Hawaii's Watersheds Glossary of Terms

Return to Help

http://www2.hawaii.edu/environment/welcome.html

Algae: A chlorophyll containing plant ranging from one to many cells in size, that lives in fresh or salt water.

Anadromous: Fish that return from salt water to fresh water to spawn (e.g. salmon, steelhead).

Aquatic insect: Insect species whose larval and/or juvenile forms live in the water.

Aquifer: Any underground geological formation containing water.

Bedrock: Unbroken solid rock, overlain in most places by soil or rock fragments.

Benthic: Bottom-dwelling. The plant and animal life whose habitat is the bottom of a sea, lake, or river.

Channelized: The straightening and deepening of streams. These streams are often lined with cement or rock.

Clarity: The clearness of the water in the stream.

Conifers: A cone-bearing evergreen tree or shrub (a pine tree for example).

Cover: Overhanging or instream structures (such as tree roots, undercut streambanks, or boulders) that offer protection from predators, shelter from strong currents, and/or shading.

Current: The velocity (speed) of the flow of water.

Deciduous: A tree which sheds its foliage at the end of the growing season.

Ecosystem: The interacting system of a biological community (plants, animals) and it's non-living environment.

Effluent: The wastewater from a municipal or industrial source that is discharged into the water.

Erosion: The wearing away of the land surface by wind or water.

EPA: Environmental Protection Agency.

Filling: The process of depositing dirt and mud in marshy areas (wetlands) or in the water to create more land. Filling disturbs natural ecological cycles.

Gradient: The slope or steepness of the stream.

Groundwater: The supply of freshwater under the earth's surface in an aquifer or soil.

Habitat: The specific environment in which an organism lives and depends on for food and shelter.

Headwaters: Small creeks at the upppermost end of a stream system, often found in the mountains, that contribute to larger creeks and rivers.

Mass wasting: Downward movement of dry soil and rock caused by gravity (often called slides or avalanches).

Monitor: To measure a characteristic, such as streambank condition, dissolved oxygen, or fish population, over a period of time using uniform methods to evaluate change.

Non-point source pollution: "Diffuse" pollution, generated from large areas with no particular point of pollutant origin, but rather from many individual places. Urban and agricultural areas generate non-point source pollutants.

Nutrient: Any substance, such as fertilizer, phosphorous, and nitrogen compounds, which enhances the growth of plants and animals.

Point source pollution: A discharge of water pollution to a stream or other body of water, via an identifiable pipe, vent, or culvert.

Pool: An area of relatively deep slow water in a stream that offers shelter to fish.

Quality control (QC): The system of checks that are used to generate excellence, or quality, in a program (a monitoring program for example. QC asks if we are doing the right things (in our case are we monitoring the right things to detect changes in water quality).

Reach: For the purposes of this survey, we will refer to the "reach" as a designated length of stream (approx. 50 meters) walked along to record observations and within which a specific monitoring site is located.

Riffle: A shallow, gravely area of streambed with swift current. Used for spawning by some fishes.

Riparian area: An area, adjacent to and along a watercourse, which is often vegetated and constitutes a buffer zone between the nearby lands and the watercourse.

Run: A stretch of fast, smooth current, deeper than a riffle.

Sediment: Fine soil or mineral particles that settle to the bottom of the water or are suspended in the water.

Stormwater runoff: Water that washes off the land after a rainstorm. In developed watersheds it flows off roofs and pavements into storm drains which may feed directly into the stream: often carries concentrated pollutants.

Substrate: The material that makes up the bottom layer of the stream, such as gravel, sand, or bedrock.

Stream corridor: A perennial or intermittent stream, it's lower and upper banks.

Stream mouth: The beginning of a stream, where it empties into a lake, ocean, or another stream.

Suspended sediments: Fine material or soil particles that remain suspended by the current until deposited in areas of weaker current. They create turbidity and, when deposited, can smother fish eggs or aquatic insect larvae. Can be measured with a nephelometer as "total suspended solids" (TSS).

Topographic: The configuration of a surface area including its relief, or relative elevations, and the position of its natural and manmade features.

U.S.G.S: U.S. Geological Survey.

Wetlands: Wetlands are lands where saturation with water is the dominant factor determining the nature of soil development. They also can be indentified by unique plants which have adapted to oxygen-deficient (anaerobic) soils. Wetlands influence stream flows and water quality.

Zoning: To designate, by ordinances, areas of land reserved and regulated for specific uses, such as residential, industrial, or open space.

Return to Help

Return to Hawaii's Watersheds


Glosssary content compiled by Malie Beach, HTML by Eric Capers
Last update July,1997 (Capers)