Abstract
This paper examines the impact of raster cell size on hydrographic feature extraction and hydrological modeling using LiDAR (Light Detection and Ranging)-derived Digital Elevation Model (DEM) data. LiDAR datasets for three experimental watersheds were converted to DEMs at 1 m, 5 m, 10 m, 30 m and 60 m cell sizes. Watershed boundaries and stream network centerlines were delineated from each DEM using a geographic information system (GIS) and were compared to reference vector data. Hydrological simulations were conducted using the DEMs with different resolutions and the outputs were compared. Higher resolution DEMs consistently resulted in less difference between DEM-delineated features and reference data. However, when these delineated features at each cell resolution were used to define hydrologic model physical constraints, only minor differences between streamflow simulations resulted for daily and monthly simulations aggregated at an annual average. Further study is needed to predict streamflow at sub daily time steps using higher resolution DEM's. These findings indicate that while higher resolution DEM grids may result in more accurate representation of terrain characteristics, such variations in watershed shape, slope, length and sinuosity at each cell size do not necessarily improve watershed scale simulation modeling. Hence the additional expense of generating high resolution DEM's for the express purpose of watershed modeling at daily or longer time steps may not be warranted.
Original language | English |
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Pages | 2338-2345 |
Number of pages | 8 |
State | Published - 2014 |
Externally published | Yes |
Event | 7th International Congress on Environmental Modelling and Software, iEMSs 2014 - San Diego, United States Duration: Jun 15 2014 → Jun 19 2014 |
Conference
Conference | 7th International Congress on Environmental Modelling and Software, iEMSs 2014 |
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Country/Territory | United States |
City | San Diego |
Period | 06/15/14 → 06/19/14 |
Keywords
- Digital elevation model
- Hydrographic feature extraction
- Hydrologic modeling
- LiDAR
- Stream networks
- Terrain analysis