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Evaluating the BANCS Streambank Erosion Framework on the Northern Gulf of Mexico Coastal Plain
Author(s) -
McMillan Mitchell,
Liebens Johan,
Metcalf Christopher
Publication year - 2017
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 - 10.1111/1752-1688.12572
Subject(s) - hydrology (agriculture) , bank erosion , erosion , beach morphodynamics , sediment , coastal plain , geology , context (archaeology) , environmental science , geomorphology , sediment transport , geotechnical engineering , paleontology
The Bank Assessment of Nonpoint source Consequences of Sediment ( BANCS ) framework allows river scientists to predict annual sediment yield from eroding streambanks within a hydrophysiographic region. BANCS involves field data collection and the calibration of an empirical model incorporating a bank erodibility hazard index ( BEHI ) and near‐bank shear stress ( NBS ) estimate. Here we evaluate the applicability of BANCS to the northern Gulf of Mexico coastal plain, a region that has not been previously studied in this context. Erosion rates averaged over two years expressed the highest variability of any existing BANCS study. As a result, four standard BANCS models did not yield statistically significant correlations to measured erosion rates. Modifications to two widely used NBS estimates improved their correlations ( r 2 = 0.31 and r 2 = 0.33), but further grouping of the data by BEHI weakened these correlations. The high variability in measured erosion rates is partly due to the regional hydrologic and climatic characteristics of the Gulf coastal plains, which include large, infrequent precipitation events. Other sources of variability include variations in bank vegetation and the complex hydro‐ and morphodynamics of meandering, sand bed channels. We discuss directions for future research in developing a streambank erosion model for this and similar regions.