Visual Resources Glossary

Select a letter from the list below to view glossary terms and acronyms/abbreviations. The agency abbreviation following the definition indicates the definition source.

A B C D E F G H I K L M N O P Q R S T U V W

Ecoregion: A large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions. (BLM)
Edge: The line formed where an object or area begins or ends. Edge serves to define borders, limits, or boundaries. (USFS)
Effect: Environmental consequence that occurs as a result of a proposed action. An effect may be direct (caused by the action and occurring at the same time and place), indirect (caused by the action but occurring later in time or farther removed in distance but still reasonably foreseeable), or cumulative (incremental impacts of the action when added to other past, present, and reasonably foreseeable future actions). In the National Environmental Policy Act of 1969, effect is synonymous with impact. (BLM, NPS)
Enclosed (view type): Enclosed views are bounded by a contiguous group of objects. (NPS)
Enhancement: A management action designed to improve visual quality. (BLM)
Environmental Assessment (EA): A concise public document that a federal agency prepares under the National Environmental Protection Act to provide sufficient evidence and analysis to determine whether a proposed action requires preparation of an Environmental Impact Statement, or whether a Finding of No Significant Impact can be issued. An EA must include brief discussions on the need for the proposal, the alternatives, the environmental impacts of the proposed action and alternatives, and a list of agencies and persons consulted. (NPS)
Environmental Impact Statement (EIS): An environmental impact assessment document required of federal agencies by the National Environmental Protection Act for major proposals or legislation that will or could significantly affect the environment. An EIS must include a description of the proposed action, the environmental setting, and potentially affected areas. It must also include an analysis of reasonable alternatives to the proposed action, all environmental impacts related to the proposed action and its alternatives, and ways to identify, reduce, or avoid adverse impacts. (NPS)
Equivalent focal length: The zoom length needed for a digital SLR to have the same zoom length as a 35mm film camera. (FHWA)
Existing scenic integrity: Current state of the landscape, considering previous human alterations. The existing visual condition. (USFS)
Expected image: A mental picture that a person expects to see in a national forest. (USFS)