Contact

Bret M. Webb, Ph.D., P.E., D.CE
Professor
University of South Alabama
150 Jaguar Drive, SH3142
Mobile, AL 36688 USA
Phone: (251) 460-6174
Fax: (251) 461-1400
Email: bwebb@southalabama.edu

Research Positions

Currently seeking an MSCE student to perform research on groundwater impacts to coastal lagoons. A research assistantship is available. Contact me for more details.

Current Research Assistants

SE Students
Garland Pennison

 

MSCE Students
Patrick Hautau
Marshall Hayden
Kate Haynes
Jackie Wittmann

 

Undergraduate Students
Derek Kelly

Former Students

MSCE Students
Bryan Groza (2016)
Kari Servold (2015)
Chris Marr (2013)
Richard Allen (2013)
Miyuki Matthews (2012)

 

Post Docs
Jon Risinger
Jungwoo Lee

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research

Title slide image for ASBPA 2017 presentation

I recently presented the results of a year-long research project on synthesizing the capacity of natural and nature-based features (NNBF) to reduce coastal storm hazards. The presentation was given in the Living Shorelines session at ASPA 2017 in Fort Lauderdale, Florida in October. The project, and presentation, were a collaboration between researchers at USA, the Dauphin Island Sea Lab, Northeastern University, the City College of New York, and the US Army Corps of Engineers Engineer Research and Development Center who funded the project.

 

More than 200 published research papers were identified, evaluated, and synthesized in this work. The synthesis focuses on the ability of marshes, mangroves, maritime forests, seagrasses, reefs, beaches, and dunes to attenuate waves, storm surge, flooding, and erosion. With very few exceptions, the literature does not contain unified methods for analyzing and describing these capabilities, and the range of values describing their performance is broad. Regardless of the uncertainty in published values, there is literature that supports the capacity of each of the NNBF considered to provide some measurable reduction of coastal storm hazards. A logical next step is to perform a detailed meta-analysis on values reported in these publications in order to determine average performance values and characterizations of their uncertainty.

 

A short animation of the presentation can be viewed by clicking on the title slide shown here. Please contact me for a full copy of the presentation.

 

boatwakestudysite-westfowlriverWe recently deployed a GoPro Hero 3 camera and two RBR D|wave gages to study boat wakes and boat traffic at a site on West Fowl River (AL) over the Labor Day weekend. The GoPro is set to capture photos every 10 s using the time lapse mode. It is wired to an external battery using the LongShot battery elimination system. The wave gages were configured independently such that one is sampling continuously and the other is processing bursts of waves every five minutes. These two sampling schemes will allow us to study the boat wake signatures in great detail (continuous sampling) and also in summary form (wave bursts). The camera system should allow us to match boat wake signatures with the vessels that generated them. While not perfect, we may also be able to estimate boat size and speed from the time lapse photos.

Here is a time lapse video (~30 seconds) of the installation at our study site…

 

 

Pres-cover-pageThe latest study out of our ACES center (Applied Coastal Engineering & Science) is now available. The study, entitled “Lake Forest Mapping: Analysis of Shoaling and Pool Volumes,” was recently completed for the Lake Forest Property Owner’s Association and the City of Daphne with contracting support provided by the Mobile Bay National Estuary Program. The goals of the study were to determine how much sediment has accumulated in the Lake Forest lake (reservoir) since the time of dam construction in 1973/1974, where the largest accumulations of sediment have occurred, and what the remaining normal pool volume is within the lake.

We collected over 12,000 new elevation measurements within and around the lake to map the sediment elevations and also analyzed eight (8) shallow sediment push cores from the lake bed. The results of the study show that over 300,000 cubic yards of medium to coarse grained sediments have accumulated, or shoaled, within the present-day lake shoreline since 1973/1974. Approximately 80% of the lake has shoaled by some measurable amount since the time of dam construction, with some areas accumulating over ten (10) feet of sediment! As a result, the pool volume of the lake has decreased by about 60% due to the accumulation of sediments. The remaining volume could perhaps accommodate another 90 years of sediment input at the current reported rate of 7800 tons per year (as per Cook & Moss, 2008[1]), but the margin for error is quite large.

I presented these study results at a recent Mobile Bay National Estuary Program’s Project Implementation Committee Meeting. A copy of that presentation [2] can be downloaded {here}.  A copy of the final study report [3] can be downloaded {here}.  Please include proper attribution and/or citation [2,3] when reusing these data, results, graphics, and/or figures.

[1] Cook, M., and Moss, N. 2008. Analysis of Water Quality, Sediment Loading Rates, Biological Resources, and Impacts of Land-Use Change on the D’Olive and Tiawasee Creek Watersheds, Baldwin County, Alabama, 2008. Geological Survey of Alabama, Open File Report 08-11: 92 pp.

[2] Webb, B.M. 2016. Lake Forest Mapping: Analysis of Shoaling and Pool Volumes. Mobile Bay National Estuary Program Project Implementation Committee Meeting. August 18, 2016. Presentation.

[3] Webb, B.M. 2016. Lake Forest Mapping: Analysis of Shoaling and Pool Volumes. University of South Alabama, Center for Applied Coastal Engineering and Science, Technical Report No. 16-002F. 41 pp.

 

Fig07 for web site

Our manuscript entitled “Spatial Variability of Hydrodynamic Timescales in a Broad and Shallow Estuary: Mobile Bay, Alabama” has been published by the Journal of Coastal Research. The manuscript is currently available online as a pre-print. The final version with color will be available in the coming months. Please {click on this link} for access to the manuscript.

The results presented in this new manuscript by Webb and Marr (2016) were initially developed as part of Chris Marr’s thesis research back in 2013. This new manuscript presents a much more narrow focus of his work and some new analyses as well. For more information about this work please review the {thesis} by Marr and/or this previous {blog post}.

 

 

 

I am searching for an undergraduate student to assist with coastal engineering research. I currently have one opening for a paid undergraduate research assistant position in spring 2016. Continuation of the research position will be contingent upon the receipt of additional funding.

 

The research assistant will be permitted to work up to a maximum of 20 hours per week for a maximum wage of $9/hour. Initially, the assistant will work for 10 hours per week at a wage of $8.50/hour. The duties of the research assistant will be:
 

1) to conduct and complete original coastal engineering research as assigned by the supervisor
2) to assist with laboratory experiments
3) to assist with field experiments

 

Those interested in this research position must submit a printed resume (no page limits) and statement of interest (max 1 page) to Dr. Webb by December 1, 2015. Applications by email will not be considered. The statement of interest must address, at a minimum, the following items:

 

A) your interest in coastal engineering
B) your current academic standing (GPA)
C) your schedule for spring 2016
D) any other on-campus and/or off-campus employment*

 

*Note: you must disclose any and all existing or planned employment for spring 2016 (excluding this position). Your application will not be considered if item D is not specifically addressed in the statement.