@phdthesis{Samaniego2021,
  author    = {Samaniego, Luis},
  title     = {Drought modeling and forecasting},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xxvii, 273},
  year      = {2021},
  abstract  = {Over millennia, droughts could not be understood or defined but rather were associated with mystical connotations. To understand this natural hazards, we first needed to understand the laws of physics and then develop plausible explanations of inner workings of the hydrological cycle. Consequently, modeling and predicting droughts was out of the scope of mankind until the end of the last century. In recent studies, it is estimated that this natural hazard has caused billions of dollars in losses since 1900 and that droughts have affected 2.2 billion people worldwide between 1950 and 2014. For these reasons, droughts have been identified by the IPCC as the trigger of a web of impacts across many sectors leading to land degradation, migration and substantial socio-economic costs. This thesis summarizes a decade of research carried out at the Helmholtz Centre for Environmental Research on the subject of drought monitoring, modeling, and forecasting, from local to continental scales. The overarching objectives of this study, systematically addressed in the twelve previous chapters, are: 1) Create the capability to seamless monitor and predict water fluxes at various spatial resolutions and temporal scales varying from days to centuries; 2) Develop and test a modeling chain for monitoring, forecasting and predicting drought events and related characteristics at national and continental scales; and 3) Develop drought indices and impact indicators that are useful for end-users. Key outputs of this study are: the development of the open source model mHM, the German Drought Monitor System, the proof of concept for an European multi-model for improving water managent from local to continental scales, and the prototype of a crop-yield drought impact model for Germany.},
  language  = {en}
}
@misc{RevereyGrossartPremkeetal.2016,
  author    = {Reverey, Florian and Großart, Hans-Peter and Premke, Katrin and Lischeid, Gunnar},
  title     = {Carbon and nutrient cycling in kettle hole sediments depending on hydrological dynamics: a review},
  series = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica},
  volume    = {775},
  journal   = {Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0018-8158},
  doi       = {10.1007/s10750-016-2715-9},
  pages     = {1 -- 20},
  year      = {2016},
  abstract  = {Kettle holes as a specific group of isolated, small lentic freshwater systems (LFS) often are (i) hot spots of biogeochemical cycling and (ii) exposed to frequent sediment desiccation and rewetting. Their ecological functioning is greatly determined by immanent carbon and nutrient transformations. The objective of this review is to elucidate effects of a changing hydrological regime (i.e., dry-wet cycles) on carbon and nutrient cycling in kettle hole sediments. Generally, dry-wet cycles have the potential to increase C and N losses as well as P availability. However, their duration and frequency are important controlling factors regarding direction and intensity of biogeochemical and microbiological responses. To evaluate drought impacts on sediment carbon and nutrient cycling in detail requires the context of the LFS hydrological history. For example, frequent drought events induce physiological adaptation of exposed microbial communities and thus flatten metabolic responses, whereas rare events provoke unbalanced, strong microbial responses. Different potential of microbial resilience to drought stress can irretrievably change microbial communities and functional guilds, gearing cascades of functional responses. Hence, dry-wet events can shift the biogeochemical cycling of organic matter and nutrients to a new equilibrium, thus affecting the dynamic balance between carbon burial and mineralization in kettle holes.},
  language  = {en}
}
@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}
}