Impact of DEM Resolution and Spatial Scale: Analysis of Influence Factors and Parameters on Physically Based Distributed Model

Abstract

Physically based distributed hydrological models were used to describe small-scale hydrological information in detail. However, the sensitivity of the model to spatially varied parameters and inputs limits the accuracy for application. In this paper, relevant influence factors and sensitive parameters were analyzed to solve this problem. First, a set of digital elevation model (DEM) resolutions and channel thresholds were generated to extract the hydrological influence factors. Second, a numerical relationship between sensitive parameters and influence factors was established to define parameters reasonably. Next, the topographic index (TI) was computed to study the similarity. At last, simulation results were analyzed in two different ways: (1) to observe the change regularity of influence factors and sensitive parameters through the variation of DEM resolutions and channel thresholds and (2) to compare the simulation accuracy of the nested catchment, particularly in the subcatchments and interior grids. Increasing the grid size from 250 m to 1000 m, the TI increased from 9.08 to 11.16 and the Nash-Sutcliffe efficiency (NSE) decreased from 0.77 to 0.75. Utilizing the parameters calculated by the established relationship, the simulation results show the same NSE in the outlet and a better NSE in the simple subcatchment than the calculated interior grids.

Applicability assessment of the CASCade Two Dimensional SEDiment (CASC2D‐SED) distributed hydrological model for flood forecasting across four typical medium and small watersheds in China

“…), and output the results (discharge, water depth, and sediment transport) with user‐defined multiple spatial–temporal resolutions (Molnar & Julien, ). Previous studies on the predictive capacity of the CASC2D‐SED model suggested that this model is particularly useful for hydrological simulation in medium and small watersheds (usually less than 3,000 km 2 ) (Molnar & Julien, ; Zhang, Li, Saifullah, Li, & Li, ).…”

Sensitivity Analysis of the MOHID-Land Hydrological Model: A Case Study of the Ulla River Basin

“…The analyzed parameters/processes as well as the variations imposed on model inputs were defined based on previous calibrations of the MOHID-Land model for different watersheds [22,[25][26][27]. Additionally, the calibration processes performed on similar physically based models were also considered [49][50][51][52][53][54]. Thus, sixteen parameters/processes influencing water dynamics at the catchment scale were analyzed:…”

“…These authors found no statistically significant differences in the accuracy of DTMs varying between 10 and 2 m resolution when simulating streamflow and sediment yield using the WEPP model in a considerably smaller basin than the Ulla River catchment (the Centonara catchment in northern Italy, 1.92 km 2 ). Also, Zhang et al [51] and Nazari-Sharabian et al [53] showed the influence of the DTM resolution on the calibration of streamflow simulations using different physically based models.…”

Review and critical analysis on digital elevation models

“…The parameters, such as soil, vegetation, precipitation, and underlying surface conditions are greatly influenced by DEM resolution. Zhang (2016) revealed DEM resolution plays an important role in the simulation process where higher DEM resolution results in the more accurate representation of terrain features. This is due to topography, which causes significant variations in solar irradiation over short distances.…”