Abstract
The scale effects of digital elevation models (DEM) on hydrology and nonpoint source (NPS) pollution simulations have been widely reported for natural watersheds but seldom studied for urban catchments. In this study, the scale effect of DEM data on the rainfall-runoff and NPS pollution was studied in a typical urban catchment in China. Models were constructed based on the DEM data of nine different resolutions. The conventional model performance indicators and the information entropy method were applied together to evaluate the scale effects. Based on the results, scaling effects and a resolution threshold of DEM data exist for urban NPS pollution simulations. Compared with natural watersheds, the urban NPS pollution simulations were primarily affected by the local terrain due to the overall flat terrain and dense sewer inlet distribution. The overland process simulation responded more sensitively than the catchment outlet, showing prolonged times of concentration for impervious areas with decreasing DEM resolution. The diverse spatial distributions and accumulation magnitudes of pollutants could lead to different simulation responses to scaling effects. This paper provides information about the specific characteristics of the scale effects of DEM data in a typical urban catchment, and these results can be extrapolated to other similar catchments as a reference for data collection.
Highlights
Nonpoint source (NPS) pollution has become an important concern for urban water environment management as point source pollution has gradually been controlled [1]
We focused on the scaling effect of digital elevation models (DEM) data on the simulation of urban NPS
For the rainfall-runoff simulation in the R-5 model, the Nash–Sutcliffe efficiency coefficient (NSE) values exceeded 0.5 except for the 0831 rainfall, indicating that the hydrology simulation performance was at an acceptable level
Summary
Nonpoint source (NPS) pollution has become an important concern for urban water environment management as point source pollution has gradually been controlled [1]. Distributed urban NPS pollution models are common tools for studying the overland NPS pollution process as they possess physically-based routing algorithms and spatially heterogeneous structures [4]. For these models, high-resolution spatial input data, such as GIS maps for topography and geography features, and drainage data are generally needed to generate accurate simulations [5,6]. Coarse topographical and geographical data affect the overland routing process simulation by inaccurately identifying land surface features [7].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
