Earthquake Risk Index Rating, County, National Risk Index

National Risk Index Data Version: December 2025 (1.20.0) An earthquake is a shaking of the earth's surface by energy waves emitted by slowly moving tectonic plates overcoming friction with one another underneath the earth's surface. The Earthquake Risk Index Rating, County, National Risk Index view feature layer contains Risk Index data for earthquake at the county level. The National Risk Index data helps to illustrate the communities most at risk for 18 natural hazards across the United States and territories: avalanche, coastal flooding, cold wave, drought, earthquake, hail, heat wave, hurricane, ice storm, inland flooding, landslide, lightning, strong wind, tornado, tsunami, volcanic activity, wildfire, and winter weather. The National Risk Index data provides Risk Index values, scores and ratings based on data for Expected Annual Loss due to natural hazards, Social Vulnerability, and Community Resilience. Separate values, scores and ratings are also provided for Expected Annual Loss, Social Vulnerability, and Community Resilience. For the Risk Index and Expected Annual Loss, values, scores and ratings can be viewed as a composite score for all hazards or individually for each of the 18 hazard types. Sources for Expected Annual Loss data include: Arizona State University’s Center for Emergency Management and Homeland Security California Department of Conservation – Geological Survey Colorado Avalanche Information Center Snow Data Assimilation System National Water and Climate Center Snow Survey and Water Supply Forecasting Program Snow Telemetry Network Northern Hemisphere 0.25 Degree Resolution Machine Learning Snow Depth Data CoreLogic’s Flood Services Federal Emergency Management Agency National Flood Insurance Program FEMA Natural Hazards Risk Assessment Program Humanitarian Data Exchange Iowa State University's Iowa Environmental Mesonet Multi-Resolution Land Characteristics Consortium National Earthquake Hazards Reduction Program National Oceanic and Atmospheric Administration’s National Centers for Environmental Information National Oceanic and Atmospheric Administration's National Hurricane Center National Oceanic and Atmospheric Administration's National Weather Service National Oceanic and Atmospheric Administration's Office for Coastal Management National Oceanic and Atmospheric Administration's National Geophysical Data Center National Oceanic and Atmospheric Administration's Storm Prediction Center U.S. Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory U.S. Census Bureau U.S. Department of Agriculture's National Agricultural Statistics Service U.S. Forest Service's Fire Modeling Institute's Missoula Fire Sciences Lab U.S. Geological Survey U.S. Geological Survey's Landslide Hazards Program U.S. Geological Survey Western Geographic Science Center Hazard Vulnerability Team United Nations Office for Disaster Risk Reduction University of Alaska – Fairbanks' Alaska Earthquake Center University of Nebraska – Lincoln's National Drought Mitigation Center Data for Social Vulnerability are provided by the U.S. Census Community Resilience Estimate, and data for Community Resilience are obtained from the University of South Carolina's Hazards and Vulnerability Research Institute’s 2020 Baseline Resilience Indicators for Communities. These obtained data were used to create a FEMA modified version of the Baseline Resilience Indicators for Communities for use in the National Risk Index dataset. The source of the boundaries for counties and Census tracts are based on the U.S. Census Bureau’s 2021 TIGER/Line shapefiles, except for Connecticut which uses the 2024 TIGER/Line shapefiles. Building value and population exposures for communities are based on FEMA’s Hazus 6.0 and inflation adjusted to December 2024 dollars. Agriculture values are based on the U.S. Department of Agriculture 2017 Census of Agriculture and inflation adjusted to December 2024 dollars. National Risk Index Dataset - Metadata National Risk Index Dataset - Data Dictionary National Risk Index Dataset - Data Glossary National Risk Index Dataset - Technical Documentation国家风险指数（National Risk Index）数据集 版本：2025年12月（1.20.0）。地震是指地球内部缓慢移动的板块克服相互间摩擦力并释放能量波，进而引发的地表震动现象。县级地震风险指数评级视图要素图层（Earthquake Risk Index Rating, County, National Risk Index view feature layer）包含县级尺度的地震风险指数数据。国家风险指数数据集可用于展示美国及所辖领土内18种自然灾害中受风险威胁最突出的社区，涵盖雪崩、沿海洪水、寒潮、干旱、地震、冰雹、热浪、飓风、冰暴、内陆洪水、滑坡、雷击、强风、龙卷风、海啸、火山活动、野火以及冬季天气。该数据集基于自然灾害预期年度损失、社会脆弱性（Social Vulnerability）和社区韧性（Community Resilience）三类核心数据，生成风险指数数值、得分与评级。同时也分别提供了预期年度损失、社会脆弱性和社区韧性的单独数值、得分与评级。针对风险指数与预期年度损失，既可查看全灾害综合评分，也可查看18种灾害类型各自的分项评分。预期年度损失数据的来源包括：亚利桑那州立大学应急管理与国土安全中心、加利福尼亚州保护部地质调查局、科罗拉多雪崩信息中心、雪数据同化系统、国家水与气候中心雪调查与供水预报项目、雪遥测网络、北半球0.25度分辨率机器学习雪深数据、CoreLogic洪水服务部门、联邦紧急事务管理局（Federal Emergency Management Agency）国家洪水保险计划、联邦紧急事务管理局（FEMA）自然灾害风险评估项目、人道主义数据交换平台、艾奥瓦州立大学艾奥瓦环境气象网、多分辨率土地特征联盟、国家地震灾害减轻计划、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration）国家环境信息中心、美国国家海洋和大气管理局国家飓风中心、美国国家海洋和大气管理局国家气象局、美国国家海洋和大气管理局海岸管理办公室、美国国家海洋和大气管理局国家地球物理数据中心、美国国家海洋和大气管理局风暴预测中心、美国陆军工程兵团寒区研究与工程实验室、美国人口普查局、美国农业部国家农业统计服务处、美国林务局火灾建模研究所密苏拉火灾科学实验室、美国地质调查局（U.S. Geological Survey）、美国地质调查局滑坡灾害项目、美国地质调查局西部地理科学中心灾害脆弱性团队、联合国减灾办公室、阿拉斯加大学费尔班克斯分校阿拉斯加地震中心、内布拉斯加大学林肯分校国家干旱缓解中心。社会脆弱性数据由美国人口普查局提供。社区韧性数据源自南卡罗来纳大学灾害与脆弱性研究所2020年版《社区韧性基准指标》。本数据集采用了联邦紧急事务管理局对该基准指标的修改版本。县级及普查分区（Census tracts）的边界数据基于美国人口普查局2021年TIGER/Line形状文件，康涅狄格州除外，其采用2024年TIGER/Line形状文件。社区的建筑价值与人口暴露数据基于FEMA的Hazus 6.0模型，并已按2024年12月美元价值进行通胀调整。农业价值数据基于美国农业部2017年农业普查结果，并已按2024年12月美元价值进行通胀调整。国家风险指数数据集附带以下配套资料：数据集元数据、数据字典、数据术语表以及技术文档。