LEVERAGING GEOLOGIC SURFICIAL MAPPING TECHNOLOGY FOR SUSTAINABLE COASTAL DEVELOPMENT

At the onset of a development resurgence, the central Oregon Coast counties are positioned at a pivotal time for creating sustainable growth opportunities. The central Oregon coastal plain is primarily comprised of active or stabilized sand dunes that extend .5-3 miles inland and range in age from present to 111,000 years old. These paleodunes contain various layers of interbedded soils, sand, iron oxides and deflation zones that complicate engineering and hydrologic site assessments. To analyze land use opportunities and risks for Lincoln County in the central Oregon Coast, an integrated Geographic Information System (GIS) data set was created. This data set utilizes new surface mapping of coastal plain deposits with other topographic and hydrologic coverages. To illustrate the importance of the paleodune deposits on the sustainable development of the Oregon Coast we are producing detailed surficial geology maps using a GIS dataset of the paleodunes' distribution, emplacement age, relative cementation, shallow stratigraphy, and associated geotechnical properties. The maps also incorporate other GIS coverages including jurisdictional boundaries, infrastructures, digital elevation models (DEM), surface hydrology, cadastral and known cultural sites. These overlapping coverages demonstrate the unique geospatial relationships between the coastal plain surface deposits and associated foundation soils, groundwater contaminant flow paths, and sensitive upland habitats in the paleodune landscape. The geospatial relationships are the first application of recent surficial mapping within a complete coastal dune system on the Oregon Coast.