The FEMA Map Service Center serves as FEMA's distribution node for flood information maps supporting the National Flood Insurance Program. Data related to these maps comes in five basic forms:
- Flood Information Rate Map (FIRM, or just "Flood Map"): Is the official map of a community on which FEMA has delineated both the special hazard areas and the risk premium zones applicable to the community. It is a paper map, typically covering a large area.
- FIRMettes: A FIRMette is a full-scale section of a FIRM that individuals can create online and is formatted to fit on printers commonly found in offices.
- Digital Q3 Data: Q3 Flood Data is a digital representation of certain features of FEMA's FIRMs, intended for use with desktop mapping and Geographic Information Systems (GIS) technology. Digital Q3 Flood Data has been developed by scanning the existing FIRM hardcopy and vectorizing a thematic overlay of flood risks. The vector Q3 Flood Data files contain only certain features from the existing FIRM hardcopy.
- Digital Flood Information Rate Map (DFIRM): This FEMA GIS database stores the digital data used in the map production process, as well as the backup engineering data for the floodplain studies. This database provides a standard, systematic method for FEMA to distribute comprehensive details of its flood studies to the public in a digital format.
- National Flood Hazard Layer (NFHL): The NFHL is a computer database that contains flood hazard map information from FEMA’s Flood Map Modernization program. This data comes from the DFIRM database and Letters of Map Revision (LOMRs).
While most items above are available either through an online viewer or desktop application, only NFHL data can be incorporated into Google Earth, or brought into another mapping application as a WMS.
- To visit the FEMA Map Service Center - go here
- Software for refining related data within various GIS's can be found here.
- USGS publishes a complementary modeling program called the National Streamflow Statistics (NSS) program which can be found here.
Comment: The above dizzying collection of links and information are reflective of the massive change taking place at FEMA as it transitions from hand drawn paper flood maps to digital data that can be modeled and analyzed. While they have made great progress, there is still a long way to go.