Rapid vegetation recovery at landslide scars detected by multitemporal high-resolution satellite imagery at Aso volcano, Japan
Rapid vegetation recovery at landslide scars detected by multitemporal high-resolution satellite imagery at Aso volcano, Japan
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DOI：
10.1016/j.geomorph.2021.107989
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发表时间：
2021-10
期刊：
影响因子：
3.9
通讯作者：
H. Saito;S. Uchiyama;Koki Teshirogi
中科院分区：
文献类型：
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作者：
H. Saito;S. Uchiyama;Koki Teshirogi
植被覆盖是影响山坡稳定性和滑坡易发性的重要因素。本研究的目的是探讨植被恢复在地震引起的和同震滑坡疤痕在日本阿索火山。利用2010 - 2019年RapidEye和2016 - 2020年PlanetScope的多时相卫星图像以及无人机（UAV）的更高空间分辨率图像，重点研究了地形的时间变化和对植被恢复的影响。研究区以半天然草地为特征，2012年强降雨和2016年熊本地震引发的滑坡事件频繁。利用归一化植被指数（NDVI）和归一化植被指数比值（NDVI比值代表了滑坡疤痕区和草地区的NDVI相对差异）对草地植被恢复进行了验证。结果表明，暴雨和熊本地震后，滑坡痕迹处的植被指数明显下降。滑坡后，滑坡疤痕的NDVI比值迅速增加。结果表明，两个滑坡疤痕的NDVI将在12年内达到与滑坡前的草地植被相同的水平。坡向决定了草地植被恢复的地形效应。从北向西的滑坡疤痕似乎经历了快速的草植被恢复。
Vegetation cover is an important factor in hillslope stability and landslide susceptibility. The objective of this study is to explore vegetation recovery in rainfall-induced and coseismic landslide scars at the Aso volcano in Japan. We focus on the temporal changes and effect of topography on vegetation recovery using multitemporal satellite images of RapidEye from 2010 to 2019 and PlanetScope from 2016 to 2020 and finer spatial resolution images of unmanned aerial vehicles (UAVs). The study area is characterized by semi-natural grassland and frequent landslide events triggered by heavy rainfall in 2012 and the 2016 Kumamoto earthquake. This study validates grass vegetation recovery using the normalized difference vegetation index (NDVI) and NDVI ratio, which represents the relative difference in NDVI between the landslide scars and grass areas. The results show a distinct decrease in the NDVI ratio at landslide scars after the heavy rainfall and Kumamoto earthquake. The NDVI ratio rapidly increases in landslide scars after the events. The results indicate that NDVI at both landslide scars will reach the same level as the pre-landslide grass vegetation within 12 years. The slope aspect direction determines the topographic effects of grass vegetation recovery. The north- to west-facing landslide scars seemed to experience rapid grass vegetation recovery.