@article{LopezLopezTarazonCasasRuizetal.2016,
  author    = {Lopez, Pilar and L{\´o}pez-Taraz{\´o}n, Jos{\´e} Andr{\´e}s and Casas-Ruiz, Joan P. and Pompeo, Marcelo and Ordonez, Jaime and Munoz, Isabel},
  title     = {Sediment size distribution and composition in a reservoir affected by severe water level fluctuations},
  series = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man},
  volume    = {540},
  journal   = {The science of the total environment : an international journal for scientific research into the environment and its relationship with man},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0048-9697},
  doi       = {10.1016/j.scitotenv.2015.06.033},
  pages     = {158 -- 167},
  year      = {2016},
  abstract  = {The reservoir sediments are important sinks for organic carbon (OC), the OC burial being dependent on two opposite processes, deposition and mineralization. Hence factors such as severe water level fluctuations are expected to influence the rate of OC accumulation as they may affect both deposition and mineralization. The Barasona Reservoir has been historically threatened by siltation, whilst the use of water for irrigation involves a drastic decrease of the water level. In this context, we have studied the physical and chemical characteristics (grain size, major and minor elemental compositions, organic and inorganic carbon, and nitrogen) of the recent sediments of the Barasona Reservoir and the relationships among them in order to: a) elucidate the main processes governing OC accumulation, b) evaluate the rate of OC mineralization and c) approach the effect of drought on the sediment characteristics in this system. Our results indicated that Barasona sediments were dominated by fine silts (>60\%) and clays (>20\%), the mean particle size decreasing from tail to dam. Desiccation increased particle sorting and size distribution became bimodal, but no effect on average size was observed. Attending to the composition, Barasona sediments were very homogeneous with low concentrations of nitrogen (TN) and phosphorus (<12 g kg(-1) dw and <0.6 g kg(-1) dw, respectively) and high concentration of OC (approximate to 36 kg(-1) dw). TN was negatively related to dry weight Sediment mixing due to drastic changes in water level may have favoured the observed homogeneity of Barasona sediments affecting carbon, major ions and grain size. The high amount of OC deposited in Barasona sediment suggested that the adsorption of OC onto fine particles was more important than in boreal lakes. The rate of oxygen consumption by wet sediment ranged from 2.26 to 3.15 mg O-2 m(-2) day(-1), values close to those compiled for Mediterranean running waters. (C) 2015 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{UlloaIrournePiccoetal.2015,
  author    = {Ulloa, Hector and Irourne, Andres and Picco, Lorenzo and Korup, Oliver and Lenzi, Mario Aristide and Mao, Luca and Ravazzolo, Diego},
  title     = {Massive biomass flushing despite modest channel response in the Rayas River following the 2008 eruption of Chaiten volcano, Chile},
  series = {Geomorphology : an international journal on pure and applied geomorphology},
  volume    = {250},
  journal   = {Geomorphology : an international journal on pure and applied geomorphology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0169-555X},
  doi       = {10.1016/j.geomorph.2015.09.019},
  pages     = {397 -- 406},
  year      = {2015},
  abstract  = {The 2008 eruption of Chaiten volcano in southern Chile severely impacted several densely forested river catchments by supplying excess pyroclastic sediment to the channel networks. Our aim is to substantiate whether and how channel geometry and forest stands changed in the Rayas River following the sudden input of pyroclastic sediment. We measured the resulting changes to channel geometry and riparian forest stands along 17.6 km of the impacted gravel-bed Rayas River (294 km(2)) from multiple high-resolution satellite images, aerial photographs, and fieldwork to quantify yield volume characteristics of the forest stands. Limited channel changes during the last 60 years before the eruption reflect a dynamic equilibrium condition of the river corridor, despite the high annual precipitation and the sediment supply from Chaiten and Michinmahuida volcanoes in the headwaters. Images taken in 1945, 2004, and 2005 show that total size of the vegetated channel islands nearly doubled between 1945 and 2004 and remained unchanged between 2004 and 2005. Pyroclastic sediment entering the Rayas River after the 2008 eruption caused only minor average channel widening (7\%), but killed all island vegetation in the study reach. Substantial shifts in the size distribution of in-channel vegetation patches reflect losses in total island area of 46\% from 2005 to 2009 and an additional 34\% from 2009 to 2012. The estimated pulsed release of organic carbon into the channel, mainly in the form of large wood from obliterated island and floodplain forests, was 78-400 tC/km/y and surpasses most documented yields from small mountainous catchments with similar rainfall, forest cover, and disturbance history, while making up between 20\% and 60\% of the annual carbon burial rate of fluvial sediments in the northern Patagonian fjords. We conclude that the carbon footprint of the 2008 Chaiten eruption on the Rayas River was more significant than the measured geomorphic impacts on channel geometry for the first five years following disturbance. The modest post-eruptive geomorphic response in this river is a poor indicator of its biogeochemical response. (C) 2015 Elsevier B.V. All rights reserved.},
  language  = {en}
}