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Slope stability of streambanks at saturated riparian buffer sites
Author(s) -
Dickey Loulou C.,
McEachran Andrea R.,
Rutherford Cassandra J.,
Rehmann Chris R.,
Perez Michael A.,
Groh Tyler A.,
Isenhart Thomas M.
Publication year - 2021
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.1002/jeq2.20281
Subject(s) - environmental science , riparian zone , riparian buffer , tile drainage , nitrate , environmental engineering , water quality , hydrology (agriculture) , drainage , soil water , geotechnical engineering , soil science , geology , ecology , habitat , biology
Saturated riparian buffers (SRBs) reduce nitrate export from agricultural tile drainage by infusing drainage water into carbon‐rich riparian soils where denitrification and plant uptake occur. The water quality benefits from SRBs are well documented, but uncertainties about their effect on streambank stability have led to design standards that limit the maximum bank height and minimum buffer width, thus reducing the number of suitable candidate sites. In this study, the relationship between SRB design and streambank stability was examined through numerical slope stability modeling and validated using field sites. At the study sites, the addition of SRB flow increased the probability of failure by less than 3% for both simulated dry and rainfall scenarios. Furthermore, the simulations provide no evidence to support excluding potential sites based on bank height alone. Multivariate analysis of dimensionless parameters developed for SRB flow conditions was used to predict the factor of safety as a function of the SRB site and design conditions. The equation presented allows designers to assess the stability of a potential site where bank failure poses a heightened risk. The results of this study alleviate the need for extensive geotechnical evaluations at future SRB sites and could increase SRB implementation by expanding the range of eligible sites.