LIDAR Vegetation Object Model (VOM)

The LIDAR derived Vegetation Object Model (VOM) is a raster product produced as part of the Environment Agency’s “Keeping Rivers Cool” project. It is an attempt to identify riparian tree cover and the opportunities for tree planting to increase future shading of streams & rivers. The dataset has been produced by complex GIS modelling of the Environment Agency national LIDAR programme 1m elevation data into discrete objects, with spatial proximity queries against features in Ordnance Survey mapping and Sentinel 2 imagery aiding in the classification of vegetation and non-vegetation objects. The result is a raster product where each pixel represents the height of top of canopy above ground, for all classified vegetation objects above a threshold of 2.5 metres. The data production is fully automated, with no manual QC and editing of the output, other than visual checks. Because of the process to classify objects based on proximity to features within OS mapping there could be some mis-classifications of objects not included in the OS mapping (especially static caravans, shipping containers, large tents / marquees, coastal cliffs and new buildings constructed directly under tree cover). This is a first release of this dataset, the quality of the production methods will be reviewed over the next year, improvements will be made where possible. As there are many potential environmental applications for an open data, national coverage, high resolution Vegetation Object Model the product will be released for all national LIDAR programme survey data captured by the Environment Agency. The Vegetation Object Model is available to download as 5km GeoTiff tiles in the same structure as the other derived products from the national LIDAR programme. Contained within each 5km zip file is the Vegetation Object Model and a hillshade raster produced by adding the VOM onto the Digital Terrain Model. Please refer to the metadata record: https://environment.data.gov.uk/dataset/2e8d0733-4f43-48b4-9e51-631c25d1b0a9 for downloading all other products derived from the national LIDAR programme, including the digital surface and terrain models, intensity rasters or point cloud. Attribution statement: © Environment Agency copyright and/or database right 2022. All rights reserved.激光雷达（LIDAR）衍生植被对象模型（Vegetation Object Model，VOM）是英国环境署（Environment Agency）“维持河道清凉”项目产出的栅格产品，旨在识别河岸林木覆盖情况，并为未来通过植树提升溪流与河道遮阴效果提供可行方案。 本数据集通过复杂的地理信息系统（GIS）建模流程生成：将英国环境署国家激光雷达项目的1米分辨率高程数据转换为离散对象，并结合英国地形测量局（Ordnance Survey）地图要素的空间邻近性查询，以及哨兵2号（Sentinel 2）遥感影像辅助完成植被与非植被对象的分类。 最终产出的栅格产品中，每个像素代表经分类且高度阈值不低于2.5米的植被对象的冠顶离地高度。本数据集的生产流程完全自动化，仅开展视觉核查，未对输出结果进行人工质量控制（QC）与编辑。由于分类流程基于英国地形测量局地图中的要素邻近性，对于未纳入该地图的对象（尤其是固定式旅居房车、集装箱、大型帐篷/临时篷房、海岸悬崖以及直接建于林木覆盖下的新建建筑）可能存在分类错误。本数据集为首次发布，生产方法的质量将在未来一年内接受评估，并视情况开展优化改进。 鉴于高分辨率、全国覆盖的开源植被对象模型具备诸多潜在环境应用场景，本产品将随英国环境署国家激光雷达项目采集的所有勘测数据同步发布。 植被对象模型以5千米见方的GeoTIFF瓦片形式提供下载，其文件结构与国家激光雷达项目的其他衍生产品保持一致。每个5千米压缩包中均包含植被对象模型，以及将VOM叠加至数字地形模型（Digital Terrain Model，DTM）后生成的晕渲栅格图层。 如需下载国家激光雷达项目的其他衍生产品（包括数字表面模型、数字地形模型、强度栅格或点云数据），请查阅元数据记录：https://environment.data.gov.uk/dataset/2e8d0733-4f43-48b4-9e51-631c25d1b0a9。 版权声明：© 英国环境署2022年版权及/或数据库权。保留所有权利。