State Highway Shoreline Protection Program
Drs. Oceana Francis, Horst Brandes and David Ma obtained a three year (2017-2019) project from the Hawaii Department of Transportation (about $700,000) to identify threats to the integrity of State roads posed by rising sea levels and coastal erosion. The research is aimed at identifying and ranking road sections according to their vulnerability to rising water levels from the effects of climate change. A preliminary assessment has already been completed for Oahu, Maui, Kauai and Hawaii, yielding recommendations on the most critical sections that require immediate remediation and proposed mitigation solutions.
More detailed studies are now underway combining scientifically rigorous sea level predictions that take into account potential storm surges and tidal variations, with accurate and detailed topographic road and coastal elevation surveys. A methodology and specific criteria are being developed to identify and prioritize sites for medium and long-term mitigation efforts. The criteria will consider coastal hazards and processes, climate change and sea level rise, coastal erosion rates, risk, connectivity, affected population, current and project land use, socio-economic impacts, benefit-cost, lifecycle, environment, cost of mitigation, risk assessment and other factors deemed important.
The benefit of this study is that it will provide specific direction to the HDOT in its effort to optimize the use of limited funds for road infrastructure improvement and maintenance.
Bio-mediated and bio-inspired geotechnics in coastal applications
Dr. Ningjun Jiang is using intramural funds to investigate bio-mediated and bio-inspired geotechnics in coastal applications.
Resilient and natural-based approaches are being sought to mitigate various coastal hazards such as flooding, erosion and saltwater intrusion. Bio-cementation, as an effective method for soil improvement, has the potential to stabilize erodible and permeable coastal sands. Bio-cementation can be triggered via various naturally microbial processes such as ureolysis, denitrification, and sulfate reduction. Attempts are made to stimulate ureolytic, denitrifying, and sulfate-reduction bacteria in coastal sands on the Hawaiian Islands. The favorable conditions for each microbial process are identified in terms of enrichment media and oxygen availability. Engineering solutions are then designed based on these bio-cementation processes to address specific coastal hazards.