Inundation model as an aid for predicting ecological succession on newly-created deltaic land associated with Mississippi River diversions: Application to the wax lake delta

A numerical model to predict ecological succession in deltaic environments has been developed in the context of the NCED (National Center for Earth-surface Dynamics) multidisciplinary effort on coastal restoration in Louisiana, where a considerable amount of land loss has been recorded in the last decades. The previous modeling effort of the NCED group resulted in a "land-building model," i.e. a model of delta morphodynamics that has been applied to simulate the effects of few "big" controlled diversions of the Mississippi River at engineering time scales. Along much of the Louisiana coast, the habitat is mainly controlled by two parameters, the frequency of inundation and the salinity. The inundation model outlined here predicts frequency of inundation by means of a coupling of the overall structure of the land-building model with considerations of the statistics of elevation variation in newly-created land, as well as the interannual variability of flow discharge and sea level. Testing and validation of the inundation model are currently in progress on the Wax Lake Delta, a delta building into the Gulf of Mexico, which has been monitored since its formation in the 1970s. Future refinements to the model will include handling of the effects of 1) salinity variation, 2) vegetation on sediment transport and deposition and 3) the formation and consumption of organic soil.