Coastal Drainage Area: Generally defined as that component of an entire watershed that meets the following three criteria: 1) it is not part of any EDA or a corresponding FDA; 2) it drains directly into an ocean, an estuary, or the Great Lakes; and 3) it is composed only of the downstream-most HUC in which the head-of-tide is found. For more information see the NOAA Ocean Resource Conservation and Assessment's (ORCA) Coastal Assessment Framework (CAF) Web page.
Estuarine Drainage Area (EDA): "An Estuarine Drainage Area is that component of an estuary's entire watershed that empties directly into the estuary and is affected by tides. EDAs may be composed of a portion of a single hydrologic unit, an entire hydrologic unit, more than one hydrologic unit, or several complete hydrologic units and portions or several adjacent hydrologic units.
"Every EDA has both a land and water component, with the land component comprised of a mainland component and, for certain EDAs, an island component. Overall size and characteristics of these EDAs varies greatly. For example the Chesapeake Bay EDA including its subEDAs along the Mid-Atlantic coast covers 38,200 square miles while several EDAs or subEDAs along the Pacific coast cover 100 square miles or less."
This information was taken from the NOAA ORCA CAF Web page.
Fluvial Drainage Area (FDA): A component of an estuary's entire watershed upstream of the EDA boundary. Less than half the EDAs have corresponding FDAs. FDAs have land components only. For more information see the NOAA ORCA CAF Web page.
Hydrologic Unit Code (HUC): The United States is divided and sub-divided into successively smaller hydrologic units which are classified into four levels: regions, sub-regions, accounting units, and cataloging units. The hydrologic units are arranged within each other, from the smallest (cataloging units) to the largest (regions). Each hydrologic unit is identified by a unique hydrologic unit code (HUC) consisting of two to eight digits based on the four levels of classification in the hydrologic unit system. For more information see the USGS Water Resources Web site.
Instantaneous Field of View (IFOV): The solid angle through which a detector is sensitive to radiation. In a scanning system this refers to the solid angle subtended by the detector when the scanning motion is stopped. Instantaneous field of view is commonly expressed in milliradians. IFOV also refers to the ground area covered by this solid angle (Committee for Earth Observation Satellites).
Minimum mapping unit (MMU): The smallest feature reported in an image. Although an image may have 30-meter pixels, the MMU can be reported at 60-meter pixels. This is frequently done to account for scale differences between analysis and to reduce reporting errors.
Radiance: Total energy radiated by an object of unit area per solid angle of measurement. The standard measurement unit is watts per square meter. This geometric radiation quantity is what is measured by remote sensing devices (Committee for Earth Observation Satellites).
Sea, Lake and Overland Surges from Hurricanes (SLOSH) Model: The SLOSH Model was developed by NOAA's National Weather Service to assess the vulnerability of an area to hurricane storm surge. This model compares the maximum envelope of water to the elevation of the area to predict whether the area will be flooded during a range of storm scenarios. The storm's angle and direction of attack will be critical for modeling different scenarios. The SLOSH Model is one methodology that can be used to assess hurricane storm surge vulnerability. For an example of the SLOSH Model on the South Carolina Coast, see the South Carolina's Coast: A Remote Sensing Perspective on-line CD-ROM.
Storm Surge: A phenomenon that occurs when the winds and forward motion associated with a hurricane and low barometric pressure pile water up in front of the storm system as it moves toward the shore. Storm surge heights and associated waves are dependent on a combination of factors, including the configuration of the continental shelf (narrow or wide), the depth of the ocean bottom, the intensity of the storm, the storm's forward speed, and the storm's direction of movement.
For more information see the South Carolina's Coast: A Remote Sensing Perspective on-line CD-ROM.
Signature Development: Training samples are collected for materials of interest (MOI) and statistically analyzed to derive characteristic reflectance and radiance information for use in identifying similar materials elsewhere in the same digital image or others.
Spectral Signature: The quantitative measurement of the properties of an object at one or several wavelength intervals. Spectral signature analysis techniques use the variation in the spectral reflectance or emittance of objects as a method of identifying the objects (NASA).
Watershed: The region drained by a specific water system (Harcourt).
Wetland: Areas that are inundated or saturated by surface or ground water at a frequency or duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetland generally include playa lakes, swamps, marshes, bogs and similar areas such as sloughs, prairie potholes, wet meadows, prairie river overflows, mudflats, and natural ponds (King 1995, from 40 C.F.R. Section 110.1).
King, J.J. 1995. The Environmental Dictionary and Regulatory Cross-Reference. Third Ed. John Wiley & Sons, Inc.: New York. [All definitions in this dictionary have been reproduced from the Code of Federal Regulations, Title 40, Protection of Environment (40 C.F.R.), revised as of July 1, 1987, and the Federal Register (updates pertaining to 40 C.F.R.) covering the period from July 1, 1987, through June 30, 1994.]
Harcourt Academic Press Dictionary of Science and Technology
Committee on Earth Observation Satellites (CEOS)
NASA Landsat 7 Science Data Users Handbook