Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. The USGS provides these maps “as-is” for a quick reference, emergency planning tool but assumes no legal liability or responsibility resulting from the use of this information. Although USGS intends to make this server available 24 hours a day, 7 days a week, timely delivery of data and products from this server through the Internet is not guaranteed. Inundated areas shown should not be used for navigation, regulatory, permitting, or other legal purposes. The legacy mapper is located here, and is slated to be decommissioned once historic flood information is added to this interface. The FIM Mapper helps communities visualize potential flooding scenarios, identify areas and resources that may be at risk, and enhance their local response effort during a flooding event. Users can also access historical flood information and potential loss estimates based on the severity of the flood.
The FIM Mapper allows users to explore the full set of inundation maps that shows where flooding would occur given a selected stream condition. Welcome to the USGS Flood Inundation Mapper. More information about the Flood Inundation Mapping Program can be found here. Location (AHPS forecast point) throughout the forecast period (every 6 hours and 3 to 5 days out in many locations).įor more information on AHPS forecasts, please see:įlood inundation map services can be found here. Proceeds downstream, and (3) predict the flow and stage (water-surface elevation) for the stream at a given
The amount of runoff generated by precipitation and snowmelt, (2) simulate the movement of floodwater as it Timing of water flowing through selected stream reaches in the United States. The NWS uses forecast models to estimate the quantity and With National Weather Service (NWS) river forecasts, the user should be aware of additional uncertainties that mayīe inherent or factored into NWS forecast procedures.
If this series of flood-inundation maps will be used in conjunction These maps will vary with the accuracy of the digital elevation model used to simulate the land surface.Īdditional uncertainties and limitations pertinent to this study are described in the document accompanying this The accuracy of the floodwater extent portrayed on Stem river, or backwater from localized debris or ice jams. Additional areas may be flooded due to unanticipatedĬonditions such as: changes in the streambed elevation or roughness, backwater into major tributaries along a main Water-surface elevations and inundation boundaries shown. Streamflows along the modeled reach to vary from those assumed during a flood, which may lead to deviations in the Unique meteorological factors (timing and distribution of precipitation) may cause actual Hydraulic modeling, assuming unobstructed flow, and using streamflows and hydrologic conditions anticipated at Water-surface elevations along the stream reaches were estimated by steady-state The flood boundaries shown were estimated based on water stages (water-surface elevations) and streamflowsĪt selected USGS streamgages.
Maps represent the boundaries of inundated areas with a distinct line, some uncertainty is associated with these
Uncertainties and Limitations for Use of Flood-Inundation Maps