FWS National Realty Boundaries

These boundaries are simplified from the U.S. Fish and Wildlife Service Real Estate Interest data layer containing polygons representing tracts of land (parcels) in which the Service has a real estate interest. Interior boundaries between parcels were dissolved to produce a single set of simplified external boundaries for each feature. These are resource grade mapping representations of the U.S. Fish and Wildlife Service boundaries. For legal descriptions of the land represented here, contact the USFWS Realty Office. This map layer was compiled by the U.S. Fish and Wildlife Service. Although these boundaries represent lands administered by the U.S. Fish and Wildlife Service, not all areas are open to the public. Some fragile habitats need to be protected from human traffic and some management areas are closed. The public is urged to contact specific Refuges or other conservation areas before visiting. Data can also be downloaded from ServCat, the FWS Catalog. Go to this link for downloadable cadastral data: https://iris.fws.gov/APPS/ServCat/SavedSearch/Profile/2674 This dataset contains features which have been modified from the source regional data. For select features, geometry has been generalized up to a specified threshold to reduce a high number of vertices in large multipart polygons and improve web service performance. Currently five or fewer features are generalized in each dataset, with the generalization tolerance varying from 1m up to 30m per feature, as required. To further improve web service performance: OGC geometry problems were automatically fixed where possible, true curves were densified, and the data were projected into the WGS 1984 Web Mercator Auxiliary Sphere projection. Sync is enabled, but editing is disabled. POC for these data are: [e-mail]

本数据集的边界源自美国鱼类及野生动物管理局（U.S. Fish and Wildlife Service, USFWS）的不动产权益数据图层，该图层包含代表该局享有不动产权益的土地片区（地块，parcels）的多边形要素。已将地块间的内部边界进行融合处理，为每个要素生成一套简化后的外部边界集合。本数据集为美国鱼类及野生动物管理局边界的资源级制图成果。若需获取本数据集所代表土地的法律权属描述，请联系USFWS不动产办公室。
本地图图层由美国鱼类及野生动物管理局编制。尽管本数据集的边界所代表的土地由该局管理，但并非所有区域均对公众开放。部分脆弱栖息地需避免人类活动干扰，部分管理区域处于封闭状态。特此提醒公众在到访前，请先联系具体的野生动物庇护所或其他保护区域。
数据亦可从ServCat（美国鱼类及野生动物管理局目录）下载。可通过以下链接获取可下载的地籍数据：https://iris.fws.gov/APPS/ServCat/SavedSearch/Profile/2674
本数据集包含源自原始区域数据并经过修改的地理要素。针对部分选定的地理要素，已按照指定阈值对其几何形状进行泛化处理，以减少大型多部件多边形中过多的顶点数量，提升Web服务性能。当前每个数据集中仅会对不超过5个地理要素进行泛化处理，且根据实际需求，每个要素的泛化容差范围为1米至30米不等。
为进一步提升Web服务性能，已在可行范围内自动修复开放地理空间联盟（OGC, Open Geospatial Consortium）几何格式问题，对真实曲线进行节点加密，并将数据投影至WGS 1984 Web墨卡托辅助球体投影坐标系。本数据集已启用数据同步功能，但禁用编辑功能。本数据的联络人邮箱为：[e-mail]