DETAILED MAPPING OF STREAMS AND WETLANDS IN CATOCTIN MOUNTAIN PARK USING TRIMBLE GEO XH (GEOEXPLORER 6000)

Catoctin Mountain Park, a national park populated by second-growth hardwood forests, faces unique management challenges. Staff biologists have prioritized the management of intensive invasive species management and mitigation of the impact of ongoing agricultural activity on the park’s aquatic ecosystems. However, the damage that these stressors have had on the park’s aquatic ecosystems is not fully understood: the park has yet to update their databases and maps of small, seasonal streams and of wetland areas. This GSA Mosaics/Geocorps America project, a partnership between the Geological Society of America and the National Park Service, aims to expand the park’s GIS database of streams and wetlands through detailed field mapping and digitization of aerial photographs.

During the summer of 2013, field mapping work covered several areas that had not been previously mapped. Several portions of the GIS streams layer that had been previously digitized using outdated aerial photos were corrected to reflect the paths of current stream channels. Mapping was conducted using a Trimble Geo XH (Geoexplorer 6000 series) handheld unit connected to a backpack antenna (~1m in length). GPS data was collected using Terrasync (Professional edition, version 5.11). All shapefiles were managed and edited using ArcMap 10. Wetland delineation techniques were used to map the extent of wetland areas in various regions of the park.

Except for the two largest streams in the park—Owens Creek and Big Hunting Creek, which lend their names to two important sub-watersheds in the Upper Monocacy Watershed, a catchment basin that provides potable water for Frederick County—the park’s creeks and wetlands are seasonal and disappear during times of drought. To reflect the seasonality of these streams, the park’s GIS database will need to be updated more frequently in order to more accurately reflect current stream trends.

The park’s stream and wetland maps will be used to augment amphibian habitat mapping and inventory programs initiated by the National Capital Region Network’s amphibian monitoring program. This program, which includes all other national parks within the Washington, D.C. region, is part of a multiyear, multiagency effort to understand the extent to which development and climate change have impacted amphibian populations.