A pressure-controlled device which bypasses water at a fire pump to prevent excessive pressures when a nozzle is shut down.

The exterior perimeter of an area within which a specified fire agency has assumed a degree of responsibility for wildland fire control. It may include land in addition to that for which the agency has jurisdiction or contractual responsibility.

A congressionally ratified agreement that provides form and structure to interstate mutual aid. Through EMAC, a disaster-affected state can request and receive assistance from other member states quickly and efficiently, resolving two key issues up front: liability and reimbursement.

A method of controlling a partly dead fire edge by carefully inspecting and feeling with the hand for heat to detect any fire, digging out every live spot, and trenching any live edge.

In the 1978 version of NFDRS, the herbaceous stage approximately 30 days prior to green-up.

Part of a population; that portion of the population that is measured.

The specific dimensions of screw thread employed to coupled fire hose and equipment. American National Standards (NH) have been adopted for fire hose couplings threads in 3/4, 1-1/2, 2-1/2, 3-1/2, 4, 5, and 6-inch sizes.

The order that defines when personnel and/or equipment will be ready for release from an incident.

Total time a fuel can burn and continue to feed energy to the base of a forward-traveling convection column.

A portion of the general fire weather forecast issued on a regular basis during the normal fire season specifically to fit the requirements of fire management needs; i.e., time, areas, and weather elements. These zones or areas are a combination of administrative and climatological areas, usually nearly the size of an individual forest or district.