Areas on aerial photos that show up as dark blue, dark grey, or black and are indicative of saturated soil conditions.
Contributing Drainage Area
Specific landscape features that transmit water to wetlands (e.g., surface drainage area, groundwater recharge areas, stormwater outfalls).
Digital Elevation Model (DEM)
A digital file consisting of terrain elevations for ground positions at regularly spaced horizontal intervals.
The process of converting features on a paper map into digital format using a trace methodology, which results in the creation of a spatial dataset.
Direct Wetland Impacts
Wetland loss or degradation resulting from activities that occur within wetlands, such as dredging, filling and draining. Activities that cause direct impacts are largely regulated through the federal and state wetland permitting process.
A transition area between two adjacent, but different plant communities.
Facultative Wetland Plants
Species that usually occur in wetlands (approximately 67% - 99% probability), but also occur in non-wetland areas (approximately 1% - 33% probability).
Geographic Information Systems (GIS)
A system that integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Factors that influence how wetlands function, including geomorphic setting, water source, and hydrodynamics.
A plant that grows wholly or partially submerged in water.
Information collected and processed from across the electromagnetic spectrum. Spectral signatures (unique “fingerprint” left by specific objects) enable identification of materials that make up a scanned object.
Indirect Wetland Impacts
Impact to wetlands caused by inputs of stormwater and pollutants generated by land development or other activities within the wetland CDA.
Interferometric Synthetic Aperture Radar (IFSAR)
A radar technique that uses two or more synthetic aperture radar (SAR) images to generate surface elevation using differences in the phase of waves returning to the satellite or aircraft.
Light Detection and Ranging (LiDAR)
A remote sensing technique that measures properties of pulsed laser light reflected from objects to determine their position, velocity, and other information.
Minimum Mapping Unit
The minimum size or dimensions for features to be mapped as lines or areas for a given map scale.
Obligate Wetland Plants
Species that occur almost always in wetlands under natural conditions (greater than 99% probability), but which may also occur rarely in non-wetlands (less than 1% probability).
Gathering and recording information about objects without actual contact through the use of such techniques as photography, infra-red imagery, and radar.
A cell or set of spatially connected cells that cannot be assigned flow direction in a raster elevation dataset. This can occur when all neighboring cells are higher than the processing cell or when two cells flow into one another. Sinks can indicate areas where water is likely to pond, but can also be an error in the dataset.
The ability to see three dimensionally by using two views of a single object from slightly different positions typically through the use of an optical aid known as a stereoscope.
Stormwater Treatment Practices
A structural or non-structural practice designed to temporarily store or treat stormwater runoff in order to mitigate flooding, reduce pollution, and provide other amenities (also called a Best Management Practice – BMP).