Ennis, B.; Peterson, M.S., and Strange, T.P., 2014. Modeling of inundation characteristics of a microtidal saltmarsh, Grand Bay National Estuarine Research Reserve, Mississippi.
Intertidal saltmarsh habitats are unique productive estuarine systems in that their relative productivity is strongly influenced by the morphology of the landscape and the degree of water inundation. Despite the recognized effect that flooding in saltmarsh intertidal zones has on the natural history of resident fauna and the conservation of the habitat itself, limited data are available with regard to hydrological conditions to conduct proper assessment of these habitats. In this paper we describe a geographic information system–based model that was used to quantify the inundation characteristics of intertidal habitats within the microtidal Crooked Bayou, Grand Bay National Estuarine Research Reserves (GNDNERR), Mississippi, system. Using water levels from a nearby National Oceanic and Atmospheric Administration tide station, inundation characteristics were generated by the model for multiple sample sites and for plots within each site along a common marsh elevation gradient. The derived characteristics generated by the model were used in a principal components analysis to create factor scores depicting flooding conditions. These factor scores were then used as the means of comparison of cumulative inundation characteristics between sites and the plots within sites. Overall, inundation characteristics were found to vary significantly between sampling sites (Kruskal-Wallis, χ2 = 26.13, p < 0.001) and among the plots (Friedman's, χ2 = 19.27, p < 0.001) across the elevation gradient. In general, although the inundation potential of the sampling plots within each site significantly decreased as the marsh elevation gradient increased, there were marked differences among and within sites because of the considerable microtopography patterns we identified that exemplify the microtidal, low-lying intertidal landscape of GNDNERR.