USGS AHG Parameters and Supplementary Data

Published: 19-06-2020| Version 1 | DOI: 10.17632/chvbsgvv27.1
Shahab Afshari


Summary: The ArcGIS Online web map presents information on the geospatial variations of Hydraulic Geometry parameters, morphological/geophysical variables, Manning's n coef., and suspended sediment information at U.S. Geological Survey's river monitoring stations across CONUS. Full Description: Simplified hydraulic geometry relationships representing the average conditions over longer reaches could reduce the need for detailed field surveys and minimize the computational burden while studying river channel flow dynamics. Natural streams are characterized by changes in cross-section geometry and geophysical properties (e.g., bed-roughness, channel slope, channel planform, sediment load, etc.) along their reaches. Variations in the shape of the channel bed geometry are affected by several interacting features including the effect of different flow regimes, channel slope, sediment load, etc. Simplifying the river bed geometries will reduce the burden of assembling the required data and computational burden. “At-A-Station” Hydraulic Geometry (or AHG) relations are power-law functions that relate key hydraulic variables (i.e., velocity, depth, width, and flow area) to discharge at a river monitoring station (Dingman 2007; Dingman and Afshari 2018). The AHG relations have been introduced and discussed among researchers, engineers, and geomorphologists since the '50s based upon a limited number of observations made over a few flow monitoring stations across the United States. Afshari et. al., 2017 introduced a data filtering procedure that was trained and tested over both synthetic and realistic data followed by being applied over ~4000 U.S. Geological Survey’s river monitoring stations to compute AHG parameters based upon robust hydraulic vs. discharge measures. Estimated AHG parameters are combined with basic statistics (mean, minimum, maximum, and standard deviation) of key morphological and geophysical features at all USGS river monitoring sites, e.g. stream (Stahler) order, channel pattern (channel sinuosity), channel bed-slope, and channel lateral [or overbank] slope. The fundamental hydraulics, geographical, and geophysical data sources (websites) applied for making the "USGS Table AHG Parameters And Supplementary Data" table are - USGS National Water Information System (USGS-NWIS) - USGS Staged Product Directory (The National Map) - National Hydrography Dataset Plus V2 (Horizon System Corporation) In doing so, potential interrelation among independent and dependent variables will be highlighted. Accordingly, given some assumptions, it is verified how well channel morphology and hydraulic components are intertwined and combined with AHG parameters and how categorizing river monitoring stations according to these characteristics will be practical and useful for further studies.