Glossary

Alternative crops Crops that have not been typically planted in the Walker Basin, but require less water or are more efficient at using water.

Benthic macro­invertebrates Organisms without backbones that live in or on the sediments of a body of water, such as clams and immature insects like stoneflies and mayflies.

Biomass production Certain crops, such as switchgrass, that are fast-growing and cost-efficient can be used to make fuels such as ethanol, an alternative to petroleum-based fuels.

Cheatgrass (Bromus tectorum)An annual grass native to Europe and parts of Africa and Asia that has invaded areas of western North America.

Economic impact The effect of decisions, policies or events on the employment rates and/or incomes of an area.

Groundwater Water located beneath the ground surface in the soil or rock spaces.

Headwater The place from which a stream or river originates.

Hydrograph Graph showing the discharge of a river over time.

Hydrology The study of the quantity, distribution and movement of water.

Invasive species A non-native species whose introduction causes, or is likely to cause, economic or environmental harm.

Irrigation scheduling The decision of when and how much water to apply to a field with the intent of maximizing water use efficiency.

Market development A process for developing business by entering new segments of the market or converting non-users into users.

Mesic An area with moderate or a well-balanced supply
of moisture.

Plant community A collection of plant species within a geographic area that is influenced by soil type, topography, climate and human disturbance.

Riparian Area of interface between the land and a river or stream. Because of their proximity to water, plant communities in riparian areas are often much different than the surrounding upland area.

Salinity The saltiness, or dissolved salt content, of a body of water or soil.

Satellite imagery Photographs of the Earth from an orbiting satellite. These images can record different spectral ranges of light: the visible light spectrum; light of higher energy than the visible spectrum (ultraviolet); or lower energy (infrared or heat).

Surface water Water that collects on the ground, including streams, rivers, lakes, wetlands and oceans.

Tamarisk Comprises about 50-60 species of deciduous shrub or small tree native to Eurasia and Africa that have very long taproots allowing it access to deep groundwater; considered to be an invasive species in the Walker Basin.

Taproot An enlarged root that grows vertically downward (like a carrot) which can serve as storage for energy or to provide access to deep water resources.

Teff An annual grass native to the northern Ethiopian Highlands.

Water rights The right to use a specified amount of water from a particular source (e.g., river, stream, pond, etc.).

Water savings An amount of water that can be saved as a result of changing water-use practices, for example, switching to crops that require less water.

Water table The top of an underground surface in which the soil or rocks are permanently saturated with water, separating the groundwater zone that lies below it from the zone of aeration that lies above it.

Xeric An area or environment that is extremely dry.

Zone of aeration The area above the water table where spaces between rocks and sediments contain both air and water.