T109 Seeing the True Shape of Earth’s Surface: Applications of Airborne and Terrestrial LiDAR in the Geosciences (Posters)

Monday, 1 November 2010
8:00 AM - 6:00 PM
Hall D

GEOSPATIAL ANALYSIS OF THE DYNAMICS OF A COASTAL SAND DUNE USING TIME SERIES OF LIDAR DATA AND TANGIBLE GEOSPATIAL MODELING SYSTEM (TanGeoMS)

Paper number: T109-3
Program: Technical Sessions
Time: 8:00 AM – 6:00 PM

Authors

Abstract

Jockey’s Ridge State Park, located along the Outer Banks of North Carolina, is home to the largest active sand dune on the Eastern coast of the United States. Several LiDAR surveys have provided data for accurate analysis of its evolution. Previous studies indicated that this large active dune evolved over a relatively short time period, rapidly growing between 1900-1950 and steadily losing elevation from 40m to 22m between 1950-2001, while migrating south at the rate of 3-6m a year. Recent airborne LiDAR surveys allowed us to analyze and quantify the continuing dune evolution using feature and raster based metrics which verified the predicted stabilization of the dune field. The analysis was also used to assess the effectiveness of sand management approaches, such as sand relocation and strategic placement of stabilization fences. In addition to elevation surface evolution, the LiDAR data provided 3D information about the forest growth that further limits sources of sand feeding the dune. Ongoing study combines LiDAR, imagery, historical elevations and land cover data to further investigate the relation between the dune evolution and growth of vegetation, storms, and climate change.

In addition to the dune evolution analysis we have investigated the impact of changes in the dune topography on storm surge flooding using the Tangible Geospatial Modeling System (TanGeoMS). TanGeoMS integrates a 3D laboratory laser scanner, a scaled physical model, and a projector with GRASS GIS. Contours extracted from a LiDAR-based digital elevation model were used to construct a 1:3000 scale model of the dune. The model was then modified by hand and rescanned, allowing for the creation of specific scenario simulations representing different management and natural impacts such as sand relocation or foredune breaches. The results of flooding simulations were then projected over the 3D model providing feedback on the impact of the introduced change and guiding further exploration. LiDAR-based geospatial analysis and TanGeoMS provided valuable results that coastal managers and researchers can use to aid in land-use planning, coastline protection, and emergency response.