FEMA LOMAs

This feature layer contains point locations of FEMA Letters of Map Amendment (LOMAs) within Montgomery County, Texas. Each point generally represents an address or property for which FEMA has issued an official LOMA, amending the effective Flood Insurance Rate Map (FIRM) to reflect that the property or structure is not located in the mapped Special Flood Hazard Area (SFHA). LOMAs are issued when property owners or their representatives provide technical data (such as certified elevation information) demonstrating that the property is on naturally high ground above the Base Flood Elevation (BFE), and has been inadvertently mapped in the SFHA. The layer was created from FEMA LOMA data and includes one point for each geocoded or otherwise spatially located LOMA record. Attributes typically include a case or determination number, address or parcel identifier, community information, effective date, and basic determination details, depending on the fields available from the source data. This layer is intended to provide a mapped view of where LOMAs have been issued, supporting local floodplain management, planning, and outreach activities when used in combination with FEMA flood hazard layers and local data. Important considerations for use: Point locations may be approximate, depending on how the original address or location description was converted to coordinates. The dataset typically includes only LOMAs that have associated coordinates; some LOMAs may exist in FEMA’s records but not appear in this map if no coordinate was available at the time of processing. A LOMA determination applies specifically to the property/structure described in the FEMA letter and does not automatically extend to neighboring properties.本要素图层包含美国得克萨斯州蒙哥马利县范围内的联邦紧急事务管理局（Federal Emergency Management Agency, FEMA）地图修订函（Letters of Map Amendment, LOMAs）的点位信息。每个点位通常对应一处由FEMA核发官方LOMA的地址或房产，该函件用于修订生效的洪水保险费率图（Flood Insurance Rate Map, FIRM），以明确该房产或建筑不在划定的特殊洪水危险区（Special Flood Hazard Area, SFHA）范围内。当房产所有人或其代理人提交技术资料（如经认证的高程信息），证明该房产坐落于基准洪水高程（Base Flood Elevation, BFE）以上的自然高地上，且被误划入特殊洪水危险区时，FEMA便会核发LOMA。本图层基于FEMA的LOMA原始数据构建，每个点位对应一条经过地理编码或其他空间定位的LOMA记录。其属性字段通常涵盖案件/判定编号、地址或地块标识符、社区信息、生效日期以及基本判定详情，具体字段取决于源数据的可用内容。本图层旨在直观呈现已核发LOMAs的空间分布，配合FEMA洪水灾害图层及本地数据使用时，可辅助开展本地洪水泛区管理、规划及宣传推广等工作。使用本图层时需注意以下事项：点位坐标可能存在近似偏差，具体误差取决于原始地址或位置描述转换为坐标的方式；本数据集通常仅收录带有配套坐标的LOMA记录，部分虽收录于FEMA档案但处理时未获取坐标的LOMA，将不会出现在本图层中；LOMA判定仅适用于该函件中描述的房产或建筑，不会自动延伸至相邻地块。