Conventional methods for addressing beach erosion are ineffective because they often fail to address the major causes, which are sand dune destruction, longshore drift disruption, and saltwater intrusion, points out Amine Dahmani, senior project manager at SESI Consulting Engineers. “An overlooked and underestimated contributor to coastal erosion is the change in the characteristics of sand introduced during beach nourishment,” he says. “Imported beach sand is non-cohesive and is easily eroded and suspended in water, even under moderate wave action.” The imported sand can have other detrimental effects, such as impoverishing biotic diversity, says Dahmani, adding that the natural chemical and physical properties of sand are critical to the health of a beach because they provide a means of interacting with and retaining water. One potential solution to enhancing the physical and biological properties of sand is the use of natural biopolymers that can improve sand cohesion and water retention. Dahmani has been developing protein polysaccharide biopolymer (PPB) formulations based on site-specific characteristics of sand and water chemistry. One of the PPB formulations, SandFirst (SF), was tested successfully in a beach stabilization application in Mexico’s Yucatan peninsula on a previously renourished beach. Beach profiles and sand accretion and erosion were monitored for a SF-treated beach section (85 meters) and compared to two similar untreated beach sections (controls) located on both sides of the treated beach. Beach profiles were measured monthly to assess the PPB effectiveness in controlling beach erosion, with results indicating beach width increased in the SF-treated section while control sections displayed continued erosion. That and other findings suggested PPBs may be a promising eco-friendly method for enhancing renourished beach retention, according to SESI officials.
What He Does Day to Day
Dahmani continues to develop the beach stabilization technology through laboratory and field testing. He spends significant time presenting the technology at conferences and meeting with stakeholders. He also works on developing soil, sediment, and groundwater remediation solutions for SESI’s clients nationally. The company provides environmental, soils and foundations, water resources, geostructural, and land planning services.
What Led Him to This Line of Work
Dahmani earned a Ph.D. in petroleum engineering from Louisiana State University. He worked in the oil industry for four years before joining the University of Connecticut to work on environmental remediation. He later worked for an environmental testing laboratory and more recently in engineering consulting. In addition to his work as senior project manager for SESI Consulting Engineers, he serves as an associate professor in residence for the civil and environmental engineering department at the University of Connecticut.
What He Likes Best About the Work
“I am fascinated by developing innovative approaches to beach erosion, because there are limited options available and society has failed to deal with the problem in a holistic way,” says Dahmani. He spends a lot of time educating people on beach erosion and the impact of the current solutions that are being implemented. “For a problem impacting a large percentage of coastal communities, there is a dearth of knowledgeable scientists, regulators, and local government officials who can explain to the public what is at stake if we fail to devise sustainable methods for mitigating beach erosion,” he says. He adds that he feels a sense of responsibility to do his part to try to educate people on the topic and advance the science of beach erosion control to achieve coastal resilience for future generations.
His Greatest Challenge
When problem-solving outside the box, there is always a concern about acceptance, says Dahmani. “The beach erosion control industry has focused on replenishing beaches with sand to repair beach erosion,” he adds. “However, they have not looked at ways to retain the sand. As a result, we are in a bind because sand sources often become depleted, and when there is a lack of sand to replenish beaches, this approach becomes cost-prohibitive. We need to take a serious and overdue look at ways to retain sand. While bringing innovative solutions to the problem still requires significant efforts to educate the public and various stakeholders and to overcome biases toward more familiar beach erosion control measures, it is necessary to do before it is too late to save beaches, animals, and property.”
