Coastal Louisiana landscape and storm surge evolution: 1850–2110

Abstract

Storm surge models are constructed to represent the Louisiana coastal landscape circa 1850, 1890, 1930, 1970, 1990, 2010, 2030, 2050, 2070, 2090, and 2110. Historical maps are utilized to develop models with past landscapes while a continuation of recent landscape trends is assumed for future models. The same suite of meteorological wind and pressure fields is simulated with each storm surge model. Simulation results for 1850 and 1890 demonstrate minimal change in storm surge characteristics along the Louisiana coast. A mean maximum storm surge height increase of 0.26 m from 1930 to 2010 is quantified within the sediment-abundant Atchafalaya-Vermilion coastal basin, while increases of 0.34 m and 0.41 m are quantified within sediment-starved Terrebonne and Barataria, respectively. Future mean maximum storm surge heights increase across these three coastal basins by 0.67 m, 0.55 m, and 0.75 m, indicating negligible differences from 2010 to 2110, regardless of sediment availability. Results indicate that past changes in the Louisiana coastal landscape and storm surge were a consequence of local land and river management decisions while future changes are dominated by relative (subsidence and eustatic) sea level rise. Projecting landscape and surge changes beyond 50 years could aide policy makers as they work to enhance resilience across coastal Louisiana. Similar analyses could be conducted for other deltas across the world, such as the Ganges, that are experiencing challenges comparable to those of the Mississippi River Delta.