An abrupt vertical change of salinity with depth, usually from fresher to saltier water occurring within a rather narrow horizontal layer; it shows on sonar as a sharp discontinuity and has important effects on distribution of life in the ocean (“pycnocline”).


A sheltered part of a coastal town where ships and boats can safely shelter, load and unload. Often a harbour wall is built out to sea to prevent big waves coming in.

Hard Defenses

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



A place where eggs are hatched under artificial conditions


Threat; condition, which may result from either an external cause (e.g. earthquake, flood, or human activity) or an internal vulnerability, with the potential to initiate a failure mode. A source of potential harm or a situation with a potential to cause loss.


Hard feature ( natural or artificial) forming local limit of longshore extent of a beach.


Where an area of land sticks out into the sea. Headlands are usually made of hard rocks and have cliffs at their edges.

Hedonic pricing:

Valuation technique, which infers a value for environmental quality from rent or property price differentials.

High Tide Line

The line or mark left upon tide flats, beaches, or along shore objects that indicates the intersection of the land with the water's surface at the maximum height reached by a rising tide. The term includes spring high tides and other high tides that occur with periodic frequency, but does not include storm surges in which there is a departure from the normal or predicted reach of the tide due to the piling up of water against a coast by strong winds such as those accompanying a hurricane or other intense storm. The high tide line is a higher elevation than the mean high water line.

High water

The maximum elevation reached by the rising tide; mean high water is the average of such tidal elevations.

High Water Line

In strictness, the intersection of the plane of mean high water with the shore. For specific occurrences, the highest elevation on the shore reached during a storm or rising tide, including meteorological effects.

High Water Line:

The intersection of the plane of mean high water with the shore; the shoreline delineated on nautical charts prepared by the National Ocean Service is an approximation of the high water line.


High water Mark

The level of the sea at high tide (the level of water when the tide is in), usually marked by a line of seaweed and litter.


The land away from the coast which influences the coast including plains, hills, watersheds, water courses, etc (the “uplands”).


Human capital

Human Capital is a category of livelihood assets. It represents the skills, knowledge, capacity to work, and good health that together enable people to pursue different livelihood strategies and achieve their livelihood outcomes. At a household level human capital is a factor of the amount and quality of labour available. This varies according to household size, skill levels, education, leadership potential, health status, etc. Human capital is necessary to be able to make use of the other four types of livelihood assets

Human factors

Human factors: Human factors refer to environmental, organizational and job factors, and human and individual characteristics that influence behaviour in a way which can affect safety.


 An intense tropical cyclone in which winds tend to spiral inward toward a core of low pressure, with maximum surface wind velocities that equal or exceed 33.5 m/sec (75 mph or 65 knots) for several minutes or longer at some points.


 The description and study of seas, lakes, rivers and other waters; the science of locating aids and dangers to navigation; the description of physical properties of the waters of a region.


The science dealing with the properties, distribution, and circulation of water on earth


Hypoxic Waters

 Waters with a low concentration of oxygen.

Hypoxic Waters

 Waters with a low concentration of oxygen