Mapped drainage ditches in forested landscapes

This data contains 1607 km of manually digitized ditch channels from Sweden and high-resolution digital elevation models for the same areas. The data was digitized in 10 regions that were dominated by forests. Each region was selected to achieve a good representation of different landscape properties concerning topography, soil conditions, runoff, land use, and tree species. A compact laser-based system (Leica ALS80-HP-8236) was used to collect LiDAR data from an aircraft flying at 2888 -3000 m. The ALS point clouds have a last and only return density of 1-2 points m-2 and were divided into 55 tiles with the size of 2.5 x 2.5 km each and covering a total of 344 km2. DEMs with 0.5 m resolution were created from the LiDAR point clouds using a tin gridding approach implemented in Whitebox tools 1.4.0 (https://github.com/jblindsay/whitebox-tools).

The data were digitized in a collaboration between the Swedish university of agricultural sciences: https://www.slu.se/ and the Swedish Forest Agency: https://www.skogsstyrelsen.se/
ditchlines.zip contains vector lines of the digitized ditch channels.
vectorfiles.zip contains polygons where the ditches were digitized and the extent of the raster tiles.
rastertiles.zip contains raster tiles with a resolution of 0.5 m covering the same areas.

本数据集包含瑞典境内1607千米的人工数字化沟渠河道数据，以及对应区域的高分辨率数字高程模型（digital elevation model, DEM）。数据采集自10个以森林为主的研究区域，每个区域的选取均充分兼顾了地形、土壤条件、径流、土地利用及树种等多类景观属性的代表性。
研究采用紧凑型激光扫描系统（Leica ALS80-HP-8236），在飞行高度为2888至3000米的航空器上采集激光雷达（Light Detection and Ranging, LiDAR）数据。该机载激光雷达点云仅包含最后一次回波，点密度为1~2点/平方米，被划分为55个尺寸为2.5×2.5千米的瓦片，总覆盖面积达344平方千米。研究人员采用Whitebox Tools 1.4.0软件中实现的不规则三角网（Triangulated Irregular Network, TIN）网格化方法，从激光雷达点云中生成了分辨率为0.5米的数字高程模型，相关工具的开源地址为：https://github.com/jblindsay/whitebox-tools。

本数据集由瑞典农业科学大学（Swedish University of Agricultural Sciences, SLU，官方网址：https://www.slu.se/）与瑞典森林局（Swedish Forest Agency，官方网址：https://www.skogsstyrelsen.se/）合作完成数字化工作。

ditchlines.zip 内含数字化沟渠河道的矢量线要素；vectorfiles.zip 内含沟渠数字化区域的多边形数据及栅格瓦片的范围信息；rastertiles.zip 内含覆盖对应研究区域、分辨率为0.5米的栅格瓦片数据。