Abstract In this study, we analysed the morphological evolution of a channel segment in the Blanco River in southern Chile that was affected by the Chaiten Volcano eruption occurred in 2008–2009. Through a series of high-resolution satellite images from 2005 to 2019 that represents the entire pre- and post-eruptive dynamics and land covers, we tracked the geomorphological evolution of a 5.65-km-long river segment using channel form indices and also monitored the vegetation dynamics using object-based image analysis (OBIA). Discharge record for the Blanco River was also reconstructed to support the analysis of channel morphologic process. The study aims at examining whether a) the river channel is still adjusting 10 years after the eruption and if so, at what magnitude and, b) the recovered riparian vegetation plays a significant role in stabilising the river streambanks and terraces. We found that even 10 years after the eruption, the Blanco River channel planform is still adjusting, showing a simpler and stable channel configuration in the upstream reaches of the valley, where a certain degree of equilibrium appears to have been attained. More dynamic morphologies were observed in the reaches downstream that have to accommodate the arrival of large amounts of freshly eroded sediments. Our analysis showed that the occurrence of competent floods capable of reworking the river channel matches with the geomorphic indices and mark the post-eruption adjustments of the channel. Finally, the in-channel and riparian vegetation does not play a significant role in stabilising the active channel, streambanks, and terraces, reinforcing the recolonization of sedimentary active areas occurring elsewhere in the valley.

中文翻译：

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智利南部布兰科河的喷发后形态演变和植被动态

摘要 在这项研究中，我们分析了智利南部布兰科河中受 2008-2009 年柴腾火山喷发影响的河道段的形态演变。通过从 2005 年到 2019 年的一系列代表整个喷发前后动态和土地覆盖的高分辨率卫星图像，我们使用河道形态指数跟踪了 5.65 公里长的河段的地貌演变，并监测了使用基于对象的图像分析 (OBIA) 的植被动态。布兰科河的流量记录也被重建，以支持河道形态过程的分析。该研究旨在检查 a) 河道在喷发 10 年后是否仍在调整，如果是，幅度如何，以及，b) 恢复的河岸植被在稳定河岸和阶地方面发挥着重要作用。我们发现，即使在喷发 10 年后，布兰科河航道平面仍在调整，在河谷上游显示出更简单稳定的航道配置，似乎已经达到了一定程度的平衡。在下游河段观察到更多动态形态，必须适应大量新侵蚀沉积物的到来。我们的分析表明，能够改造河道的有能力洪水的发生与地貌指数相匹配，标志着河道的喷发后调整。最后，河道内和河岸植被在稳定活动河道、河岸和阶地方面没有发挥重要作用，