Periglacial vegetation dynamics in Arctic Russia: decadal analysis of tundra regeneration on landslides with time series satellite imagery
Periglacial vegetation dynamics in Arctic Russia: decadal analysis of tundra regeneration on landslides with time series satellite imagery
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DOI：
10.1088/1748-9326/abb500
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发表时间：
2020-09
影响因子：
6.7
通讯作者：
Mariana Verdonen;L. Berner;B. Forbes;T. Kumpula
中科院分区：
文献类型：
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作者：
Mariana Verdonen;L. Berner;B. Forbes;T. Kumpula
据报告，北极地区的植被生产力根据归一化植被指数变化。大多数研究使用非常粗糙的空间分辨率遥感数据，无法隔离景观水平的因素。例如，在西西伯利亚的亚马尔半岛，杨柳的生长增强与广泛的滑坡活动有关，但滑坡对区域NDVI动态的影响尚不清楚。在这里，我们应用一种新的基于卫星的NDVI分析，调查植被再生模式的活动层determination后，在1989年的重大滑坡事件。我们分析了QuickBird-2和WorldView-2和3的Landsat和甚高分辨率（VHR）图像的时间序列数据，这些数据表征了一个约为1000平方公里的研究区域。35平方公里。陆地卫星显示，在滑坡事件发生后的头二十年里，北极低苔原的自然再生进展迅速。然而，在过去的十年中，滑坡剪切面和周围地区的差异保持相对不变，尽管植被演替的进步。时间序列还显示，自2013年以来，研究区域内的NDVI普遍下降。VHR图像可以检测归一化差异植被指数变化的“热点”，包括植被覆盖的暂时退化，以及新的和扩大的融化滑坡，这是太小，从陆地卫星数据检测。我们的研究表明，山体滑坡可以对苔原植被产生明显和持久的影响。随着持续变暖，西伯利亚西北部和其他北极地区的热岩溶滑坡及其对植被的影响可能会越来越普遍。
Changes in vegetation productivity based on normalized difference vegetation index (NDVI) have been reported from Arctic regions. Most studies use very coarse spatial resolution remote sensing data that cannot isolate landscape level factors. For example, on Yamal Peninsula in West Siberia enhanced willow growth has been linked to widespread landslide activity, but the effect of landslides on regional NDVI dynamics is unknown. Here we apply a novel satellite-based NDVI analysis to investigate the vegetation regeneration patterns of active-layer detachments following a major landslide event in 1989. We analyzed time series data of Landsat and very high-resolution (VHR) imagery from QuickBird-2 and WorldView-2 and 3 characterizing a study area of ca. 35 km2. Landsat revealed that natural regeneration of low Arctic tundra progressed rapidly during the first two decades after the landslide event. However, during the past decade, the difference between landslide shear surfaces and surrounding areas remained relatively unchanged despite the advance of vegetation succession. Time series also revealed that NDVI generally declined since 2013 within the study area. The VHR imagery allowed detection of NDVI change ‘hot-spots’ that included temporary degradation of vegetation cover, as well as new and expanding thaw slumps, which were too small to be detected from Landsat satellite data. Our study demonstrates that landslides can have pronounced and long-lasting impacts on tundra vegetation. Thermokarst landslides and associated impacts on vegetation will likely become increasingly common in NW Siberia and other Arctic regions with continued warming.