river network. REWASH describes the dominant hydrological processes, i.e. subsurface flow in the unsaturated and saturated domains, and overland flow by the saturation-excess and infiltration-excess mechanisms. The coupling of surface and subsurface flow processes in the numerical model is realised by simultaneous computation of flux exchanges between surface and subsurface domains for each REW. REWASH is a parsimonious tool for modelling watershed hydrological response. However, it can be modified to include more components to simulate specific processes when applied to a specific river basin where such processes are observed or considered to be dominant. In this study, we have added a new component to simulate interception using a simple parametric approach. Interception plays an important role in the water balance of a watershed although it is often disregarded. In addition, a refinement for the transpiration in the unsaturated zone has been made. Finally, an improved approach for simulating saturation overland flow by relating the variable source area to both the topography and the groundwater level is presented. The model has been calibrated and verified using a 4-year data set, which has been split into two for calibration and validation. The model performance has been assessed by multi-criteria evaluation. This work represents a complete application of the REW approach to watershed rainfall-runoff modelling in a real watershed. The results demonstrate that the REW approach provides an alternative blueprint for physically based hydrological modelling.http://www.hydrol-earth-syst-sci.net/9/243/2005/hess-9-243-2005.pdf
spellingShingle G. P. Zhang
H. H. G. Savenije
Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach
Hydrology and Earth System Sciences
title Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach
title_full Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach
title_fullStr Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach
title_full_unstemmed Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach
title_short Rainfall-runoff modelling in a catchment with a complex groundwater flow system: application of the Representative Elementary Watershed (REW) approach
title_sort rainfall runoff modelling in a catchment with a complex groundwater flow system application of the representative elementary watershed rew approach
url http://www.hydrol-earth-syst-sci.net/9/243/2005/hess-9-243-2005.pdf
work_keys_str_mv AT gpzhang rainfallrunoffmodellinginacatchmentwithacomplexgroundwaterflowsystemapplicationoftherepresentativeelementarywatershedrewapproach
AT hhgsavenije rainfallrunoffmodellinginacatchmentwithacomplexgroundwaterflowsystemapplicationoftherepresentativeelementarywatershedrewapproach