Abstract. Quantifying the extent and distribution of supraglacial hydrology, i.e. lakes and streams, is important for understanding the mass balance of the Antarctic ice sheet, and its consequent contribution to global sea level rise. The existence of meltwater on the ice surface has the potential to affect ice shelf stability and grounded ice flow, through hydrofracturing and the associated delivery of meltwater to the bed. In this study, we systematically map all observable supraglacial lakes and streams in West Antarctica, by applying a semi-automated Dual-NDWI (Normalised Difference Water Index) approach to > 2000 images acquired by the Sentinel-2 and Landsat-8 satellites during January 2017. We use a K-Means clustering method to partition water into lakes and streams, which is important for understanding the dynamics and inter-connectivity of the hydrological system. When compared to a manually-delineated reference dataset on three Antarctic test sites, our approach achieves average values for sensitivity (85.3 % and 77.6 %), specificity (99.1 % and 99.7 %) and accuracy (98.7 % and 98.3 %) for Sentinel-2 and Landsat-8 acquisitions, respectively. In total, we identified 10,478 supraglacial features (10,223 lakes and 255 channels) on the West Antarctic Ice Sheet (WAIS) and Antarctic Peninsula (AP), with a combined area of 119.4 km² (114.7 km² lakes, 4.7 km² channels). 27.3 % of feature area was found on grounded ice, 17.8 % of feature area comprised lakes which crossed the grounding line, while 54.9 % of feature area was found on floating ice shelves. New continental-scale inventories such as these, the first produced for WAIS and AP, are made possible by the recent expansion in satellite data provision. The inventories provide a baseline for future studies and a benchmark to monitor the development of Antarctica’s surface hydrology in a warming world, and thus enhance our capability to predict the collapse of ice shelves in the future. The dataset is available at https://doi.org/10.5281/zenodo.5109856 (Corr et al., 2021).



中文翻译：

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南极西部冰盖上的冰上湖泊和河道清单

摘要。量化冰上水文（即湖泊和溪流）的范围和分布对于了解南极冰盖的质量平衡及其对全球海平面上升的影响非常重要。冰面上融水的存在有可能通过水力压裂和相关的融水输送到冰床而影响冰架稳定性和接地冰流。在这项研究中，我们通过对 Sentinel-2 和 Landsat-8 卫星在 1 月份获取的 > 2000 幅图像应用半自动双 NDWI（标准化差分水指数）方法，系统地绘制了南极洲西部所有可观测的冰上湖泊和溪流2017. 我们使用 K-Means 聚类方法将水划分为湖泊和溪流，这对于理解水文系统的动态和相互联系很重要。与三个南极测试站点上手动描绘的参考数据集相比，我们的方法实现了 Sentinel-的灵敏度（85.3% 和 77.6%）、特异性（99.1% 和 99.7%）和准确度（98.7% 和 98.3%）的平均值。 2 和 Landsat-8 的收购，分别。我们在南极西部冰盖 (WAIS) 和南极半岛 (AP) 总共确定了 10,478 个冰上特征（10,223 个湖泊和 255 个通道），总面积为 119.4 平方公里 分别。我们在南极西部冰盖 (WAIS) 和南极半岛 (AP) 总共确定了 10,478 个冰上特征（10,223 个湖泊和 255 个通道），总面积为 119.4 平方公里 分别。我们在南极西部冰盖 (WAIS) 和南极半岛 (AP) 总共确定了 10,478 个冰上特征（10,223 个湖泊和 255 个通道），总面积为 119.4 平方公里^{2 个}（114.7 公里^{2 个}湖泊，4.7 公里^{2 个}渠道）。27.3% 的特征区域位于接地冰上，17.8% 的特征区域由跨越接地线的湖泊组成，而 54.9% 的特征区域位于浮冰架上。最近卫星数据提供的扩展使诸如此类的新大陆规模清单成为可能，这些清单最初是为 WAIS 和 AP 制作的。这些清单为未来的研究提供了基准，也为监测南极洲表面水文在变暖世界中的发展提供了基准，从而增强了我们预测未来冰架崩塌的能力。该数据集可在 https://doi.org/10.5281/zenodo.5109856（Corr 等人，2021 年）获得。