About Natural Hazard Maps


About Global Flood Map


Climate change, globalization and urbanization are driving factors behind flood events and their consequences. As a company dedicated to helping its large commercial and industrial property clients manage their risk and insure operating resilience, FM Global has conducted extensive research—building on the data and experience of noted governmental and research organizations—to develop a Global Flood Map that identifies areas exposed to moderate- or high-hazard flooding.

In addition to historical flood data, the Global Flood Map is derived from physically based hydrology and hydraulic scientific data, which accounts for variable external factors such as rainfall, evaporation, snowmelt and terrain. The Global Flood Map is particularly valuable in parts of the world where local or regional flood maps are inconsistent or unavailable. The Global Flood Map currently displays high (100-year) and moderate (500-year) hazard flood zones via a 90 x 90 meter grid.

  • Flood Zone Legend

    • High Hazard (Pink)
      Locations in a 100-year flood zone have at least a 1 percent chance of experiencing a flood each year.
    • Moderate Hazard (Yellow)
      Locations in a 500-year flood zone have at least a 0.2 percent chance of experiencing a flood each year.
  • Frequently Asked Questions


    Q: What makes our Global Flood Map unique?

    A: The Global Flood Map is based on a physical model. The model recreates what actually happens when rain falls or snow melts by incorporating phenomena such as soil infiltration, water runoff and evaporation. This model is then calibrated against known river flows for accuracy.

    Q: How should the Global Flood Map be used?

    A: The Global Flood Map provides quick information on whether a location is in or out of a potential flood zone, and may be particularly helpful in areas of the world where other flood maps or resources are not readily available. It is an initial flood assessment tool that is not intended to replace more detailed local flood resources or a hydrological study. For more information on flood prevention, please refer to FM Global Property Loss Prevention Data Sheet 1-40, Flood. You can subscribe to the FM Global Property Loss Prevention Data Sheets at www.fmglobal.com/datasheets. Flood abatement solutions, in the form of FM Approved products, can be found in our Approval Guide at approvalguide.com.

    Q: Why does the Global Flood Map show “blocks” when zooming in?

    A: FM Global has chosen to display the true resolution (i.e., the “blocky” appearance) with the grid data available. Although “smoothing” techniques could be applied to the contours to offer the appearance of higher resolution, it would be done at the expense of accuracy.

    Q: Are all rivers and water conditions covered by the Global Flood Map?

    A: No. Rivers with watersheds less than 39 square miles (101 square kilometers) are not included. The map also does not account for storm surges or local storm water runoffs. And like most flood maps, it does not recognize levees, bridges and culverts, and does not account for dams and reservoirs.

    Q: The address I searched for is in a flood zone. What can I do?

    A: FM Global offers guidance for flood prevention and mitigation in FM Global Property Loss Prevention Data Sheet 1-40, Flood. (Register to receive FM Global data sheets at fmglobal.com/datasheets. Flood abatement solutions, in the form of FM Approved products, can be found in our Approval Guide at approvalguide.com.)

  • Excluded Features

    • Storm surge and storm water runoff; rivers emptying into tidal waters assume high tide as boundary condition
    • Bridges, levees, dams, reservoirs and culverts
    • Rivers with watersheds less than 39 square miles (101 square kilometers)

    Coverage
    Worldwide, excluding areas north of 60 degrees latitude in North America, Asia, and Hawaii and small islands.

    Digital Elevation Model Accuracy
    Vertical elevation accuracy of +/- maximum of 13 feet (4 meters) for Shuttle Radar Topography Mission, or fewer than 13 feet for other sources.

    Vertical Datum
    NAVD1988 in the United States, EDM96 GEOID elsewhere. Digital Elevation Model Data Source National Elevation Dataset (NED) in the U.S. ‎[1], National Finnish DTM in Finland ‎[2], ASTER in areas north of 60 degrees latitude outside of Finland ‎[3], Geoscience Australia 25 meters DEM in Australia ‎[4], and Shuttle Radar Topography Mission elsewhere ‎[5], all averaged at approximately 90 x 90 meter grid.

    Models
    Used Hillslope River Routing (HRR) catchment-based hydrologic model, and 2D finite-volume hydrodynamic model with inundation areas delineated on a 90 x 90 meter grid.

    Hydrologic Model Input Data
    HydroSHEDS flow directions ‎[6], Precipitation CFS v2 NCEP ‎[7], GlobCover 2009 v2.3 for land cover ‎[8], and re-gridded HWSD v1.1 for soil ‎[9].

    Visual Representation of River Centerlines
    OpenStreetMap ‎[10]

    Gauges
    USGS ‎[11], Global Runoff Data Centre (GRDC) ‎[12], and Satellite discharge data / River Watch ‎[13].

  • Data Sources

    • U.S. Geological Survey, 2002, National Elevation Dataset. Retrieved in 2015.
    • National Land Survey of Finland. Retrieved in February 2016.
    • NASA LP DAAC, 2015, ASTER Level 1 Precision Terrain Corrected Registered At-Sensor Radiance. Version 3. NASA EOSDIS Land Processes DAAC, USGS Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota (https://lpdaac.usgs.gov), accessed January 1, 2014, at http://dx.doi.org/10.5067/ASTER/AST_L1T.003.
    • Geoscience Australia (2015), Digital Elevation Model (DEM) 25 Metre Grid of Australia derived from LiDAR, GA: Canberra, ACT, Australia.
    • USGS (2004), Shuttle Radar Topography Mission, all 3 Arc Second scenes, Filled Finished-B 2.0, Global Land Cover Facility, University of Maryland, College Park, Maryland, February 2000. These data are distributed by the Land Processes Distributed Active Archive Center (LP DAAC), located at USGS/EROS, Sioux Falls, South Dakota, USA. http://lpdaac.usgs.gov.
    • Lehner, B., Verdin, K., Jarvis, A. (2008): New global hydrography derived from spaceborne elevation data. Eos, Transactions, AGU, 89(10): 93-94.
    • Saha, S., et al. (2010), NCEP Climate Forecast System Reanalysis (CFSR) 6-hourly Products, January 1979 to December 2010, Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory, Boulder, Colorado, USA. Accessed January 1, 2012.
    • The MODIS global land cover data product was retrieved from the online Data Pool, courtesy of the NASA Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota, USA. https://lpdaac.usgs.gov/data_access/data_pool
    • Wieder, W.R., J. Boehnert, G.B. Bonan, and M. Langseth. 2014. Re-gridded Harmonized World Soil Database v1.2. Data set. Available online [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA. http://dx.doi.org/10.3334/ORNLDAAC/1247
    • OpenStreetMap contributors. E.T. Seton Park (Map). OpenStreetMap. Retrieved September 21, 2016.
    • U.S. Geological Survey, 2015, National Water Information System data available on the World Wide Web (USGS Water Data for the Nation), accessed January 10, 2015, at http://waterdata.usgs.gov/nwis/.
    • The Global Runoff Data Centre, 56068 Koblenz, Germany.
    • Brakenridge, G.R., De Groeve, T., Kettner, A., Cohen, S., and Nghiem, S. V., date of display, River Watch, University of Colorado, Boulder, Colorado, USA http://floodobservatory.colorado.edu/DischargeAccess.html

About China Earthquake Risk Map


FM Global is dedicated to helping its clients manage their risk and ensure operating resilience. By conducting extensive research, FM Global is building on the data and experience of noted governmental and research organizations to develop earthquake maps that identify seismic risk.

The FM Global China Earthquake Risk Map was created using better data and more robust evaluation methods than were previously available. Our understanding of earthquake hazard (the intensity of shaking at a site) and earthquake risk (how shaking affects the built environment) is continually evolving and improving due to:

  • Better earthquake source data (e.g., active faults and historical earthquake catalogs), modeling methodology, and ground motion prediction equations that more accurately represent how shaking changes as it radiates away from the earthquake source.
  • Revised methods to extract local site (soil) conditions from general geologic data, and updated factors that more accurately account for amplification of bedrock shaking by those local site conditions.
  • Studies that allow development of improved methods to model the vulnerability of structural systems and nonstructural components to shaking.
  • Earthquake Zone Legend

    FM Global earthquake zones are based on the mean return period of “damaging” ground motions. Shaking is “damaging” when it is strong enough to cause non-trivial damage to structures and contents that are not properly designed to resist earthquake forces. However, the shaking intensity within a zone at that return period could be much higher than this threshold level. FM Global earthquake zones display the mean return period of damaging ground motions at a site, not the mean return period of earthquakes at the site.

    For each FM Global earthquake zone, the following table presents three equivalent ways of conveying the earthquake risk: 1) the mean return period of damaging ground motions; 2) the probability that damaging ground motions will occur in any year i.e., annual probability); and 3) the chance that there will be one or more occurrences of damaging ground motions within a 50-year facility life.

    FM Global Earthquake Zones

    “Damaging” Earthquake Ground Motions

    Zone

    Relative Risk

    Map Legend

    Mean Return Period

    Annual Probability

    Chance of at Least One Occurrence in a 50-Year Facility Life

    50-year

    Severe

    Blue

     

    0 to 50 years

    ≥ 2%

    > 63%

    100-year

    High

    Red

     

    51 to 100 years

    1% to 2%

    39-63%

    250-year

    Moderate

    Orange

     

    101 to 250 years

    0.4% to 1%

    18-39%

    500-year

    Moderate

    Green

     

    251 to 500 years

    0.2% to 0.4%

    10-18%

    >500-year

    Low

    Yellow

     

    >500 years

    < 0.2%

    < 10%

    The mean return period of an event (e.g., damaging ground motion) is the average number of years between successive events. A mean return period of 500 years does not imply that successive events will be exactly 500 years apart. Nor does it imply that there is 100% probability of its occurrence in a 500-year period. This concept can be effectively illustrated by rolling a 6-sided die. There is a one-in-six chance of rolling a “3” (a “return period” of 6); however, in six rolls of the die, it is possible that a “3” will not be rolled and it is also possible that a “3” will be rolled more than once.

    Each FM Global earthquake zone is represented by a single return period of damaging ground motion but encompasses a range of return periods (or annual probabilities), as shown in the table. Earthquake zone boundaries must be drawn somewhere, but it should be recognized that crossing a zone boundary does not necessarily represent a large “jump” in the earthquake risk. If future earthquake zone boundary revisions place a location in a different earthquake zone, this may represent a relatively modest change in the actual risk.

  • Frequently Asked questions


    Q: How is the FM Global earthquake map different from other earthquake maps?

    A: Although the underlying science of the seismic hazard calculations used by building codes and FM Global are largely the same, the two maps include different parameters.

    Building codes map seismic hazards associated with shaking of the underlying bedrock (i.e., based on only the parameters in the first point above). Site condition, and structural and nonstructural vulnerabilities, are accounted for via calculations, not directly in the maps. Building code maps typically display earthquake zones or accelerations in bedrock for a single return period, often 475 or 2475 years. Because the mapped parameter, the return period, and the definition of bedrock can vary from country to country, the bedrock seismic hazard in building code maps is not easily compared worldwide.

    By contrast, FM Global earthquake zones directly display seismic risk, accounting for parameters in all three points above. FM Global zones convey the mean return period of earthquake shaking, including the amplifying effects of local soil, that may cause non-trivial damage to structures if they are not properly designed to resist earthquake forces. Contents and nonstructural components may also be damaged at this level of shaking. FM Global zones are developed using the same methodology worldwide, allowing easy comparison of earthquake risk across the globe.

    Q: How should the FM Global earthquake map be used?

    A: The FM Global earthquake zone indicates a location’s seismic risk. For 50- through 500-year earthquake zone locations, FM Global recommends that their clients implement earthquake design and protection at least as strict as the specifications contained in the FM Global Property Loss Prevention Data Sheets. Several data sheets exclusively address earthquakes:

    • Data Sheet 1-2, Earthquakes
    • Data Sheet 1-11, Fire Following Earthquakes
    • Data Sheet 2-8, Earthquake Protection for Water-Based Fire Protection Systems

    Earthquake protection guidance specific to certain subjects, equipment or occupancies is also contained in other FM Global Property Loss Prevention Data Sheets (e.g., Data Sheet 10-2, Emergency Response and Data Sheet 3-2, Water Tanks for Fire Protection). Register to receive FM Global data sheets at fmglobal.com/datasheets. FM Global recommends that their clients choose products appropriate for use in earthquake zones (e.g., steel suction tanks) or that can be used to provide earthquake protection (e.g., seismic sway brace components for sprinkler piping).

    Earthquake design provisions in the local building code may be more restrictive than those contained in FM Global Property Loss Prevention Data Sheets in certain cases (e.g., local codes may require earthquake design in some FM Global >500-year earthquake zones). Where this occurs, the local building code provisions should be followed.

    Q: How was the FM Global Earthquake map developed?

    A: A team of public, private, academic, and non-governmental organizations worldwide are collaborating to construct a Global Earthquake Model (GEM) ‘mosaic’ hazard model by collating available and newly created regional and national seismic hazard models. FM Global uses the available GEM hazard models and GEM’s OpenQuake software to develop earthquake ground motions in bedrock for multiple return periods for most countries and regions. One exception to this is China, for which a hazard model co-developed by FM Global and the Institute of Geology of the China Earthquake Administration is used.

    Soil amplifications are included in developing FM Global earthquake risk zones, classified using the United States National Earthquake Hazards Reduction Program (NEHRP) soil categories, defined in terms of Vs30 (the average shear wave velocity in the top 30 meters). It is impractical to measure Vs30 at a global scale, so two proxies are used: topographic slope as developed by the United States Geological Survey, and geology (rock or sediment type and age) as developed by the California Geological Survey. These proxies were developed statistically by correlating Vs30 to the proxy parameters in areas where Vs30 data are available. When studies, satellite imagery or historic maps showing local soil conditions in more detail (e.g., areas of reclaimed land or artificial fill) are available, they are used to refine soil classifications.

    The final step in developing FM Global earthquake risk zones is to compare, at each location for each return period, the soil-amplified ground motions with the shaking that may result in significant damage to structural and nonstructural components lacking earthquake protection, from which the final overall zone map can be generated.

  • Excluded Features

    The FM Global earthquake risk zone maps display only the risk due to shaking. Secondary hazards, such as liquefaction, settlement, landslide, fault rupture and tsunami are not considered.

  • Data Sources


    General:

    Allen, T. and Wald, D., 2007. Topographic slope as a proxy for seismic site-condition (Vs30) and amplification around the globe, U.S. Geological Survey, Open File Report 2007-1357.

    FEMA P-1050-1, NEHRP Recommended Seismic Provisions for New Buildings and Other Structures, 2015. Washington, D.C.: Building Seismic Safety Council (BSSC) of the National Institute of Building Sciences (Institute) for the Federal Emergency Management Agency (FEMA) National Earthquake Hazards Reduction Program (NEHRP).

    Wills, C. and Clahan, K., 2006. Developing a map of geologically defined site-condition categories for California, Bulletin of the Seismological Society of America, 96, 1483-1501. doi: 10.1785/0120050179

    Wills, C. and Silva, W., 1998. Shear wave velocity characteristics of geologic units in California, Earthquake Spectra14, 533-556.


    GEM and OpenQuake:

    D’Ayala, D., Meslem, A., Vamvatsikos, D., Porter, K., Rossetto, T., 2015. Guidelines for Analytical Vulnerability Assessment of Low/Mid-Rise Buildings, Global Earthquake Model, Vulnerability Global Component.

    Global Earthquake Model Foundation. [Online]. https://www.globalquakemodel.org/

    Pagani, M., Monelli, D., Weatherill, G., Danciu, L., Crowley, H., Silva, V., Henshaw, P., Butler, L., Nastasi, M., Panzeri, L., Simionato, M. and Vigano, D., 2014. OpenQuake engine: An open hazard (and risk) software for the Global Earthquake Model, Seismological Research Letters 85, 692-702.


    China Earthquake Risk Map:

    Chen, G., Magistrale, H., Rong, Y., Cheng, J., Binselam, S.A. and Xu, X., 2019. Seismic site condition of mainland China from geology. Seismological Research Letters, in revision.

    Cheng, J., Rong, Y., Magistrale, H., Chen, G. and Xu, X., 2017. An Mw-based historical earthquake catalog for mainland China, Bulletin of Seismological Society of America 107, 2490-2500.

    Cheng, J., Rong, Y., Magistrale, H., Chen, G. and Xu, X., 2019. Earthquake rupture scaling relations for mainland China, Seismological Research Letters, submitted.

    Dangkua, D.T., Rong, Y. and Magistrale, H., 2018. Evaluation of NGA‐West2 and Chinese Ground‐Motion Prediction Equations for Developing Seismic Hazard Maps of Mainland China, Bulletin of the Seismological Society of America 108, 2422-2443.

    Rong, Y., Pagani, M., Magistrale, H. and Weatherill, G., 2017. Modeling seismic hazard by integrating historical earthquake, fault, and strain rate data, in The Proceedings of the 16th World Conference on Earthquake Engineering, Santiago, Chile.

    Rong, Y., Shen, Z.-K., Chen, G. and Magistrale, H., 2018. Modeling strain rate and fault slip for China and vicinity using GPS data, Abstract T22A-01, presented at 2018 Fall Meeting, AGU, Washington D. C., 10-14 Dec.

    Rong, Y., Xu, X., Cheng, J., Chen, G. and Magistrale, H., 2019. A probabilistic seismic hazard model for mainland China, Earthquake Spectra, submitted.

About U.S. Hail Map


The contiguous U.S. Hail Map identifies hail hazards based on the frequency and severity of hailstorms. Considering the hail size and frequency together is essential for quantifying the hail hazard, which is the first step toward more cost-effective loss prevention solutions.

The U.S. Hail Map is used to determine the minimum hail ratings recommended by FM Global for above-deck roof components, skylights, heat and smoke vents, metal wall panels and photo-voltaic panels. The hail map is displayed for the contiguous U.S.; the hail hazard for other areas of the world is being determined and additional maps will be released when available.

  • Hail Zone Legend

    Displayed zones are based on a 15-year mean recurrence interval.

    Moderate (Green)

    Location exposed to equivalent hail size ≤ 1.75 in. (44mm)

    Severe (Pink)

    Locations exposed to equivalent hail size > 1.75 in. (44mm) and ≤ 2 in. (51mm)

    Very Severe (Dark Pink)

    Location exposed to equivalent hail size > 2 in. (51mm)

  • Frequently Asked Questions


    Q: What do the hail zones mean?

    A: The hail map characterizes the hail hazard by means of hail zones. The hail zones are defined according to the frequency and severity of the hail hazard, ranging from moderate hail (MH) to severe hail (SH) to very severe hail (VSH). The hail zones are defined as regions where the equivalent hail size ranges between certain damaging hail size thresholds based on a 15-year return period.

    Q: What does equivalent hail size mean?

    A: Hailstones can be spherical, conical or irregular in shape. The size of a hailstone, referred to as its maximum hail size, is typically measured along its maximum dimension. Because hailstones can have various shapes, a unique way of characterizing the size of a hailstone is the equivalent hail size which is the size of a spherical hailstone with the same mass as the irregular-shaped hailstone.

    Q: How should the U.S. Hail Map be used?

    A: The U.S. Hail Map can be used to help determine the minimum hail rating recommended by FM Global for above-deck roof components, skylights, heat and smoke vents, metal wall panels and photo-voltaic panels. It is also used to determine where hail guards for HVAC cooling fins and other equipment should be provided. FM Global offers guidance for hail damage prevention and mitigation in FM Global Property Loss Prevention Data Sheet 1-34, Hail Damage. (Register to receive FM Global data sheets at fmglobal.com/datasheets.) FM Approved roofing products rated for use in Moderate, Severe or Very Severe hail zones can be found in RoofNav (roofnav.com), an online tool that provides the most up-to-date FM Approved roofing products and assemblies.

  • Data Sources

    The hail map is based on data from more than 300,000 hail reports collected throughout the United States since 1955. The hail reports database [1] is hosted by the National Centers for Environmental Information and entered by the National Weather Service (NWS) in accordance with the NWS Directive 10-1605 [2].

    • National Centers for Environmental Information. Storm Events Database. [Online]. https://www.ncdc.noaa.gov/stormevents/

    • National Weather Service, "National Weather Service Instruction 10-1605: Storm Data Preparation," Department of Commerce, National Oceanic and Atmospheric Administration, 2016.