1987 Wetland Delineation Manual - The Wetlands Regulation Center

Wetland Delination Manual, 1987 80
Flooded - A condition in which the soil surface is temporarily covered with flowing water from
any source, such as streams overflowing their banks, runoff from adjacent or surrounding
slopes, inflow from high tides, or any combination of sources.
Flora - A list of all plant species that occur in an area.
Frequency (inundation or soil saturation) - The periodicity of coverage of an area by surface
water or soil saturation. It is usually expressed as the number of years (e.g. 50 years) the soil is
inundated or saturated at least once each year during part of the growing season per 100 years
or as a l-, 2-, 5-year, etc., inundation frequency.
Frequency (vegetation) - The distribution of individuals of a species in an area. It is
quantitatively expressed as
Number of samples containing species A X 100
Total number of samples
More than one species may have a frequency of 100 percent within the same area.
Frequently flooded - A flooding class in which flooding is likely to occur often under normal
weather conditions (more than 50-percent chance of flooding in any year or more than 50
times in 100 years).
Gleyed - A soil condition resulting from prolonged soil saturation, which is manifested by the
presence of bluish or greenish colors through the soil mass or in mottles (spots or streaks)
among other colors. Gleying occurs under reducing soil conditions resulting from soil
saturation, by which iron is reduced predominantly to the ferrous state.
Ground water - That portion of the water below the ground surface that is under greater
pressure than atmospheric pressure.
Growing season - The portion of the year when soil temperatures at 19.7 inches below the soil
surface are higher than biologic zero (5' C) (US Department of Agriculture - Soil Conservation
Service 1985). For ease of determination this period can be approximated by the number of
frost-free days (US Department of the interior 1970).
Habitat - The environment occupied by individuals of a particular species, population, or
community.
Headwater flooding - A situation in which an area becomes inundated directly by surface
runoff from upland areas.
25 February 1997 Environmental Techncal Services Co. 834 Castle Ridge Rd Austin, Texas 78746