Assessment of Future Flood Hazards for Southeastern Texas: Synthesizing Subsidence, Sea-Level Rise, and Storm Surge Scenarios

Recent hurricanes highlight shortcomings of flood resilience plans in Texas that can worsen with climate change and rising seas. Combining vertical land motion (VLM) with sea-level rise (SLR) projections and storm surge scenarios for the years 2030, 2050, and 2100, we quantify the extent of flooding hazards. VLM rates are obtained from GNSS data and InSAR imagery from ALOS and Sentinel-1A/B satellites. VLM is resampled and projected on LIDAR topographic data, then multiple inundation and flooding scenarios are modeled. By the year 2100, over 76 km(2) are projected to subside below sea level. Subsidence increases the area of inundation over SLR alone by up to 39%. Under the worst-case composite scenario of an 8-m storm surge, subsidence, and the SLR RCP8.5, the total affected area is 1,156 km(2). These models enable communities to improve flood resiliency plans.