We are wrapping up a one-year collaborative project between USA, the Mississippi Department of Transportation (MDOT), and the US Department of Transportation Federal Highway Administration (USDOT FHWA).  This was one of five pilot projects funded by USDOT FHWA to evaluate the use of green infrastructure for improving the resilience of coastal transportation systems. The pilot projects are an initial step in a more comprehensive effort by USDOT FHWA to develop an implementation guide for nature-based solutions that improve resilience. More information about that project is found at the following link {click here}.

Our pilot project with MDOT was focused on improving the resilience of a coastal bridge in Mississippi to hurricane hazards and future sea level rise. More specifically, our green infrastructure approach was designed to address the vulnerability of bridge approaches and low-elevation bridge spans. The causes of damage to the bridge during Katrina were determined through the use of hydrodynamic models. A hindcast simulation of Katrina was performed using the coupled ADCIRC+SWAN models. Those results were extracted and used to force a high-resolution, two-dimensional simulation using the XBeach model. An animation of some of those results is provided below.

To that end, a pair of vegetated berms were designed in order to mitigate storm damage now and in the future during extreme events.

An overview of the entire pilot project is available in a recorded webinar at the following link {click here for webinar}. Ours is the second presentation in the webinar recording (at about the 25-minute mark). Webinar recordings for all five pilot projects, as well as other presentations in an ongoing USDOT FHWA resilience series, can be found at the following link {click here for all webinars}. A brief animation of our presentation slides is available by clicking on the title slide image in this post.

Katrina Hindcast using XBeach, forced with ADCIRC+SWAN output…

Hindcast of Katrina using XBeach: Terrain elevation contour colors correspond to the lower blue-green-brown-white color scale. Selected bathymetric contours are shown as dashed white lines on the surface. The animated water surface is contoured by significant wave height using the blue-white-red scale. Vectors represent the depth-averaged flow magnitude and direction, but only at every 1/10th grid cell for clarity.