Ravine Definitions

Definitions for Ravine Restoration

Posted by Zach Kolman from Mr. Hill's Environmental Science class

Riffles - A fast-flowing, shallow part of a stream.

Gabian baskets - In civil engineering, gabion wall is a retaining wall made of rectangular containers (baskets) fabricated of thick galvanized wire, which are filled with stone and stacked on one another, usually in tiers that step back with the slope rather than vertically. They may be used to direct the force of a flow of flood waters around a vulnerable structure. Gabions are also used as fish barriers on small streams.

Aeration - The process by which air is circulated through, mixed with or dissolved in a liquid or substance.

Substrate - The earthy material that exists in the bottom of a marine habitat, like dirt, rocks, sand, or gravel.

Dissolved Oxygen - A relative measure of the amount of oxygen that is dissolved or carried in a given medium. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water.

Turbidity - The cloudiness or haziness of a fluid caused by individual particles (suspended solids) that are generally invisible to the naked eye, similar to smoke in air.

Spawning - Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning.

Eddy - A current at variance with the main current in a stream of liquid or gas, especially one having a rotary or whirling motion.

Alluvial Material - Alluvial soils are soils that consist of earth and sand left behind on land which has been flooded or where a river once flowed.

Watershed - A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.

Channel - The physical confine of a river, slough or ocean strait consisting of a bed and banks.

Benthos - The community of organisms which live on, in, or near the seabed, also known as the benthic zone.

Confluence - The meeting of two or more bodies of water. Known also as a conflux, it refers either to the point where a tributary joins a larger river, called the main stem, or where two streams meet to become the source of a river of a new name.

Dredging - An excavation activity or operation usually carried out at least partly underwater, in shallow seas or fresh water areas with the purpose of gathering up bottom sediments and disposing of them at a different location.

Culvert- A device used to channel water. It may be used to allow water to pass underneath a trail, road, railway, or embankment. Culverts can be made of many different materials; steel, polyvinyl chloride (PVC) and concrete are the most common.

Fry- A stage in the spawn cycle of aquatic animals.

Macroinvertebrate - An invertebrate that is large enough to be seen without the use of a microscope.

Hydrology - The study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability.

Point versus Nonpoint pollution - Nonpoint source pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrologic modification. A single identifiable source of air, water, thermal, noise or light pollution. A point source has negligible extent, distinguishing it from other pollution source geometries.

Riparian - Relating to or living or located on the bank of a natural watercourse (as a river) or sometimes of a lake or a tidewater.

Riprap - Rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour, water or ice erosion.

Snag - A standing, dead or dying tree, often missing a top or most of the smaller branches. In freshwater ecology it refers to trees, branches, and other pieces of naturally occurring wood found sunken in rivers and streams; it is also known as coarse wood debris.

Streamflow - The flow of water in streams, rivers, and other channels, and is a major element of the water cycle. It is one component of the runoff of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hill slopes, from groundwater flow out of the ground, and from water discharged from pipes.