Vegetation

Vegetation patches larger than 1/2 acre. Based on information from reference data sources including 6" resolution aerial photos, Parks and Recreation natural area assessments, and vegetation surveys along the banks of the Willamette and Columbia rivers. Vegetation patches area classified as forest, woodland, shrubland, or herbaceous. The mapping area includes all land within the City of Portland and the unincorporated parts of Multnomah County that are administered by the City of Portland. -- Additional Information: Category: Environmental Purpose: For analyzing vegetation within Portland's riparian and upland areas. Developed as an input to the Bureau of Planning's GIS model for identifying significant natural resources. The key goals of the vegetation mapping project were 1) refine the location of vegetation "patches" of areas previously mapped by Metro; 2) incorporate vegetation maps generated by other agencies such as Portland Parks and Recreation and the Portland Bureau of Environmental Services and refine and improve that information where necessary; 3) map vegetation patches meeting Portland’s criteria for inclusion in the natural resource inventory a 1/2 acre minimum patch size versus the 1 to 2 acre patch size used by Metro for the regional dataset; 4) map all vegetation within a 1/4 mile of a surface stream, wetland, or regionally significant habitat resources included in Metro’s inventory; 5) classify the vegetation into four NVCS classes: forest, woodland, shrubland, and herbaceous; 6) further classify vegetation as either "natural/semi-natural" or "cultivated"; and 7) update, refine and improve the vegetation data annually as new aerial photos become available. Update Frequency: As needed -- Metadata Link: https://www.portlandmaps.com/metadata/index.cfm?&action=DisplayLayer&LayerID=52135本数据集包含面积大于0.5英亩的植被斑块（Vegetation patches）。数据依托以下参考数据源编制：6英寸分辨率航拍照片、公园与休闲管理局自然区域评估报告，以及威拉米特河与哥伦比亚河沿岸的植被调查数据。植被斑块被划分为森林、疏林、灌丛与草本植被四类。制图范围涵盖波特兰市全境，以及由波特兰市管辖的姆尔特诺默县未合并区域。 -- 额外信息： 类别：环境类 用途：用于分析波特兰市河岸带与高地范围内的植被状况。本数据集作为规划局地理信息系统（GIS）模型的输入数据，用于识别区域重要自然资源。 本植被制图项目的核心目标如下： 1. 细化Metro此前已完成制图的植被斑块位置； 2. 整合波特兰公园与休闲管理局、波特兰环境服务局等其他机构制作的植被图件，并在必要时优化完善相关信息； 3. 绘制符合波特兰市自然资源名录纳入标准的植被斑块：要求斑块最小面积为0.5英亩，而Metro在其区域数据集内采用的斑块阈值为1至2英亩； 4. 绘制所有位于地表溪流、湿地或Metro名录收录的区域重要栖息地资源0.25英里范围内的植被； 5. 将植被划分为NVCS四大类别：森林、疏林、灌丛与草本植被； 6. 进一步将植被划分为“自然/半自然”或“人工栽培”两类； 7. 每年在获取新航拍照片后，对植被数据进行更新、优化与完善。 更新频率：按需更新。 元数据链接：https://www.portlandmaps.com/metadata/index.cfm?&action=DisplayLayer&LayerID=52135