The Magazine for|
Esri Software Users
Coming to Terms
- Angle of Repose
- A measurement of the steepest angle of a surface at which loose material such as soil will remain in place rather than sliding or crumbling. The actual angle will vary depending on the nature of the material.
- Doppler Radar
- A special kind of radar system that measures the distance and direction of rain. The system uses a high-powered rotating antenna to send out pulses of radio waves. The amount needed for pulses to bounce off falling rain and return to the source is used to calculate distance and direction.
- Federal Emergency Management Agency (FEMA)
- This independent agency of the federal government was founded in 1979 to protect the people, property, and infrastructure of the United States from all types of hazards through a comprehensive management program of mitigation, preparedness, response, and recovery.
- Flood Insurance Rate Maps (FIRM)
- Paper maps issued by FEMA that identify areas of 100-year flood hazard in communities based on detailed or approximate analyses. All the digital data needed to create paper FIRM maps is available in electronic format from Digital Flood Insurance Rate Maps (DFIRM).
- Flow Direction
- A parameter in hydrologic modeling that is determined by finding the direction of steepest descent from each cell. The distance is determined between cell centers.
- Incident Command System
- A scalable model for on-scene emergency management that provides a means to coordinate the efforts of individual agencies.
- The study of the location, frequency, and magnitude of earthquakes.