Towards Improving Infrastructure Resilience to Tropical Cyclone Induced Flooding

According to a new report by First Street Foundation nearly 25% of critical infrastructures in the United States are at risk of being inundated by flooding and becoming inoperable. Texas, the largest state in the continental U.S is frequented by tropical cyclones (TCs) due to its proximity to the Gulf of Mexico. Hurricane Harvey in 2017, which was the most significant TC event in Texas, caused catastrophic flooding in Harris and Galveston counties in Texas. It caused extensive power outage in this region, affecting more than 2 million people. Hurricane Rita that hit the Texas coast in 2005, caused the unfortunate death of 24 nursing home evacuees because of the traffic gridlock during evacuation in the Houston area. Studies suggest an increase in the intensities of the strongest storms and increased rainfall rates in response to climate change leading to more severe flooding events. Here we demonstrate an interdisciplinary effort towards making our critical infrastructures more resilient and mitigating the cost of such flooding events. We assess the flooding caused by 28 TCs including 12 hurricanes that impacted Texas between 1993 and 2018. Using the streamflow from Version 2.0 of the NOAA National Water Model Reanalysis dataset and applying the Height Above Nearest Drainage (HAND) flood mapping methodology, we estimate the flood height at electrical substations, hospitals and nursing homes in Texas. Optimization models are used to provide substation hardening strategies and patient evacuation strategies to enhance resilience to flooding.