Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of Central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62000 km2. Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and GRACE satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68-0.7), and number of thawing days (i.e., a number of days with tmax > 0°C; r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of Central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes.

中文翻译：

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西伯利亚中部落叶松占主导地位的永久冻土带内气候引起的滑坡

在与中西伯利亚连续多年冻土区相关的落叶松占主导地位的社区内分析了气候对滑坡发生和空间格局的影响。我们使用高分辨率卫星图像（即 QuickBird、WorldView）来识别 62000 平方公里区域内的滑坡疤痕。针对气候变量（气温、降水、干旱指数 SPEI）和 GRACE 卫星得出的等效水厚度异常 (EWTA) 分析了滑坡的发生。滑坡仅出现在朝南的斜坡上，随着坡度的增加，滑坡的发生率呈指数增长。滑坡长度与坡度呈正相关。观测到的滑坡海拔上限往往与林木线重合。观测显示，山体滑坡的发生还与 8 月降水（r = 0.81）和干旱指数（r = 0.7）、6-7-8 月土壤水分异常（即 EWTA，r = 0.68-0.7）密切相关，并且解冻天数（即 tmax > 0°C 的天数；r = 0.67）。观察到土壤水分异常的方差显着增加，表明即使在平均降水水平稳定的情况下，滑坡的发生可能会增加。本研究的主要发现是：（1）21世纪初中西伯利亚多年冻土带滑坡发生增多；(2) 极端降水和土壤水分异常是滑坡发生增多的主要原因；(3) 滑坡的发生强烈依赖于朝南的陡坡等地貌特征。