Slope Area Index (SAI) of North Carolina
Slope-Area Index (SAI) is used to predict erosion along a stream channel. It is a function of channel slope, and drainage area upstream raised to the exponent used in equations for flood frequency of 2-percent exceedance floods. The guidelines for use of the coefficient from 2-percent exceedance came from meetings with cooperators describing bankfull discharge as a 2-percent exceedance.
The Slope-Area Index, as defined by Cartwright and Diehl, 2017, is calculated as:
SAI = S * A^b (1)
where
SAI is the slope-area index,
S is the channel slope,
A is the drainage area (the number of cells draining into the target cell), and b is a user-specified exponent.
The flood frequency report for NC (Weaver and others, 2009) defines the regional regression equations for exceedance flows for rural basins in the Southeast. The 2-percent chance exceedance flow raises the Drainage Area uses a 0.60 coefficient for all the physiographic provinces other than Small Urban basins in the Piedmont.
The Urban equations drainage area coefficients for 2-percent exceedance flow (Feaster and others, 2014) were used for Piedmont (HLR2) urban basins. Urban basins were defined as catchments which were greater than 10% developed (urban).
For piedmont (HLR2, small urban le 3 dasqmi and pcturb gt 10%) SAI = slope*da^0.8
For piedmont (HLR2, small urban dasqmi gt 3 and le 436 and pcturb ge 10%) SAI = slope * da^.5
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Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[ "010:12" ] |
| contactPoint |
{ "fn": "Silvia Terziotti", "@type": "vcard:Contact", "hasEmail": "mailto:seterzio@usgs.gov" } |
| description | Slope-Area Index (SAI) is used to predict erosion along a stream channel. It is a function of channel slope, and drainage area upstream raised to the exponent used in equations for flood frequency of 2-percent exceedance floods. The guidelines for use of the coefficient from 2-percent exceedance came from meetings with cooperators describing bankfull discharge as a 2-percent exceedance. The Slope-Area Index, as defined by Cartwright and Diehl, 2017, is calculated as: SAI = S * A^b (1) where SAI is the slope-area index, S is the channel slope, A is the drainage area (the number of cells draining into the target cell), and b is a user-specified exponent. The flood frequency report for NC (Weaver and others, 2009) defines the regional regression equations for exceedance flows for rural basins in the Southeast. The 2-percent chance exceedance flow raises the Drainage Area uses a 0.60 coefficient for all the physiographic provinces other than Small Urban basins in the Piedmont. The Urban equations drainage area coefficients for 2-percent exceedance flow (Feaster and others, 2014) were used for Piedmont (HLR2) urban basins. Urban basins were defined as catchments which were greater than 10% developed (urban). For piedmont (HLR2, small urban le 3 dasqmi and pcturb gt 10%) SAI = slope*da^0.8 For piedmont (HLR2, small urban dasqmi gt 3 and le 436 and pcturb ge 10%) SAI = slope * da^.5 |
| distribution |
[ { "@type": "dcat:Distribution", "title": "Digital Data", "format": "XML", "accessURL": "https://doi.org/10.5066/P9PRAVAQ", "mediaType": "application/http", "description": "Landing page for access to the data" }, { "@type": "dcat:Distribution", "title": "Original Metadata", "format": "XML", "mediaType": "text/xml", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.5b72ee9fe4b0f5d5787c5723.xml" } ] |
| identifier | http://datainventory.doi.gov/id/dataset/USGS_5b72ee9fe4b0f5d5787c5723 |
| keyword |
[ "USGS:5b72ee9fe4b0f5d5787c5723", "drainage area", "elevation", "geomorphology", "sediment", "slope" ] |
| modified | 2024-02-08T00:00:00Z |
| publisher |
{ "name": "U.S. Geological Survey", "@type": "org:Organization" } |
| spatial | -84.6982, 33.4746, -75.3018, 37.5216 |
| theme |
[ "geospatial" ] |
| title | Slope Area Index (SAI) of North Carolina |
