Floodplains (FEMA, DFIRM 2011) (File Geodatabase)

The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop 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 DFIRM Database is derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (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 the Federal Emergency Management Agency (FEMA). The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The DFIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The DFIRM database is a subset of the Digital FIS database that serves to archive the information collected during the FIS. For more information, contact: GIS Manager Information Technology & Innovation (ITI) Montgomery County Planning Department, MNCPPC T: 301-650-5620数字洪水保险费率地图（Digital Flood Insurance Rate Map, DFIRM）数据库呈现了用于研发风险数据的洪水风险信息与配套支撑数据集。该数据库采用的核心风险分类包括年度发生概率1%的洪水事件、年度发生概率0.2%的洪水事件以及最低洪水风险区域。DFIRM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地图（Flood Insurance Rate Maps, FIRMs）、为支撑FIS与FIRM编制所开展的洪水灾害分析，以及可获取的新型测绘数据。上述FIS与FIRM均由联邦紧急事务管理局（Federal Emergency Management Agency, FEMA）发布。FIRM是国家洪水保险计划（National Flood Insurance Program, NFIP）项下洪泛区管理、灾害减缓及保险业务的核心依据。其保险应用场景包括执行《洪水灾害保护法》规定的强制投保要求，该法第2(b)(4)条明确要求：“对于在已识别的特殊洪水危险区域内或拟在此类区域内购置、改造土地设施的物业所有者，若其获得联邦项目援助，或由联邦监管、规范或承保的机构或单位提供相关协助，则必须购买洪水保险。”该条款出自1973年《洪水灾害保护法》。除识别特殊洪水危险区（Special Flood Hazard Areas, SFHAs）外，FIRM上标注的风险分区也是NFIP项下洪水保险保费费率制定的核心依据。DFIRM数据库以适配电子测绘应用的数字化格式，呈现了FIRM中所载的洪水风险信息。DFIRM数据库是数字FIS数据库的子集，用于归档FIS编制过程中收集的相关信息。如需更多信息，请联系：蒙哥马利县规划部信息技术与创新（Information Technology & Innovation, ITI）部门地理信息系统管理员，MNCPPC，电话：301-650-5620