Ice Wedge Network Centerline and Ice-Wedge Polygon Coverage in the Bernard River Watershed, Banks Island Canada; 2010-2020

Ice-wedge polygon (IWP) is a landform found in landscapes underlain by permafrost. IWPs form due to the development of ice wedges, where each IWP is bounded by ice wedges. Ice wedges form due to repeated cracking of the soil during winter and by snowmelt water infiltrating into the cracks and freezing. Repeated over thousands of years, the process results in ice wedges several 10s of feet deep. The melting of the top of the ice wedge results in ground subsidence and depending how extensive the thaw is across the landscape, new ponds or lateral drainage channels form. This data collection supported an assessment of the length of the ice wedge network in the Barnard River watershed (10,540 km2), Banks Island, Canada. The data collection is derived from the pan-Arctic map of ice-wedge polygons (Witharana et al. 2023, Ice-wedge polygon detection in satellite imagery from pan-Arctic regions, Permafrost Discovery Gateway, 2001-2021. Arctic Data Center. doi:10.18739/A2KW57K57), which used Maxar satellite imagery from 2010-2020 for Banks Island. Two types of datasets are included: (1) Polyline shapefile of mapped ice wedge centerlines. This dataset was produced with an approach adopted from Ulrich, Mathias, et al. "Quantifying wedge‐ice volumes in Yedoma and thermokarst basin deposits." Permafrost and Periglacial Processes 25.3 (2014): 151-161. A buffer that represents widths at the top of ice wedges is created around each IWP. A buffer width of 5 meters was chosen, since this allowed buffers of adjacent polygons to overlap. These buffers are then skeletonized in order to trace their centerlines, which ultimately represents the network of ice-wedges that form the IWPs in a landscape. (2) Polygon shapefile of IWP coverage (as percentage of land cover within 1 kilometer (km) x 1 km rectangular grid cells) across the 10,540 km2 Bernard River Watershed, Banks Island, Canada. Code for ice-wedge centerline extraction can be found at https://github.com/PermafrostDiscoveryGateway/IW-Network-Extraction. This data collection accompanies the manuscript published in Nature Water (Liljedahl, A.K., Witharana, C., and Manos, E., 2024. The Capillaries of the Arctic Tundra. Nature Water, doi:10.1038/s44221-024-00276-9) and the geospatial data is available to view in the Permafrost Discovery Gateway.冰楔多边形（Ice-wedge polygon, IWP）是发育在永久冻土（permafrost）覆盖区域的典型地貌形态。IWP由冰楔作用形成，其边界由冰楔构成。冰楔的形成源于冬季土壤反复开裂，融雪水渗入裂缝并冻结；历经数千年的重复过程，最终可形成数十英尺深的冰楔。冰楔顶部融化会引发地面沉降，根据区域内融冻作用的规模，可形成新的水塘或侧向排水通道。 本数据集用于评估加拿大班克斯岛巴纳德河流域（面积10540 km²）内的冰楔网络长度。数据集源自泛北极冰楔多边形地图（Witharana等，2023，《泛北极区域卫星影像中的冰楔多边形检测》，永久冻土发现网关，2001-2021。北极数据中心，doi:10.18739/A2KW57K57），该地图使用2010-2020年的Maxar卫星影像对班克斯岛完成制图。 数据集包含两类数据： 1. 冰楔中心线折线矢量shapefile：本数据集采用Ulrich等提出的方法生成，原文参考：Ulrich, Mathias, et al. "Quantifying wedge‐ice volumes in Yedoma and thermokarst basin deposits." Permafrost and Periglacial Processes 25.3 (2014): 151-161。首先为每个IWP创建代表冰楔顶部宽度的缓冲区，最终选定5米作为缓冲区宽度，该设置可使相邻多边形的缓冲区产生重叠。随后对这些缓冲区进行骨架化处理，以追踪其中心线，最终得到构成区域内IWP的冰楔网络。 2. IWP覆盖范围多边形矢量shapefile：以1千米×1千米的矩形网格为统计单元，计算每个网格内冰楔多边形的土地覆盖占比，覆盖范围为加拿大班克斯岛巴纳德河流域（10540 km²）。 冰楔中心线提取代码可在https://github.com/PermafrostDiscoveryGateway/IW-Network-Extraction获取。本数据集配套发表于《自然·水》（Nature Water）的论文（Liljedahl, A.K., Witharana, C., and Manos, E., 2024. "The Capillaries of the Arctic Tundra." Nature Water, doi:10.1038/s44221-024-00276-9），其地理空间数据可在永久冻土发现网关中查看。