Outdoor Glossary: H

habitat
The area where a plant or animal lives and grows under natural conditions.

habitat
The locality i.e., environment in which an organism lives; the place where a species normally lives and grows; the native environment or usual dwelling place of an animal or group of animals

habitat
The place where an organism lives.

habitat capability
The ability of a land area or plant community to support a given species of wildlife.

habitat diversity
A number of different types of wildlife habitat within a given area.

habitat diversity index
A measure of improvement in habitat diversity.

habitat type
A way to classify land area . A habitat type can support certain climax vegetation, both tree and undergrowth species. Habitat typing can indicate the biological potential of a site.

hackle
The part of a fly that imitates the legs of an insect. It is generally made from bird feathers and greatly aids in a dry fly's ability to floa

half-tide level
A plane midway between mean high water and mean low water, also called mean tide level.

halocline
A layer in which the salinity changes significantly (relative to the layers above and below) with depth.

handle
The extension of a reel that forces the spool to turn and retrieve line once it has been turned

harbor
A water area nearly surrounded by land, sea walls, breakwaters or artificial dikes, forming a safe anchorage for ships.

hard defenses
A general term applied to impermeable coastal defense structures of concrete, timber, steel, masonry, etc, which reflect a high proportion of incident wave energy.

harmonic analysis
The mathematical process by which the observed tide or tidal current at any place is separated into basic harmonic constituents.

harmonic analyzer
A machine designed for the resolution of a periodic curve into its harmonic constituents. Now performed by electronic digital computer.

harmonic constants
The amplitudes and epochs of the harmonic constituents of the tide or tidal current at any place.

harmonic constituent
See constituent.

harmonic function
In its simplest form, a quantity that varies as the cosine of an angle that increases uniformly with time. It may be expressed by the formula:y = A cos at in which y is a function of time (t), A is a constant coefficient, and a is the rate of change in the angle at.

harmonic prediction
Method of predicting tides and tidal currents by combining the harmonic constituents into a single tide curve. The work is usually performed by electronic digital computer.

harmonic reduction
Same as harmonic analysis.

harmonic tide plane
Same as Indian spring low water.

hatch
The act of an immature insect transforming into its adult form; also used to describe a large number of adult insects on, near or above the water at the same time (a hatch of insects).

hatching
The process when a fish larva frees itself from the egg membrane

head
(1) A comparatively high promontory with either a cliff or steep face. It extends into a large body of water, such as a sea or lake. An unnamed head is usually called a headland. (2) The section of rip current which has widened out seaward of the breakers, also called head of rip.

head of tide
The inland or upstream limit of water affected by the tide. For practical application in the tabulation for computation of tidal datums, head of tide is the inland or upstream point where the mean range becomes less than 0.2 foot. Tidal datums (except for mean water level) are not computed beyond head of tide.

head stripes
Bold lines on the head.

headland
A land mass having a considerable elevation.

heave
(1) The vertical rise or fall of the waves or the sea. (2) The translational movement of a craft parallel to its vertical axis. (3) The net transport of a floating body resulting from wave action.

heavy sea
A sea in which the waves run high.

hemostats
Surgical pliers

herbivores
wildlife species that eat vegetation.

hibernation
a state of deep "sleep" in which heart beat, respiration, and other bodily functions slow down to conserve energy. Hibernate, vb

hiding area/cover
Vegetation capable of hiding 90% of an adult elk or deer from human's view at a distance of 200 feet or less.

high tide
Same as high water.

high water (HW)
The maximum height reached by a rising tide. The high water is due to the periodic tidal forces and the effects of meteorological, hydrologic, and/or oceanographic conditions. For tidal datum computational purposes, the maximum height is not considered a high water unless it contains a tidal high water.

high water inequality
See diurnal inequality.

high water interval (HWI)
See lunitidal interval.

high water line
The intersection of the land with the water surface at an elevation of high water.

high water mark
A line or mark left upon tide flats, beach, or along shore objects indicating the elevation of the intrusion of high water. The mark may be a line of oil or scum on along shore objects, or a more or less continuous deposit of fine shell or debris on the fore shore or berm. This mark is physical evidence of the general height reached by wave run up at recent high waters. It should not be confused with the mean high water line or mean higher high water line.

high water, full and change (HWF&C)
Same as establishment of the port.

high-output
Highly breathable clothing that offers some amount of weather protection

higher high water (HHW)
The highest of the high waters (or single high water) of any specified tidal day due to the declination Al effects of the Moon and Sun.

higher low water (HLW)
The highest of the low waters of any specified tidal day due to the declination Al effects of the Moon and Sun.

hindcasting
In wave prediction, the retrospective forecasting of waves using measured wind information. See also wave hindcasting.

hindhead
Rear portion of crown. Synonym(s): occiput.

hindneck
Back of the neck. Synonym(s): nape, collar.

hinterland
The region lying inland from the coast.

historic event analysis
Extreme analysis based on hindcasting typically ten events over a period of 100 years.

hog
An exceptionally large fish; also known as a "lunker"; sometimes spelled "h-a-w-g."

home range
the area that an animal uses throughout its lifetime to eat, find shelter, and reproduce.

honey hole
The prime piece of water on a lake or stream; always loaded with fish and usually requiring an oath of sworn secrecy before your buddy takes you to it.

hook
A spit or narrow cape, turned landward at the outer end, resembling a hook in form.

horizon
(1) The line or circle which forms the apparent boundary between Earth and sky. (2) (Geological) A plane in rock strata characterized by particular features, as occurrence of distinctive fossil species. One of the series of distinctive layers found in a vertical cross-section of any well-developed soil.

horizontal diversity
The distribution and abundance of different plant and animal communities or different stages of plant succession across an area of land; the greater the numbers of communities in a given area, the higher the degree of horizontal diversity.

horns
Paired contour feathers arising from head.

Humboldt Current
Same as Peru Current.

hurricane
A cyclonic storm, usually of tropic origin, covering an extensive area, and containing winds in excess of 75 miles per hour.

hydraulic current
A current in a channel caused by a difference in the surface elevation at the two ends. Such a current may be expected in a strait connecting two bodies of water in which the tides differ in time or range. The current in the East River, New York, connecting Long Island Sound and New York Harbor, is an example.

hydrographic datum
A datum used for referencing depths of water and the heights of predicted tides or water level observations. Same as chart datum. See datum.

hydrography
(1) The description and study of seas, lakes, rivers and other waters. (2) The science of locating aids and dangers to navigation. (3) The description of physical properties of the waters of a region.

hydrologic cycle
Also called the water cycle, this is the process of water evaporating, condensing, falling to the ground as precipitation, and returning to the ocean as run-off.

hydrology
The science dealing with the study of water on the surface of the land, in the soil and underlying rocks, and in the atmosphere.