Earthquake ground motion often triggers landslides in mountainous areas. A simple, robust method to quickly evaluate the terrain's susceptibility of specific locations to earthquake-triggered landslides is important for planning field reconnaissance and rescues after earthquakes. Different approaches have been used to estimate coseismic landslide susceptibility using Newmark’s sliding block model. This model requires an estimate of the landslide depth or thickness, which is a difficult parameter to estimate. We illustrate the use of Newmark sliding block’s critical acceleration for a glaciated valley affected by the 2015 Gorkha earthquake in Nepal. The landslide data came from comparing high-resolution pre- and post-earthquake digital elevation models (DEMs) derived from Spot 6/7 images. The areas where changes were detected provided an inventory of all the landslides triggered by the earthquake. The landslide susceptibility was modeled in a GIS environment using as inputs the pre-earthquake terrain and slope angles, the peak ground acceleration from the 2015 Gorkha earthquake, and a geological map. We exploit the depth information for the landslides (obtained by DEM difference) to apply the critical acceleration model. The spatial distribution of the predicted earthquake-triggered landslides matched the actual landslides when the assumed landslide thickness in the model is close to the median value of the actual landslide thickness (2.6 m in this case). The landslide predictions generated a map of landslide locations close to those observed and demonstrated the applicability of critical acceleration for rapidly creating a map of earthquake-triggered landslides.

中文翻译：

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具有高分辨率 DEM 和临界加速度的地震触发滑坡敏感性快速地形评估

地震地面运动经常在山区引发山体滑坡。一种简单、可靠的方法可以快速评估特定位置的地形对地震引发的滑坡的敏感性，这对于规划地震后的现场勘察和救援非常重要。使用 Newmark 的滑块模型，已经使用了不同的方法来估计同震滑坡的敏感性。该模型需要估计滑坡深度或厚度，这是一个难以估计的参数。我们说明了纽马克滑块临界加速度在受 2015 年尼泊尔廓尔喀地震影响的冰川山谷中的使用。滑坡数据来自比较来自 Spot 6/7 图像的高分辨率震前和震后数字高程模型 (DEM)。检测到变化的区域提供了地震引发的所有滑坡的清单。在 GIS 环境中对滑坡敏感性进行建模，使用震前地形和坡度角、2015 年廓尔喀地震的峰值地面加速度和地质图作为输入。我们利用滑坡的深度信息（通过 DEM 差异获得）来应用临界加速度模型。当模型中假设的滑坡厚度接近实际滑坡厚度的中值（在这种情况下为2.6 m）时，预测的地震触发滑坡的空间分布与实际滑坡匹配。