Abstract. Climate warming and anthropogenic disturbances result in permafrost degradation in cold regions, including in the Qilian Mountains. These changes lead to extensive hillslope thermokarst (HT) formation, such as retrogressive thaw slumps, active-layer detachment slides, and thermal erosion gullies. These in turn cause, e.g., degradation of local vegetation, economic losses, infrastructure damages, and threats to human safety. However, despite its importance, there is currently no thermokarst inventory for the Qilian Mountains. Through manual visual interpretation and field validation, we therefore produce the first quantification of HT features. We count a total of 1064 HT features, with 67 % located in the upper reaches of the Heihe River basin, which encompasses ∼ 13 % of the Qilian Mountains region. We further identified that 187 HT features (18 %) existed before 2010, while the remaining 874 (82 %) were initiated in the recent period. More specifically, 392 sites (37 %) were initiated during 2010–2015 and 482 (45 %) after 2015. Thermokarst terrain is observed primarily in areas with shallow active-layer depths (average thickness 2.98 m) on northern shaded slopes of 3–25°, with low solar radiation and moderate elevations ranging from 3200 to 4000 m. This first inventory of HT features is an important and missing piece in documenting changes on the Qinghai–Tibetan Plateau, and this new dataset also provides an important basis for further studies, such as automated extraction of HT features, susceptibility analysis of HT, and estimation of losses caused by HT. The datasets are available from the National Tibetan Plateau/Third Pole Environment Data Center and can be downloaded from https://doi.org/10.11888/Cryos.tpdc.300805 (Peng and Yang, 2023).

中文翻译：

---

祁连山多年冻土区首次山坡热岩溶调查

摘要。气候变暖和人为干扰导致包括祁连山在内的寒冷地区的多年冻土退化。这些变化导致了广泛的山坡热岩溶（HT）形成，例如退融滑坡、活动层滑脱滑坡和热侵蚀沟壑。这些反过来又造成当地植被退化、经济损失、基础设施损坏以及对人类安全的威胁等。然而，尽管其重要性，目前还没有祁连山的热岩溶清单。因此，通过手动视觉解释和现场验证，我们首次对 HT 特征进行了量化。我们总共统计了 1064 个 HT 特征，其中 67% 位于黑河流域上游，涵盖了 13% 的祁连山地区。我们进一步确定 187 个 HT 特征 (18%) 在 2010 年之前就已经存在，而其余 874 个 (82%) 是在最近一段时间内启动的。更具体地说，2010-2015 年期间启动了 392 个站点（37%），2015 年之后启动了 482 个站点（45%）。热喀斯特地形主要在活动层深度较浅的地区（平均厚度 2.98 m）、北部阴影坡度为 3-20 米的区域观察到。 25°，太阳辐射低，海拔适中，海拔3200至4000米。首次盘点HT特征是记录青藏高原变化的重要且缺失的部分，这个新数据集也为进一步研究提供了重要基础，例如HT特征的自动提取、HT敏感性分析和估计HT造成的损失。数据集可从国家青藏高原/第三极环境数据中心获取，并可从 https://doi.org/10.11888/Cryos.tpdc.300805 下载（Peng 和 Yang，2023）。