Developing Regional Curves for Estimating Bankfull Geometry for Streams in Georgia
Stream channels often are disturbed by human activities such as construction or agriculture. In recent years, scientists and engineers have begun to apply the principles of natural channel design to the construction and restoration of stream channels. Natural channel design, or “stream restoration” involves rebuilding a channel with the appropriate dimensions, slope, and plan view pattern so that it can pass the water and sediment loads supplied to it without aggrading or degrading. Stream channels designed to approximate natural stable conditions are more likely to remain in equilibrium over time and therefore reduce erosion and sedimentation and provide suitable aquatic habitat. An important component of this design and restoration is the development of regional curves, or mathematical relations, that estimate the bankfull geometry and discharge for a stream location.
Problem/Objective/Scope:
Past studies focused on two of the six Georgia ecological regions (Piedmont and Southern Coastal Plain), this study will develop regional curves relating bankfull area, depth, and width to drainage area for each of the US Environmental Protection Agency (EPA) Level III ecoregions in Georgia using direct measurements of bankfull geometry at up to 150 selected stream locations in Georgia and the nearby area surrounding Georgia.
Approach:
The regional curves relating bankfull discharge with drainage area will be developed by employing the methods described in Rosgen (1996). A general overview of the approach is as follows:
- Bankfull indicators will be surveyed at up to 25 stream locations in each Level III ecoregion in Georgia. For the Southwestern Appalachians Level III ecoregion, it may be difficult to find 15 locations in Georgia due to the limited size of this ecoregion in Georgia. Locations in the nearby surrounding States will be used for this ecoregion if needed. The sites selected will have less than 20 percent of the streamflow regulated, less than 25 percent of the land use in the watershed upstream from the station developed, and a drainage area between 1 and 300 square miles.
- Multilinear Regression analyses with be performed using the methods in Farmer and others (2019) to develop regional curves relating bankfull area, depth, and width to drainage area for each Level III ecoregion.
References:
Bieger, Katrin; Rathjens, Hendrik; Allen, Peter M.; and Arnold, Jeffrey G., 2015, Development and Evaluation of Bankfull Hydraulic Geometry Relationships for the Physiographic Regions of the United States, Publications from USDA-ARS / UNL Faculty, 17p.
Dalrymple, T., and Benson, M.A., 1967, Measurement of peak discharges by the slope-area method: U.S. Geological Survey Techniques of Water-Resources Investigations, book 3, chap. A2, 12 p.
Dunne, Thomas, and Leopold, L.B., 1978, Water in environmental planning: San Francisco, W.H. Freeman, 818 p.
Farmer, W.H., Kiang, J.E., Feaster, T.D., and Eng, K., 2019, Regionalization of surface-water statistics using multiple linear regression (ver. 1.1, February 2021): U.S. Geological Survey Techniques and Methods, book 4, chap. A12, 40 p., https://doi.org/10.3133/tm4A12.
Rosgen, D.L,, 1996, Applied River Morphology: Minneapolis, Minn., Printed Media Companies.
Stream channels often are disturbed by human activities such as construction or agriculture. In recent years, scientists and engineers have begun to apply the principles of natural channel design to the construction and restoration of stream channels. Natural channel design, or “stream restoration” involves rebuilding a channel with the appropriate dimensions, slope, and plan view pattern so that it can pass the water and sediment loads supplied to it without aggrading or degrading. Stream channels designed to approximate natural stable conditions are more likely to remain in equilibrium over time and therefore reduce erosion and sedimentation and provide suitable aquatic habitat. An important component of this design and restoration is the development of regional curves, or mathematical relations, that estimate the bankfull geometry and discharge for a stream location.
Problem/Objective/Scope:
Past studies focused on two of the six Georgia ecological regions (Piedmont and Southern Coastal Plain), this study will develop regional curves relating bankfull area, depth, and width to drainage area for each of the US Environmental Protection Agency (EPA) Level III ecoregions in Georgia using direct measurements of bankfull geometry at up to 150 selected stream locations in Georgia and the nearby area surrounding Georgia.
Approach:
The regional curves relating bankfull discharge with drainage area will be developed by employing the methods described in Rosgen (1996). A general overview of the approach is as follows:
- Bankfull indicators will be surveyed at up to 25 stream locations in each Level III ecoregion in Georgia. For the Southwestern Appalachians Level III ecoregion, it may be difficult to find 15 locations in Georgia due to the limited size of this ecoregion in Georgia. Locations in the nearby surrounding States will be used for this ecoregion if needed. The sites selected will have less than 20 percent of the streamflow regulated, less than 25 percent of the land use in the watershed upstream from the station developed, and a drainage area between 1 and 300 square miles.
- Multilinear Regression analyses with be performed using the methods in Farmer and others (2019) to develop regional curves relating bankfull area, depth, and width to drainage area for each Level III ecoregion.
References:
Bieger, Katrin; Rathjens, Hendrik; Allen, Peter M.; and Arnold, Jeffrey G., 2015, Development and Evaluation of Bankfull Hydraulic Geometry Relationships for the Physiographic Regions of the United States, Publications from USDA-ARS / UNL Faculty, 17p.
Dalrymple, T., and Benson, M.A., 1967, Measurement of peak discharges by the slope-area method: U.S. Geological Survey Techniques of Water-Resources Investigations, book 3, chap. A2, 12 p.
Dunne, Thomas, and Leopold, L.B., 1978, Water in environmental planning: San Francisco, W.H. Freeman, 818 p.
Farmer, W.H., Kiang, J.E., Feaster, T.D., and Eng, K., 2019, Regionalization of surface-water statistics using multiple linear regression (ver. 1.1, February 2021): U.S. Geological Survey Techniques and Methods, book 4, chap. A12, 40 p., https://doi.org/10.3133/tm4A12.
Rosgen, D.L,, 1996, Applied River Morphology: Minneapolis, Minn., Printed Media Companies.