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Development and Comparison of Multiple Regression Models to Predict Bankfull Channel Dimensions for Use in Hydrologic Models
Author(s) -
Bieger Katrin,
Rathjens Hendrik,
Arnold Jeffrey G.,
Chaubey Indrajeet,
Allen Peter M.
Publication year - 2016
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/1752-1688.12460
Subject(s) - regression analysis , regression , channel (broadcasting) , hydrology (agriculture) , variables , statistics , division (mathematics) , linear regression , streamflow , hydrological modelling , mathematics , environmental science , drainage basin , computer science , geology , geography , climatology , geotechnical engineering , computer network , arithmetic , cartography
Channel dimensions are important input variables for many hydrologic models. As measurements of channel geometry are not available in most watersheds, they are often predicted using bankfull hydraulic geometry relationships. This study aims at improving existing equations that relate bankfull width, depth, and cross‐sectional area to drainage area ( DA ) without limiting their use to well‐gauged watersheds. We included seven additional variables in the equations that can be derived from data that are generally required by hydrologic models anyway and conducted several multiple regression analyses to identify the ideal combination of additional variables for nationwide and regional models for each Physiographic Division of the United States (U.S.). Results indicate that including the additional variables in the regression equations generally improves predictions considerably. The selection of relevant variables varies by Physiographic Division, but average annual precipitation ( PCP ) and temperature ( TMP ) were generally found to improve the models the most. Therefore, we recommend using regression equations with three independent variables ( DA , PCP , and TMP ) to predict bankfull channel dimensions for hydrologic models. Furthermore, we recommend using the regional equations for watersheds within regions from which data were used for model development, whereas in all other parts of the U.S. and the rest of the world, the nationwide equations should be given preference.