Effects of spatial grid resolution on river flow and surface inundation simulation by physically based distributed modelling approach

Grid-based distributed hydrological models are considered to be a very effective flood modelling tool for basin-wide flood risk analysis because of their capabilities of simulating river and surface inundations at high spatio-temporal resolutions by taking advantages of grid-based data from meteorological models, radar and satellite remote sensing. Selecting an appropriate grid size is critically important for any application of a grid-based model, which requires proper understanding of effects of grid sizes on simulated outcomes. The paper presents the outcomes of a study conducted to analyse the effects of grid resolution on simulated river peak flows and surface inundation in two selected river basins using a process-based distributed hydrological model. The outcomes show that grid resolution significantly affects the simulated river peak flows and surface inundation characteristics. In both cases, it has been found that the effects are mainly caused by changes of the topographic parameters as a result of changes of grid sizes. The reduction of average surface slope with the increase of grid size affects the simulated surface inundation extents and heights. There is a threshold resolution of digital elevation model (DEM) in the simulated flood inundation and beyond that the model outcomes become arbitrary. Averaged topographic values at coarse resolution beyond this threshold level do not represent any characteristics of locally elevated topographic features such as dykes, highways, etc. and their influence on flood inundation characteristics can be no more captured by the model. Copyright © 2008 John Wiley & Sons, Ltd.

[1]  APPLICATION OF IIS DISTRIBUTED HYDROLOGICAL MODEL (IISDHM) IN NAKHON SAWAN CATCHMENT, THAILAND , 1998 .

[2]  D. Montgomery,et al.  Digital elevation model grid size, landscape representation, and hydrologic simulations , 1994 .

[3]  K. Beven,et al.  Sensitivity to space and time resolution of a hydrological model using digital elevation data. , 1995 .

[4]  William W. Doe,et al.  Introduction to Soil Erosion and Landscape Evolution Modeling , 2001 .

[5]  Rudi Hessel,et al.  Effects of grid cell size and time step length on simulation results of the Limburg soil erosion model (LISEM) , 2005 .

[6]  D. Dutta,et al.  A COUPLED RIVER AND INUNDATION MODELING SCHEME FOR EFFICIENT FLOOD FORECASTING , 2003 .

[7]  E. O'Loughlin.  Prediction of Surface Saturation Zones in Natural Catchments by Topographic Analysis , 1986 .

[8]  Lawrence W. Martz,et al.  Grid size dependency of parameters extracted from digital elevation models , 1994 .

[9]  Zhi-Yong Yin,et al.  A cross-scale comparison of drainage basin characteristics derived from digital elevation models , 1999 .

[10]  K. Beven,et al.  A physically based, variable contributing area model of basin hydrology , 1979 .

[11]  S. Herath,et al.  Development of IIS Distributed Hydrological Model (IISDHM) and its Application in Chao Phraya River Basin, Thailand , 1997 .

[12]  Murugesu Sivapalan,et al.  Scale and scaling in hydrology , 2004 .

[13]  D. Dutta,et al.  A mathematical model for flood loss estimation , 2003 .

[14]  Jens Christian Refsgaard,et al.  Effect of grid size on effective parameters and model performance of the MIKE‐SHE code , 2002 .

[15]  Katumi Musiake,et al.  Flood inundation simulation in a river basin using a physically based distributed hydrologic model , 2000 .

[16]  Dennis P. Lettenmaier,et al.  Application of a GIS-based distributed hydrology model for prediction of forest harvest effects on peak stream flow in the Pacific Northwest , 1998 .

[17]  K. Kristensen,et al.  A MODEL FOR ESTIMATING ACTUAL EVAPOTRANSPIRATION FROM POTENTIAL EVAPOTRANSPIRATION , 1975 .

[18]  P. Braun,et al.  The problem of scaling in grid-related hydrological process modelling. , 1997 .

[19]  D. Wolock,et al.  Effects of digital elevation model map scale and data resolution on a topography‐based watershed model , 1994 .

[20]  Eric F. Wood,et al.  Effects of Digital Elevation Model Accuracy on Hydrologic Predictions , 2000 .

[21]  N. Farajalla,et al.  Capturing the essential spatial variability in distributed hydrological modelling: Infiltration parameters , 1995 .