REMOTE SENSING APPLICATIONS FOR CRITICAL ZONE MANAGEMENT IN SOUTH CAROLINA, USA

Salt marshes are remarkably valuable wetland ecosystems that provide a range of ecosystem services to the coastal regions. Acting as a buffer between land and open water, they offer flood and storm protection, pollution remediation, atmospheric carbon sequestration, and habitat and spawning grounds for a variety of commercially and ecologically important species of fish and invertebrates. In the United States, protective environmental legislation and regulations have been enacted over the past decades at all levels of government to limit loss and degradation of these areas. The Federal Coastal Zone Management Act of 1972 offers support for the implementation of state-level coastal management programs. In conjunction with this legislation, the State of South Carolina developed a coastal management program in 1979. This program is administrated by the Office of Ocean and Coastal Resource. Through defined regulatory goals, the OCRM inventories its critical environmental assets, including coastal marshes, for use in environmental permitting decisions. In 2007 the OCRM developed a GIS-based method using traditional, airplane-obtained remote sensing imagery to inventory South Carolina’s coastal marshes. This marsh product has become the basis for the Critical zone in the State of South Carolina.

Technological improvements in imaging and digital mapping over the past ten years allow for quicker, almost instantaneous imagery production in small scale areas. This study assesses uses both NAIP imagery and unmanned aerial vehicles for a precise, flexible, and cost-effective way of inventorying and assessing South Carolina’s coastal salt marshes. The use of LiDAR fusion (DEM and Imagery) techniques that have become more prevalent in vegetation classification studies. This project was successful in inventorying salt marsh extent at a county-level. The use of drone imagery over areas of interest allowed for the quantification of previously misclassified marsh zones likely due to resolution concerns and mixed pixels. UAVs offer the ability to perform site-specific ecosystem assessments on-demand or at scheduled intervals with limited concern for atmospheric conditions. Using UAVs for wetland monitoring provides a low-cost method for restoration projects that get abandoned due to concerns about time or money.