Impact of grid resolution on the integrated and distributed response of a coupled surface–subsurface hydrological model for the des Anglais catchment, Quebec

Abstract

Digital elevation models (DEMs) at different resolutions (180, 360, and 720 m) are used to examine the impact of different levels of landscape representation on the hydrological response of a 690-km2 catchment in southern Quebec. Frequency distributions of local slope, plan curvature, and drainage area are calculated for each grid size resolution. This landscape analysis reveals that DEM grid size significantly affects computed topographic attributes, which in turn explains some of the differences in the hydrological simulations. The simulations that are then carried out, using a coupled, process-based model of surface and subsurface flow, examine the effects of grid size on both the integrated response of the catchment (discharge at the main outlet and at two internal points) and the distributed response (water table depth, surface saturation, and soil water storage). The results indicate that discharge volumes increase as the DEM is coarsened, and that coarser DEMs are also wetter overall in terms of water table depth and soil water storage. The reasons for these trends include an increase in the total drainage area of the catchment for larger DEM cell sizes, due to aggregation effects at the boundary cells of the catchment, and to a decrease in local slope and plan curvature variations, which in turn limits the capacity of the watershed to transmit water downslope and laterally. The results obtained also show that grid resolution effects are less pronounced during dry periods when soil moisture dynamics are mostly controlled by vertical fluxes of evaporation and percolation

Effects of Data and Model Simplification on the Results of a Wetland Water Resource Management Model

“…This is because there are fewer, larger hydrological response units, which leads to simplification within the wetland. Similar effects were found by Sulis et al [42] for different resolutions of DEM and responses of a hydrological model. Another aspect is the larger usable water storage obtained by modifying the DEM, especially for variant 8 ( Figure 7).…”

Impact of earthquake-induced-landslides on hydrologic response of a steep mountainous catchment: a case study of the Wenchuan earthquake zone

“…Taking into account the impact of landslides on the local topography, the mesh was different after the earthquake. The DEM after the earthquake (in 2011) with a resolution of 30 m was used to modify the elevation rather than simulate the hydrologic response, to reduce the error of hydrological simulation caused by the resolution of DEM (Zhang and Montgomery, 1994;Sulis et al, 2011). The remote sensing image was also used for the modification.…”

“…Over the past decades, the impact of the underlying surface conditions on the runoff formation has been documented, mainly focusing on the influence of vegetation changes (Shi and Chen, 2004;Bari et al, 2005), urbanization (Campana and Tucol, 2001), as well as the resolution of terrain data used in the models (Sulis et al, 2011). However, the impact of the underlying surface conditions induced by the landslides on the hydrologic response at the catchment scale is not yet clear.…”

Effects of watershed subdivision level on semi-distributed hydrological simulations: case study of the SLURP model applied to the Xiangxi River watershed, China

“…This is partly attributed to the increasing availability of digital elevation models (DEMs) and terrain analysis tools over a broad range of scales (Wise 2007, Orlandini and Moretti 2009, Eldrandaly and AbuZaid 2011, Mao et al 2011, Sulis et al 2011. Meanwhile, the use of hydrological models raises issues related to spatial parameterization and watershed discretization.…”