Empirical Assessment of Backward Erosion Piping via Blanket Thickness, Lower Mississippi Valley

Backward erosion piping (BEP) is a form of internal erosion and common failure mode along levees. Despite over a century of study, predicting where BEP will initiate is still a considerable challenge. This study proposes a new model for predicting BEP initiation focused on the widest range of applicability. A logit model is trained using data from 15 sites along the Lower Mississippi Valley. The included parameters are independent of geography or geological regime and exhibit recorded or suspected correlations to BEP. Three significant factors (95% confidence interval) are retained for the final model: cumulative clay thickness within the blanket (odds ratio (OR) 0.520), critical gradient (OR 0.001) and exit gradient (OR 63.15). Receiver operating characteristics analysis indicates an area under the curve of 0.823. The model demonstrates 71% classification accuracy, a dramatic 10% increase over previous logit model attempts. Model results are most applicable within 150 m of the levee toe to predict new incidents of BEP initiation. The final model is a useful tool for BEP assessment and mitigation efforts.

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Automated characterization of ridge-swale patterns along the Mississippi River

10.21079/11681/40439 ◽

2021 ◽

Author(s):

Alicia Downard ◽

Stephen Semmens ◽

Bryant Robbins

Keyword(s):

Mississippi River ◽

Machine Learning Algorithms ◽

Training Data ◽

Mississippi Valley ◽

Lower Mississippi Valley ◽

Linear Feature ◽

Topographic Features ◽

Backward Erosion Piping ◽

The Individual

The orientation of constructed levee embankments relative to alluvial swales is a useful measure for identifying regions susceptible to backward erosion piping (BEP). This research was conducted to create an automated, efficient process to classify patterns and orientations of swales within the Lower Mississippi Valley (LMV) to support levee risk assessments. Two machine learning algorithms are used to train the classification models: a convolutional neural network and a U-net. The resulting workflow can identify linear topographic features but is unable to reliably differentiate swales from other features, such as the levee structure and riverbanks. Further tuning of training data or manual identification of regions of interest could yield significantly better results. The workflow also provides an orientation to each linear feature to support subsequent analyses of position relative to levee alignments. While the individual models fall short of immediate applicability, the procedure provides a feasible, automated scheme to assist in swale classification and characterization within mature alluvial valley systems similar to LMV.

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American Indians in the Lower Mississippi Valley: Social and Economic Histories, par Daniel H. Usner, Jr.American Indians in the Lower Mississippi Valley: Social and Economic Histories, par Daniel H. Usner, Jr. Lincoln, Nebraska, University of Nebraska Press, 1998. xvi, 189 pp. $45.00 U.S. (cloth).

Canadian Journal of History ◽

10.3138/cjh.35.1.177 ◽

2000 ◽

Vol 35 (1) ◽

pp. 177-178

Author(s):

Nelson Ouellet

Keyword(s):

American Indians ◽

Mississippi Valley ◽

Lower Mississippi Valley

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Presumed Trade and Aberrant Pottery

Memoirs of the Society for American Archaeology ◽

10.1017/s0081130000004901 ◽

1949 ◽

Vol 5 ◽

pp. 130-145

Author(s):

Alex D. Krieger

Keyword(s):

Mississippi Valley ◽

Lower Mississippi Valley ◽

Great Range ◽

Source Areas ◽

Site Occupation ◽

Foreign Origin ◽

Pronounced Deviation

The pottery in the following sections is not considered to belong to the Alto Focus complex, but to occur with it at different points in the Davis site occupation by trade or other means. If the writer appears to vacillate over what is and what is not trade pottery here, it is due in part to the problem of separating what could have been produced at the site (as extreme variations of resident styles) from what probably was not (because of some distinctive attribute which would mark it as foreign). In certain cases of pronounced deviation, a foreign origin is obvious enough, particularly when the source areas are well known. But where the whole tradition is similar as in the clay-tempered pottery of the lower Mississippi Valley region, and a great range of decorative techniques was employed for long periods of time, the problem is not easy.

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