Canopy Height Map of Los Angeles County Native Habitat Areas

Using LARIAC4 (2016) LIDAR imagery this Canopy Height Model was derived using the lidR, terra and sf packages in R at a resolution of 1 meter. Native habitat areas were selected based on occurence of native flora taxa from iNaturalist in each LARIAC tile. Tiles with no or very few native plants were not included. Additionally, LA County north of the Santa Clara river and San Gabriel mountains was not included, please contact me if you need additional areas. Non-organic features such as power lines, houses, and some high altitude LIDAR noise are still present in the data, future efforts are needed to remove these. Processing took place on the Occidental College computing cluster using a machine with 192GB RAM and 32 cores and took approximately 3 days. The code used to generate this CHM is available here: https://gist.github.com/max-mapper/d52ad9df2f9ed4d191e67955f950e044. The CHM is available as Cloud Optimized Geotiff, which can be viewed in QGIS dynamically over HTTPS without requiring a full download.本研究基于LARIAC4 (2016)激光雷达（LiDAR）影像，依托R语言的lidR、terra及sf软件包，以1米的空间分辨率生成冠层高度模型（Canopy Height Model, CHM）。原生栖息地区域的筛选以各LARIAC分幅影像中iNaturalist平台记录的本土植物类群分布为依据，无本土植物或本土植物丰度极低的分幅未被纳入数据集。此外，圣克拉拉河以北及圣盖博山脉范围内的洛杉矶县区域未被纳入数据集；若需获取额外区域的数据，请联系作者。数据中仍存在非自然地物（如输电线路、房屋）及部分高空激光雷达噪点，后续仍需开展处理工作以移除此类干扰。本数据集的处理依托西方学院（Occidental College）计算集群完成，所用计算节点配备192GB内存与32核心处理器，整体处理耗时约3天。用于生成该冠层高度模型的代码可通过以下链接获取：https://gist.github.com/max-mapper/d52ad9df2f9ed4d191e67955f950e044。本冠层高度模型以云优化GeoTIFF（Cloud Optimized Geotiff, COG）格式提供，可通过HTTPS协议在QGIS中动态加载预览，无需完整下载整个数据集。