National Flood Hazard Layer - Pike County 2000

The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters Of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. The specification for the horizontal control of FIRM Databases is consistent with those required for mapping at a scale of 1:12,000. This file is georeferenced to the Earth's surface using the Geographic Coordinate System (GCS) and North American Dataum of 1983 (NSRS-2007). This data is hosted at, and may be downloaded or accessed from PASDA, the Pennsylvania Spatial Data Access Geospatial Data Clearinghouse http://www.pasda.psu.edu/uci/DataSummary.aspx?dataset=2295国家洪水灾害图层（National Flood Hazard Layer, NFHL）数据整合了联邦紧急事务管理署（Federal Emergency Management Agency, FEMA）发布的所有洪水保险费率图（Flood Insurance Rate Map, FIRM）数据库，以及自该数据库发布之日起针对该数据库出具的所有地图修订函（Letters Of Map Revision, LOMRs）。该数据每月更新一次。洪水保险费率图数据库是已发布纸质洪水保险费率图所承载的洪水灾害信息的数字化地理空间版本。该数据库描绘了用于生成风险数据的洪水风险信息及配套支撑数据。其采用的核心风险分类包括年发生概率为1%的洪水事件、年发生概率为0.2%的洪水事件，以及最低洪水风险区域。洪水保险费率图数据库源自洪水保险研究（Flood Insurance Studies, FISs）、此前发布的洪水保险费率图、为支撑洪水保险研究与洪水保险费率图开展的洪水灾害分析，以及现有可用的新制图数据。上述洪水保险研究与洪水保险费率图均由联邦紧急事务管理署发布。国家洪水灾害图层可按州或美国领地数据集形式提供。每个州或领地数据集包含该数据集发布当日可用的全部洪水保险费率图数据库及对应的地图修订函。洪水保险费率图数据库的水平控制规范与1:12000比例尺制图的要求一致。该文件采用地理坐标系（Geographic Coordinate System, GCS）及北美1983大地基准（North American Datum of 1983, NSRS-2007）完成地球表面地理配准。 本数据托管于宾夕法尼亚空间数据访问地理空间数据交换中心（Pennsylvania Spatial Data Access Geospatial Data Clearinghouse, PASDA），可通过以下网址下载或访问：http://www.pasda.psu.edu/uci/DataSummary.aspx?dataset=2295。