@article{BaroniFrancke2020, author = {Baroni, Gabriele and Francke, Till}, title = {An effective strategy for combining variance- and distribution-based global sensitivity analysis}, series = {Environmental modelling \& software with environment data news}, volume = {134}, journal = {Environmental modelling \& software with environment data news}, publisher = {Elsevier}, address = {Oxford}, issn = {1364-8152}, doi = {10.1016/j.envsoft.2020.104851}, pages = {14}, year = {2020}, abstract = {We present a new strategy for performing global sensitivity analysis capable to estimate main and interaction effects from a generic sampling design. The new strategy is based on a meaningful combination of varianceand distribution-based approaches. The strategy is tested on four analytic functions and on a hydrological model. Results show that the analysis is consistent with the state-of-the-art Saltelli/Jansen formula but to better quantify the interaction effect between the input factors when the output distribution is skewed. Moreover, the estimation of the sensitivity indices is much more robust requiring a smaller number of simulations runs. Specific settings and alternative methods that can be integrated in the new strategy are also discussed. Overall, the strategy is considered as a new simple and effective tool for performing global sensitivity analysis that can be easily integrated in any environmental modelling framework.}, language = {en} } @article{BaroniOrtuaniFacchietal.2013, author = {Baroni, Gabriele and Ortuani, B. and Facchi, A. and Gandolfi, C.}, title = {The role of vegetation and soil properties on the spatio-temporal variability of the surface soil moisture in a maize-cropped field}, series = {Journal of hydrology}, volume = {489}, journal = {Journal of hydrology}, number = {7}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2013.03.007}, pages = {148 -- 159}, year = {2013}, abstract = {Soil moisture dynamics are affected by complex interactions among several factors. Understanding the relative importance of these factors is still an important challenge in the study of water fluxes and solute transport in unsaturated media. In this study, the spatio-temporal variability of surface soil moisture was investigated in a 10 ha flat cropped field located in northern Italy. Soil moisture was measured on a regular 50 x 50 m grid on seven dates during the growing season. For each measurement campaign, the spatial variability of the soil moisture was compared with the spatial variability of the soil texture and crop properties. In particular, to better understand the role of the vegetation, the spatio-temporal variability of two different parameters - leaf area index and crop height - was monitored on eight dates at different crop development stages. Statistical and geostatistical analysis was then applied to explore the interactions between these variables. In agreement with other studies, the results show that the soil moisture variability changes according to the average value within the field, with the standard deviation reaching a maximum value under intermediate mean soil moisture conditions and the coefficient of variation decreasing exponentially with increasing mean soil moisture. The controls of soil moisture variability change according to the average soil moisture within the field. Under wet conditions, the spatial distribution of the soil moisture reflects the variability of the soil texture. Under dry conditions, the spatial distribution of the soil moisture is affected mostly by the spatial variability of the vegetation. The interaction between these two factors is more important under intermediate soil moisture conditions. These results confirm the importance of considering the average soil moisture conditions within a field when investigating the controls affecting the spatial variability of soil moisture. This study highlights the importance of considering the spatio-temporal variability of the vegetation in investigating soil moisture dynamics, especially under intermediate and dry soil moisture conditions. The results of this study have important implications in different hydrological applications, such as for sampling design, ranking stability application, indirect measurements of soil properties and model parameterisation.}, language = {en} } @article{BaroniOswald2015, author = {Baroni, Gabriele and Oswald, Sascha}, title = {A scaling approach for the assessment of biomass changes and rainfall interception using cosmic-ray neutron sensing}, series = {Journal of hydrology}, volume = {525}, journal = {Journal of hydrology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2015.03.053}, pages = {264 -- 276}, year = {2015}, abstract = {Cosmic-Ray neutron sensing (CRS) is a unique approach to measure soil moisture at field scale filling the gap of current methodologies. However, CRS signal is affected by all the hydrogen pools on the land surface and understanding their relative importance plays an important role for the application of the method e.g., validation of remote sensing products and data assimilation. In this study, a soil moisture scaling approach is proposed to estimate directly the correct CRS soil moisture based on the soil moisture profile measured at least in one position within the field. The approach has the advantage to avoid the need to introduce one correction for each hydrogen contribution and to estimate indirectly all the related time-varying hydrogen pools. Based on the data collected in three crop seasons, the scaling approach shows its ability to identify and to quantify the seasonal biomass water equivalent. Additionally, the analysis conducted at sub-daily time resolution is able to quantify the daily vertical redistribution of the water biomass and the rainfall interception, showing promising applications of the CRS method also for these types of measurements. Overall, the study underlines how not only soil moisture but all the specific hydrological processes in the soil-plant-atmosphere continuum should be considered for a proper evaluation of the CRS signal. For this scope, the scaling approach reveals to be a simple and pragmatic analysis that can be easily extended to other experimental sites. (C) 2015 Elsevier B.V. All rights reserved.}, language = {en} } @article{BaroniScheiffeleSchroenetal.2018, author = {Baroni, Gabriele and Scheiffele, Lena and Schr{\"o}n, Martin and Ingwersen, Joachim and Oswald, Sascha}, title = {Uncertainty, sensitivity and improvements in soil moisture estimation with cosmic-ray neutron sensing}, series = {Journal of hydrology}, volume = {564}, journal = {Journal of hydrology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1694}, doi = {10.1016/j.jhydrol.2018.07.053}, pages = {873 -- 887}, year = {2018}, abstract = {Cosmic-ray neutron sensing (CRNS) is a promising proximal soil sensing technique to estimate soil moisture at intermediate scale and high temporal resolution. However, the signal shows complex and non-unique response to all hydrogen pools near the land surface, providing some challenges for soil moisture estimation in practical applications. Aims of the study were 1) to assess the uncertainty of CRNS as a stand-alone approach to estimate volumetric soil moisture in cropped field 2) to identify the causes of this uncertainty 3) and possible improvements. Two experimental sites in Germany were equipped with a CRNS probe and point-scale soil moisture network. Additional monitoring activities were conducted during the crop growing season to characterize the soil-plant systems. This data is used to identify and quantify the different sources of uncertainty (factors). An uncertainty analysis, based on Monte Carlo approach, is applied to propagate these uncertainties to CRNS soil moisture estimations. In addition, a sensitivity analysis based on the Sobol' method is performed to identify the most important factors explaining this uncertainty. Results show that CRNS soil moisture compares well to the soil moisture network when these point-scale values are weighted to account for the spatial sensitivity of the signal and other sources of hydrogen (lattice water and organic carbon) are added to the water content. However, the performance decreases when CRNS is considered as a stand-alone method to retrieve the actual (non-weighted) volumetric soil moisture. The support volume (penetration depth and radius) shows also a considerable uncertainty, especially in relatively dry soil moisture conditions. Four of the seven factors analyzed (the vertical soil moisture profile, bulk density, incoming neutron correction and the calibrated parameter N0) were found to play an important role. Among the possible improvements identified, a simple correction factor based on vertical point-scale soil moisture profiles shows to be a promising approach to account for the sensitivity of the CRNS signal to the upper soil layers.}, language = {en} } @article{BaroniTarantola2014, author = {Baroni, Gabriele and Tarantola, S.}, title = {A general probabilistic framework for uncertainty and global sensitivity analysis of deterministic models: A hydrological case study}, series = {Environmental modelling \& software with environment data news}, volume = {51}, journal = {Environmental modelling \& software with environment data news}, publisher = {Elsevier}, address = {Oxford}, issn = {1364-8152}, doi = {10.1016/j.envsoft.2013.09.022}, pages = {26 -- 34}, year = {2014}, abstract = {The present study proposes a General Probabilistic Framework (GPF) for uncertainty and global sensitivity analysis of deterministic models in which, in addition to scalar inputs, non-scalar and correlated inputs can be considered as well. The analysis is conducted with the variance-based approach of Sobol/Saltelli where first and total sensitivity indices are estimated. The results of the framework can be used in a loop for model improvement, parameter estimation or model simplification. The framework is applied to SWAP, a 113 hydrological model for the transport of water, solutes and heat in unsaturated and saturated soils. The sources of uncertainty are grouped in five main classes: model structure (soil discretization), input (weather data), time-varying (crop) parameters, scalar parameters (soil properties) and observations (measured soil moisture). For each source of uncertainty, different realizations are created based on direct monitoring activities. Uncertainty of evapotranspiration, soil moisture in the root zone and bottom fluxes below the root zone are considered in the analysis. The results show that the sources of uncertainty are different for each output considered and it is necessary to consider multiple output variables for a proper assessment of the model. Improvements on the performance of the model can be achieved reducing the uncertainty in the observations, in the soil parameters and in the weather data. Overall, the study shows the capability of the GPF to quantify the relative contribution of the different sources of uncertainty and to identify the priorities required to improve the performance of the model. The proposed framework can be extended to a wide variety of modelling applications, also when direct measurements of model output are not available.}, language = {en} } @article{BaroniZinkKumaretal.2017, author = {Baroni, Gabriele and Zink, Matthias and Kumar, Rohini and Samaniego, Luis and Attinger, Sabine}, title = {Effects of uncertainty in soil properties on simulated hydrological states and fluxes at different spatio-temporal scales}, series = {Hydrology and earth system sciences : HESS}, volume = {21}, journal = {Hydrology and earth system sciences : HESS}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1027-5606}, doi = {10.5194/hess-21-2301-2017}, pages = {2301 -- 2320}, year = {2017}, abstract = {Soil properties show high heterogeneity at different spatial scales and their correct characterization remains a crucial challenge over large areas. The aim of the study is to quantify the impact of different types of uncertainties that arise from the unresolved soil spatial variability on simulated hydrological states and fluxes. Three perturbation methods are presented for the characterization of uncertainties in soil properties. The methods are applied on the soil map of the upper Neckar catchment (Germany), as an example. The uncertainties are propagated through the distributed mesoscale hydrological model (mHM) to assess the impact on the simulated states and fluxes. The model outputs are analysed by aggregating the results at different spatial and temporal scales. These results show that the impact of the different uncertainties introduced in the original soil map is equivalent when the simulated model outputs are analysed at the model grid resolution (i.e. 500 m). However, several differences are identified by aggregating states and fluxes at different spatial scales (by subcatchments of different sizes or coarsening the grid resolution). Streamflow is only sensitive to the perturbation of long spatial structures while distributed states and fluxes (e.g. soil moisture and groundwater recharge) are only sensitive to the local noise introduced to the original soil properties. A clear identification of the temporal and spatial scale for which finer-resolution soil information is (or is not) relevant is unlikely to be universal. However, the comparison of the impacts on the different hydrological components can be used to prioritize the model improvements in specific applications, either by collecting new measurements or by calibration and data assimilation approaches. In conclusion, the study underlines the importance of a correct characterization of uncertainty in soil properties. With that, soil maps with additional information regarding the unresolved soil spatial variability would provide strong support to hydrological modelling applications.}, language = {en} } @phdthesis{Barrionuevo2020, author = {Barrionuevo, Mat{\´i}as}, title = {The role of the upper plate in the Andean tectonic evolution (33-36°S): insights from structural geology and numerical modeling}, doi = {10.25932/publishup-51590}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515909}, school = {Universit{\"a}t Potsdam}, pages = {148, S2}, year = {2020}, abstract = {Los Andes Centrales del Sur (33-36°S) son un gran laboratorio para el estudio de los procesos de deformaci{\´o}n orog{\´e}nica, donde las condiciones de borde, como la geometr{\´i}a de la placa subductada, imponen un importante control sobre la deformaci{\´o}n andina. Por otro lado, la Placa Sudamericana presenta una serie de heterogeneidades que tambi{\´e}n imparten un control sobre el modo de deformaci{\´o}n. El objetivo de esta tesis es probar el control de este {\´u}ltimo factor sobre la construcci{\´o}n del sistema orog{\´e}nico andino. A partir de la integraci{\´o}n de la informaci{\´o}n superficial y de subsuelo en el {\´a}rea sur (34°-36°S), se estudi{\´o} la evoluci{\´o}n de la deformaci{\´o}n andina sobre el segmento de subducci{\´o}n normal. Se desarroll{\´o} un modelo estructural que eval{\´u}a el estado de esfuerzos desde el Mioceno hasta la actualidad, el rol de estructuras previas y su influencia en la migraci{\´o}n de fluidos. Con estos datos y publicaciones previas de la zona norte del {\´a}rea de estudio (33°-34ºS), se realiz{\´o} un modelado num{\´e}rico geodin{\´a}mico para probar la hip{\´o}tesis del papel de las heterogeneidades de la placa superior en la evoluci{\´o}n andina. Se utilizaron dos c{\´o}digos (LAPEX-2D y ASPECT) basados en elementos finitos/diferencias finitas, que simulan el comportamiento de materiales con reolog{\´i}as elastoviscopl{\´a}sticas bajo deformaci{\´o}n. Los resultados del modelado sugieren que la deformaci{\´o}n contraccional de la placa superior est{\´a} significativamente controlada por la resistencia de la lit{\´o}sfera, que est{\´a} definida por la composici{\´o}n de la corteza superior e inferior y por la proporci{\´o}n del manto litosf{\´e}rico, que a su vez est{\´a} definida por eventos tect{\´o}nicos previos. Estos eventos previos tambi{\´e}n definieron la composici{\´o}n de la corteza y su geometr{\´i}a, que es otro factor que controla la localizaci{\´o}n de la deformaci{\´o}n. Con una composici{\´o}n de corteza inferior m{\´a}s f{\´e}lsica, la deformaci{\´o}n sigue un modo de cizalla pura mientras que las composiciones m{\´a}s m{\´a}ficas provocan un modo de deformaci{\´o}n tipo cizalla simple. Por otro lado, observamos que el espesor inicial de la lit{\´o}sfera controla la localizaci{\´o}n de la deformaci{\´o}n, donde zonas con lit{\´o}sfera m{\´a}s fina es propensa a concentrar la deformaci{\´o}n. Un l{\´i}mite lit{\´o}sfera-asten{\´o}sfera asim{\´e}trico, como resultado del flujo de la cu{\~n}a mant{\´e}lica tiende a generar despegues vergentes al E.}, language = {en} } @article{BarthGeertsemaBevingtonetal.2019, author = {Barth, Sophia and Geertsema, Marten and Bevington, Alexandre R. and Bird, Alison L. and Clague, John J. and Millard, Tom and Bobrowsky, Peter T. and Hasler, Andreas and Liu, Hongjiang}, title = {Landslide response to the 27 October 2012 earthquake (M-W 7.8), southern Haida Gwaii, British Columbia, Canada}, series = {Landslides : journal of the International Consortium on Landslides, ICL}, volume = {17}, journal = {Landslides : journal of the International Consortium on Landslides, ICL}, number = {3}, publisher = {Springer}, address = {Heidelberg}, issn = {1612-510X}, doi = {10.1007/s10346-019-01292-7}, pages = {517 -- 526}, year = {2019}, abstract = {In this paper, we examine the influence of the 27 October 2012, M-w 7.8 earthquake on landslide occurrence in the southern half of Haida Gwaii (formerly Queen Charlotte Islands), British Columbia, Canada. Our 1350 km(2) study area is undisturbed, primarily forested terrain that has not experienced road building or timber harvesting. Our inventory of landslide polygons is based on optical airborne and spaceborne images acquired between 2007 and 2018, from which we extracted and mapped 446 individual landslides (an average of 33 landslides per 100 km(2)). The landslide rate in years without major earthquakes averages 19.4 per year, or 1.4/100 km(2)/year, and the annual average area covered by non-seismically triggered landslides is 35 ha/year. The number of landslides identified in imagery closely following the 2012 earthquake, and probably triggered by it, is 244 or an average of about 18 landslides per 100 km(2). These landslides cover a total area of 461 ha. In the following years-2013-2016 and 2016-2018-the number of landslides fell, respectively, to 26 and 13.5 landslides per year. In non-earthquake years, most landslides happen on south-facing slopes, facing the prevailing winds. In contrast, during or immediately after the earthquake, up to 32\% of the landslides occurred on north and northwest-facing slopes. Although we could not find imagery from the day after the earthquake, overview reconnaissance flights 10 and 16 days later showed that most of the landslides were recent, suggesting they were co-seismic.}, language = {en} } @article{BartholdTurnerElsenbeeretal.2017, author = {Barthold, Frauke Katrin and Turner, Benjamin L. and Elsenbeer, Helmut and Zimmermann, Alexander}, title = {A hydrochemical approach to quantify the role of return flow in a surface flow-dominated catchment}, series = {Hydrological processes}, volume = {31}, journal = {Hydrological processes}, number = {5}, publisher = {Wiley}, address = {Hoboken}, issn = {0885-6087}, doi = {10.1002/hyp.11083}, pages = {1018 -- 1033}, year = {2017}, abstract = {Stormflow generation in headwater catchments dominated by subsurface flow has been studied extensively, yet catchments dominated by surface flow have received less attention. We addressed this by testing whether stormflow chemistry is controlled by either (a) the event-water signature of overland flow, or (b) the pre-event water signature of return flow. We used a high-resolution hydrochemical data set of stormflow and end-members of multiple storms in an end-member mixing analysis to determine the number of end-members needed to explain stormflow, characterize and identify potential end-members, calculate their contributions to stormflow, and develop a conceptual model of stormflow. The arrangement and relative positioning of end-members in stormflow mixing space suggest that saturation excess overland flow (26-48\%) and return flow from two different subsurface storage pools (17-53\%) are both similarly important for stormflow. These results suggest that pipes and fractures are important flow paths to rapidly release stored water and highlight the value of within-event resolution hydrochemical data to assess the full range and dynamics of flow paths.}, language = {en} } @article{BartholdTyrallaSchneideretal.2011, author = {Barthold, Frauke Katrin and Tyralla, Christoph and Schneider, Katrin and Vache, Kellie B. and Frede, Hans-Georg and Breuer, Lutz}, title = {How many tracers do we need for end member mixing analysis (EMMA)? - a sensitivity analysis}, series = {Water resources research}, volume = {47}, journal = {Water resources research}, number = {7360}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0043-1397}, doi = {10.1029/2011WR010604}, pages = {14}, year = {2011}, abstract = {End member mixing analysis (EMMA) is a commonly applied method to identify and quantify the dominant runoff producing sources of water. It employs tracers to determine the dimensionality of the hydrologic system. Many EMMA studies have been conducted using two to six tracers, with some of the main tracers being Ca, Na, Cl(-), water isotopes, and alkalinity. Few studies use larger tracer sets including minor trace elements such as Li, Rb, Sr, and Ba. None of the studies has addressed the question of the tracer set size and composition, despite the fact that these determine which and how many end members (EM) will be identified. We examine how tracer set size and composition affects the conceptual model that results from an EMMA. We developed an automatic procedure that conducts EMMA while iteratively changing tracer set size and composition. We used a set of 14 tracers and 9 EMs. The validity of the resulting conceptual models was investigated under the aspects of dimensionality, EM combinations, and contributions to stream water. From the 16,369 possibilities, 23 delivered plausible results. The resulting conceptual models are highly sensitive to the tracer set size and composition. The moderate reproducibility of EM contributions indicates a still missing EM. It also emphasizes that the major elements are not always the most useful tracers and that larger tracer sets have an enhanced capacity to avoid false conclusions about catchment functioning. The presented approach produces results that may not be apparent from the traditional approach and it is a first step to add the idea of statistical significance to the EMMA approach.}, language = {en} }