ss2.climatecentral.orgSurging Seas: Risk Zone Map

× You are using an unsupported browser. PleaseCDKN is a programme funded by DFID and the Netherlands Directorate-General for International Cooperation (DGIS) for the benefit of developing countries. To NOAA’s Office for Coastal Management , which has provided high-accuracy coastal elevation data, consistent courtesy, and leadership with its Sea Level Rise Viewer , a map tool Surging Seas strives to complement. To our project partner for U.S. social vulnerability analysis, the University of South Carolina Hazards and Vulnerability Research Institute .Site Credits Map designed and built in collaboration with Stamen Design in San Francisco. Icons (U.S.) Hospital icon used to represent Hospitals designed by Saman Bemel-Benrud from The Noun Project. Badge icon used to represent Fire/EMS/Police stations designed by Edward Boatman from The Noun Project. School icon used to represent Schools/Colleges designed by Saman Bemel-Benrud from The Noun Project. Prayer icon used to represent Houses of Worship was designed by Carson Wittenberg from The Noun Project. Museum icon used to represent Culture/Museums/Arts designed by Unknown Designer from The Noun Project. Government Office icon used to represent Government/Community designed by OCHA AVMU from The Noun Project. Power Plant icon used to represent Powerplants designed by Iconathon with Collaboration by Chad Williamsen, Katie Williamsen, Alison Harshbarger & John Durkee from The Noun Project. Caution icon used to represent EPA-Listed Sites designed by Sam Ahmed from The Noun Project.General Disclaimer & Legal Terms The purpose of our web tools is to provide local regions and policy makers with the tailored local information they need to understand and respond to the risks of sea level rise and coastal flooding. Our web tools are screening/scoping tools that use consistent data sets and analyses at the national level within the U.S., and a different consistent set across all other nations outside the U.S. For information visit Disclaimer | Terms of Use Help | Contact | Disclaimer | Terms of Use | PrivacyAbout This Site × Introduction | Methods and Qualifiers | Data Layers | Sources | Services | Team | Special Thanks | Site Credits | Legal Introduction Climate Central’s Surging Seas: Risk Zone map shows areas vulnerable to near-term flooding from different combinations of sea level rise, storm surge, tides, and tsunamis, or to permanent submersion by long-term sea level rise. Within the U.S., it incorporates the latest, high-resolution, high-accuracy lidar elevation data supplied by NOAA (exceptions: see Sources ), displays points of interest, and contains layers displaying social vulnerability, population density, and property value. Outside the U.S., it utilizes satellite-based elevation data from NASA. It provides the ability to search by location name or postal code. The accompanying Risk Finder is an interactive data toolkit available for some countries that provides local projections and assessments of exposure to sea level rise and coastal flooding tabulated for many sub-national districts, down to cities and postal codes in the U.S. Exposure assessments always include land and population, and in the U.S. extend to over 100 demographic, economic, infrastructure and environmental variables using data drawn mainly from federal sources, including NOAA, USGS, FEMA, DOT, DOE, DOI, EPA, FCC and the Census. This web tool was highlighted at the launch of The White House’s Climate Data Initiative in March 2014. Climate Central’s original Surging Seas was featured on NBC , CBS , and PBS U.S. national news, the cover of The New York Times , in hundreds of other stories, and in testimony for the U.S. Senate . The Atlantic Cities named it the most important map of 2012 . Both the Risk Zone map and the Risk Finder are grounded in peer-reviewed science .Methods and Qualifiers This map is based on analysis of digital elevation models mosaicked together for near-total coverage of the global coast. Details and sources for U.S. and international data are below. Elevations are transformed so they are expressed relative to local high tide lines (Mean Higher High Water, or MHHW). A simple elevation threshold-based bathtub method” is then applied to determine areas below different water levels, relative to MHHW. Within the U.S., areas below the selected water level but apparently not connected to the ocean at that level are shown in a stippled green (as opposed to solid blue) on the map. Outside the U.S., due to data quality issues and data limitations, all areas below the selected level are shown as solid blue, unless separated from the ocean by a ridge at least 20 meters (66 feet) above MHHW, in which case they are shown as not affected (no blue). Elevation (U.S.) Elevation data used for parts of this map within the U.S. come almost entirely from ~5-meter horizontal resolution digital elevation models curated and distributed by NOAA in its Coastal Lidar collection, derived from high-accuracy laser-rangefinding measurements. The same data are used in NOAA’s Sea Level Rise Viewer . (High-resolution elevation data for Louisiana, southeast Virginia, and limited other areas comes from the U.S. Geological Survey (USGS) ). Elevation Warnings (Global and Alaska) Areas of this map outside the U.S. use elevation data on a roughly 90-meter horizontal resolution grid derived from NASA’s Shuttle Radar Topography Mission (SRTM). SRTM provides surface elevations, not bare earth elevations, causing it to commonly overestimate elevations, especially in areas with dense and tall buildings or vegetation. Therefore, the map under-portrays areas that could be submerged at each water level, and exposure is greater than shown (Kulp and Strauss, 2016) . However, SRTM includes error in both directions, so some areas showing exposure may not be at risk. SRTM data do not cover latitudes farther north than 60 degrees or farther south than 56 degrees, meaning that sparsely populated parts of Arctic Circle nations are not mapped here, and may show visual artifacts. Areas of this map in Alaska use elevation data on a roughly 60-meter horizontal resolution grid supplied by the U.S. Geological Survey (USGS) . This data is referenced to a vertical reference frame from 1929, based on historic sea levels, and with no established conversion to modern reference frames. The data also do not take into account subsequent land uplift and subsidence, widespread in the state. As a consequence, low confidence should be placed in Alaska map portions. Flood control structures (U.S.) Levees, walls, dams or other features may protect some areas, especially at lower elevations. Levees and other flood control structures are included in this map within but not outside of the U.S., due to poor and missing data. Within the U.S., data limitations, such as an incomplete inventory of levees, and a lack of levee height data, still make assessing protection difficult. For this map, levees are assumed high and strong enough for flood protection. However, it is important to note that only 8% of monitored levees in the U.S. are rated in Acceptable” condition (ASCE). Also note that the map implicitly includes unmapped levees and their heights, if broad enough to be effectively captured directly by the elevation data. For more information on how Surging Seas incorporates levees and elevation data in Louisiana, view our Louisiana levees and DEMs methods PDF . For more information on how Surging Seas incorporates dams in Massachusetts, view the Surging Seas column of the web tools comparison matrix for Massachusetts . Error Errors or omissions in elevation or levee data may lead to areas being misclassified. Furthermore, this analysis does not account for future erosion, marsh migration, or construction. As is general best practice, local detail should be verified with a site visit. Sites located in zones below a given water level may or may not be subject to flooding at that...