@article{UlloaIroumePiccoetal.2016,
  author    = {Ulloa, H. and Iroume, A. and Picco, L. and Mohr, Christian Heinrich and Mazzorana, B. and Lenzi, Mario Aristide and Mao, L.},
  title     = {Spatial analysis of the impacts of the Chaiten volcano eruption (Chile) in three fluvial systems},
  series = {Journal of South American earth sciences},
  volume    = {69},
  journal   = {Journal of South American earth sciences},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0895-9811},
  doi       = {10.1016/j.jsames.2016.04.008},
  pages     = {213 -- 225},
  year      = {2016},
  abstract  = {The eruption of the Chaiten volcano in May 2008 generated morphological and ecological disturbances in adjacent river basins, and the magnitude of these disturbances depended on the type of dominant volcanic process affecting each of them. The aim of this study is to analyse the morphological changes in different periods in river segments of the Blanco, El Amarillo and Rayas river basins located near the Chaiten volcano. These basins suffered disturbances of different intensity and spatial distribution caused by tephra fall, dome collapses and pyroclastic density currents that damaged hillslope forests, widened channels and destroyed island and floodplain vegetation. Changes continued to occur in the fluvial systems in the years following the eruption, as a consequence of the geomorphic processes indirectly induced by the eruption. Channel changes were analyzed by comparing remote images of pre and post eruption conditions. Two periods were considered: the first from 2008 to 2009-2010 associated with the explosive and effusive phases of the eruption and the second that correspond to the post-eruption stage from 2009-2010 to 2013. Following the first phases channel segments widened 91\% (38 m/yr), 6\% (7 m/yr) and 7\% (22 m/yr) for Blanco, Rayas and El Amarillo Rivers, respectively, compared to pre-eruption condition. In the second period, channel segments additionally widened 42\% (8 m/yr), 2\% (2 m/yr) and 5\% (4 m/yr) for Blanco, Rayas and El Amarillo Rivers, respectively. In the Blanco River 62 and 82\% of the islands disappeared in the first and second period, respectively, which is 6-8 times higher than in the El Amarillo approximately twice the Rayas. Sinuosity increased after the eruption only in the Blanco River but the three study channels showed a high braiding intensity mainly during the first post-eruption period. The major disturbances occurred during the eruptive and effusive phases of Chaiten volcano, and the intensity of these disturbances reflects the magnitude of the dominant volcanic processes affecting each basin. Inputs of sediment from dome collapses and pyroclastic density currents and not ash fall seem to explain morphologic channel change magnitudes in the study segments. The resulting knowledge can facilitate land use planning and design of river restoration projects in areas affected by volcanic eruptions disturbances. (C) 2016 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{MohrZimmermannKorupetal.2014,
  author    = {Mohr, Christian Heinrich and Zimmermann, Andreas and Korup, Oliver and Iroume, A. and Francke, Till and Bronstert, Axel},
  title     = {Seasonal logging, process response, and geomorphic work},
  series = {Earth surface dynamics},
  volume    = {2},
  journal   = {Earth surface dynamics},
  number    = {1},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {2196-6311},
  doi       = {10.5194/esurf-2-117-2014},
  pages     = {117 -- 125},
  year      = {2014},
  abstract  = {Deforestation is a prominent anthropogenic cause of erosive overland flow and slope instability, boosting rates of soil erosion and concomitant sediment flux. Conventional methods of gauging or estimating post-logging sediment flux often focus on annual timescales but overlook potentially important process response on shorter intervals immediately following timber harvest. We resolve such dynamics with non-parametric quantile regression forests (QRF) based on high-frequency (3 min) discharge measurements and sediment concentration data sampled every 30-60 min in similar-sized (similar to 0.1 km(2)) forested Chilean catchments that were logged during either the rainy or the dry season. The method of QRF builds on the random forest algorithm, and combines quantile regression with repeated random sub-sampling of both cases and predictors. The algorithm belongs to the family of decision-tree classifiers, which allow quantifying relevant predictors in high-dimensional parameter space. We find that, where no logging occurred, similar to 80\% of the total sediment load was transported during extremely variable runoff events during only 5\% of the monitoring period. In particular, dry-season logging dampened the relative role of these rare, extreme sediment-transport events by increasing load efficiency during more efficient moderate events. We show that QRFs outperform traditional sediment rating curves (SRCs) in terms of accurately simulating short-term dynamics of sediment flux, and conclude that QRF may reliably support forest management recommendations by providing robust simulations of post-logging response of water and sediment fluxes at high temporal resolution.},
  language  = {en}
}