Geospatial model output of the coastal wetland landscape change modeling under two projected sea level rise scenarios along the Texas Coast

The Texas coast is a system of barrier islands, lagoons, estuaries, plains, and rivers on a low-lying coastal plain with gently sloping topography. Embedded in this natural and dynamic system are a variety of human developments and activities including oil and gas production, heavy industry, shipping, commercial fishing, recreational fishing, agriculture, tourism, and small and large communities dotted throughout the landscape. The natural systems of the coastal plain, however, are dynamic and subject to sudden hazards such as floods, storm winds, storm surge, and erosion superimposed on longer-term processes of ongoing erosion caused by sediment supply changes, shifting habitats, sea level rise (SLR), and climate change. Given the vulnerability of the Texas coast, this study assesses the impacts of relative sea level rise (RSLR) and associated enhanced storm surge to better understand the relative susceptibility to negative impacts on the natural and built environments.

This study is part of the third publication of the Texas Coastal Resiliency Master Plan (TCRMP) published in April 2023. TCRMP is an ambitious coastal planning effort by the Texas General Land Office (TGLO) to make the Texas coast more resilient to hazards. For this study, the Harte Research Institute (HRI) developed a dynamic modeling framework to assess quantitative information regarding the impacts of SLR and associated enhanced future storm surge caused by higher sea levels and changes in land cover. For the 2023 TCRMP, two SLR scenarios are modeled - Intermediate-Low scenario (0.5 m of SLR by 2100) and Intermediate-High scenario (1.5 meters of SLR by 2100). The relative component of sea level rise is determined on a regional basis by deriving an average trend from long-term records of coastal tide gauges. This study employs the Sea Level Affecting Marshes Model (SLAMM) to model the possible effects of sea level rise on coastal habitats under two SLR scenarios. This land cover change model provides baseline conditions and predicts future landscape trends based on rising sea levels. The model takes into account key processes that affect the distribution of environments on the coast, such as erosion, vertical accretion, inundation, and saltwater intrusion.

This dataset contains the present land cover based on National Wetland Inventory (NWI) and predicted 2100 land cover with two SLR scenarios from the SLAMM modeling for 4 coastal planning regions covering the Texas coast. These maps illustrate the areas where current critical environments are, areas where those environments will be lost or gained in 2100 under different SLR scenarios, as well as areas that will become new environments but are currently undeveloped dry land. The results of the SLAMM model show that in this century, with no mitigating action taken, significant portions of the Texas coast will be at risk of land loss, as current habitats and low-lying areas around communities are converted into open water.