MODELING CLASSIFYING RIPARIAN ECOTONES VIA GIS UTILIZING GEOPHYSICAL AND VEGETATIVE INPUTS: A NEW APPROCH

摘要

Riparian ecotones are dynamic, transitional ecosystems between aquatic and terrestrial ecosystems with well-defined vegetation and soil characteristics. Development of a geospatial model to delineate riparian ecotones, because of their high variability, is challenging. However, there are two primary factors that all riparian ecotones are dependent on: the watercourse and its associated floodplain. Previous approaches to riparian boundary delineation have utilized fixed width buffers, but this methodology has proven to be inadequate as it only takes the watercourse into consideration and ignores critical geomorphology, associated vegetation, and soil characteristics. Our approach offers advantages over previously used methods by utilizing: the geospatial modeling capabilities of ArcMap GIS; a better sampling technique along the water course to accurately map the 50-year flood plain; the incorporation of National Wetland Inventory (NWI) and Soil Survey Database (SSURGO) data to delineate adjacent areas beyond the 50-year flood plain; and the utilization of National Land Cover Data (NLCD) and Cropland Data Layer (CDL) data. An accuracy assessment is performed to assess the impact of various DEM spatial resolutions, and positional inaccuracies of National Hydrography Dataset (NHD) streams on the delineated riparian ecotone boundary. The result of this study is a robust and automated GIS based model attached to ESRI ArcMap as a toolbox to delineate and classify variable-width riparian ecotones utilizing spatial data readily available from government agencies and geospatial clearinghouses.