Adapting to Climate Change

Changing Climate and our Infrastructure: The Gulf Coast Phase 2 Case Studies on Transportation Infrastructure Impacts

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Abstract

The Gulf Coast study is an initiative from the U.S Department of Transportation’s Center for Climate Change and Environmental Forecasting to study the projected impacts of climate change on transportation infrastructure in the Gulf Coast region. The project is being managed by FHWA with support from the USGS. The first phase of the pilot study focused on general climate change impacts on the central Gulf Coast region. The Phase 2 portion of the study is focused on the greater Mobile, Alabama area with the purpose of providing detailed assessments of critical infrastructure from specific climate change threats. The Gulf Coast Phase 2 study is being led by ICF International with Parsons Brinckerhoff as the engineering lead providing the detailed infrastructure studies.

This presentation will provide an outline of the general engineering process and two specific case studies of facilities located in Mobile, Alabama. The general engineering process as developed by Parsons Brinckerhoff is a five step process that consists of: 1) evaluation of existing infrastructure under historical climate conditions; 2) evaluation of existing infrastructure under projected future climate conditions; 3) identification of performance deficiencies; 4) development of adaptations to improve asset performance into the future; and 5) an economic analysis to guide the decision making process. The first case study involves the analysis of climate change impacts on the culvert crossing of Airport Boulevard, a major six-lane arterial, over Montlimar Creek. This case study includes investigation of increasing trends in precipitation due to climate change. Downscaled climatologic data prepared by the USGS were utilized for various SRES emissions scenarios. The study included detailed hydrologic modeling utilizing a range of NOAA-developed temporal rainfall distributions, HY-8 hydraulic modeling, and a Monte Carlo based benefit/cost simulation that considered damage costs and costs avoided (benefits) of the culvert system from current day up to the year 2090. Multiple adaptation schemes were considered for the culvert including expansion, re-construction as a bridge, and re-construction of the roadway. The second study focuses on I-10 in Mobile, a 10-lane portion of the freeway located near an estuary connected to Mobile Bay. This study presents a case that included detailed investigations into the coastal storm surge induced overtopping of the interstate and surrounding topography. The case study utilized Advanced Circulation (ADCIRC) modeling results developed for the Gulf Coast project which analyzed Hurricanes Georges and Katrina. Modified and intensified versions of Katrina were investigated to determine the impacts of possible future hurricane scenarios on the Interstate. Time-step analyses of the storm surge scenarios were performed to evaluate impacts such as potential breaching of the interstate, erosive forces along underpasses and flooding of the surrounding neighborhoods. The presentation will also include lessons learned and topics for future research.

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How to Cite: Lennon, J. (2014) “Changing Climate and our Infrastructure: The Gulf Coast Phase 2 Case Studies on Transportation Infrastructure Impacts”, National Hydraulic Engineering Conference 2014. 1(2014).