River Valley Boundaries and transects Generated for Select Large Rivers of the Upper Midwest, United States
Dates
Publication Date
2019-12-12
Time Period
2018-09-25
Citation
Rohweder, J., 2019, River Valley Boundaries and Transects Generated for Select Large Rivers of the Upper Midwest, United States: U.S. Geological Survey data release, https://doi.org/10.5066/P9HFYOLO.
Summary
River valley boundary extents were generated for select large river floodplains of the Upper Midwest, United States. These polygons were delineated using a method that incorporated interpolating a water surface elevation that completely over-topped water-control structures within the valley such as levees, flood walls, and roadways. The intersection of this derived water surface and land elevation at the outermost edge of the floodplain was used to delineate the approximate extent of the river valley boundary. We used best professional judgment to approximate this water surface elevation. River transects were generated at 1-mile increments across select large river floodplains of the Upper Midwest, United States. These transects [...]
Summary
River valley boundary extents were generated for select large river floodplains of the Upper Midwest, United States. These polygons were delineated using a method that incorporated interpolating a water surface elevation that completely over-topped water-control structures within the valley such as levees, flood walls, and roadways. The intersection of this derived water surface and land elevation at the outermost edge of the floodplain was used to delineate the approximate extent of the river valley boundary. We used best professional judgment to approximate this water surface elevation. River transects were generated at 1-mile increments across select large river floodplains of the Upper Midwest, United States. These transects were created perpendicular to the river valley bottom centerline and were clipped by the floodplain boundary also generated. Transects that extended up into the valleys of connecting tributaries were not included because of spatial bias toward very large values. Inclusive features within the derived valley bottom outline such as raised plateaus were removed. The total length of these extended transects was then calculated. Five separate variables were developed to assess geomorphic connectivity potential using the transects: channel sinuosity, average floodplain width, standard deviation of floodplain width, average percent of length of transects behind (landward of) levees, coefficient of variation of transect length behind levees.
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Related External Resources
Type: Related Primary Publication
Jacobson, R.B., Rohweder, J.J., and De Jager, N.R., 2019, A hydrogeomorphic classification of connectivity of large rivers of the Upper Midwest, United States: Scientific Investigations Report, https://doi.org/10.3133/sir20195132.
River valley boundary extents were generated to allow researchers the ability to quantify multiple geomorphic metrics important in classifying large river floodplains.