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Abstract Delineating accurate flowlines using digital elevation models is a critical step for overland flow modeling. However, extracting surface flowlines from high‐resolution digital elevation models (HRDEMs) can be biased, partly due to the absence of information on the locations of anthropogenic drainage structures (ADS) such as bridges and culverts. Without the ADS, the roads may act as “digital dams” that prevent accurate delineation of flowlines. However, it is unclear what variables for terrain‐based hydrologic modeling can be used to mitigate the effect of “digital dams.” This study assessed the impacts of ADS locations, spatial resolution, depression processing methods, and flow direction algorithms on hydrologic connectivity in an agrarian landscape of Nebraska. The assessment was conducted based on the offset distances between modeled drainage crossings and actual ADS on the road. Results suggested that: (a) stream burning in combination with the D8 or D‐Infinity flow direction algorithm is the best option for modeling surface flowlines from HRDEMs in an agrarian landscape; (b) increasing the HRDEM resolution was found significant for facilitating accurate drainage crossing near ADS locations; and (c) D8 and D‐Infinity flow direction algorithms resulted in similar patterns of drainage crossing at ADS locations. This research is expected to result in improved parameter settings for HRDEMs‐based hydrologic modeling.
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A national topographic dataset for hydrological modeling over the contiguous United States
Abstract. Topography is a fundamental input to hydrologic models criticalfor generating realistic streamflow networks as well as infiltration andgroundwater flow. Although there exist several national topographic datasetsfor the United States, they may not be compatible with gridded models thatrequire hydrologically consistent digital elevation models (DEMs). Here, wepresent a national topographic dataset developed to support griddedhydrologic simulations at 1 km and 250 m spatial resolution over the contiguousUnited States. The workflow is described step by step in two parts: (a) DEMprocessing using a Priority Flood algorithm to ensure hydrologicallyconsistent drainage networks and (b) slope calculation and smoothing toimprove drainage performance. The accuracy of the derived stream network isevaluated by comparing the derived drainage area to drainage areas reportedby the national stream gage network. The slope smoothing steps are evaluatedusing the runoff simulations with an integrated hydrologic model. Our DEMproduct started from the National Water Model DEM to ensure our finaldatasets will be as consistent as possible with this existing nationalframework. Our analysis shows that the additional processing we provideimproves the consistency of simulated drainage areas and the runoffsimulations that simulate gridded overland flow (as opposed to a networkrouting scheme). The workflow uses an open-source R package, and all outputdatasets and processing scripts are available and fully documented. All ofthe output datasets and scripts for processing are published through CyVerseat 250 m and 1 km resolution. The DOI link for the dataset is https://doi.org/10.25739/e1ps-qy48 (Zhang and Condon, 2020).
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- Award ID(s):
- 1835794
- PAR ID:
- 10297799
- Date Published:
- Journal Name:
- Earth System Science Data
- Volume:
- 13
- Issue:
- 7
- ISSN:
- 1866-3516
- Page Range / eLocation ID:
- 3263 to 3279
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/essd-13-3263-2021
