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One decade(2011–2020)of European agricultural water stress monitoring by MSG-SEVIRI:workflow implementation on the Virtual Earth Laboratory(VLab)platform

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International Journal of Digital Earth 2022年第1期15卷 730-747页

作者： Bagher Bayat Carsten Montzka Alexander Graf Gregory Giuliani Mattia Santoro harry vereecken Institute of Bio-and Geosciences:Agrosphere (IBG-3) Forschungszentrum Jülich GmbHJülichGermany Institute for Environmental Sciences EnviroSPACE labUniversity of GenevaGenevaSwitzerland Institute of Atmospheric Pollution Research National Research Council of Italy (CNR)Sesto FiorentinoItaly

Cloud computing facilities can provide crucial computing support for processing the time series of satellite data and exploiting their spatio-temporal information ***,dedicated efforts are still required to develop workflows,executable on cloud-based platforms,for ingesting the satellite data,performing the targeted processes,and generating the desired *** this study,an operational workflow is proposed,based on monthly Evaporative Stress Index(ESI)anomaly,and implemented in cloud-based online Virtual Earth Laboratory(VLab)platform,as a demonstration,to monitor European agricultural water *** this end,daily time-series of actual and reference evapotranspiration(ETa and ET0),from the Spinning Enhanced Visible and Infrared Imager(SEVIRI)sensor,were used to execute the proposed workflow successfully on *** execution of the workflow resulted in obtaining one decade(2011–2020)of European monthly agricultural water stress maps at 0.04˚spatial resolution and corresponding stress reports for each *** support open science,all the workflow outputs are stored in GeoServer,documented in GeoNetwork,and made available through *** enables creating a dashboard for better visualization of the results for *** results from this study demonstrate the capability of VLab platform for water stress detection from time series of SEVIRI-ET data.

关键词： ET SEVIRI ESI water stress workflow Europe VLab demonstration

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3D U-Net Segmentation Improves Root System Reconstruction from 3D MRI Images in Automated and Manual Virtual Reality Work Flows

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Plant Phenomics 2023年第3期5卷 598-611页

作者： Tobias Selzner Jannis Horn Magdalena Landl Andreas Pohlmeier Dirk Helmrich Katrin Huber Jan Vanderborght harry vereecken Sven Behnke Andrea Schnepf Forschungszentrum Juelich GmbH Agrosphere(IBG-3)JuelichGermany Autonomous Intelligence Systems Group University of BonnBonnGermany Forschungszentrum Juelich GmbH Juelich Supercomputing CenterJuelichGermany

Magnetic resonance imaging(MRI)is used to image root systems grown in opaque ***,reconstruction of root system architecture(RSA)from 3-dimensional(3D)MRI images is *** resolution and poor contrast-to-noise ratios(CNRs)hinder automated ***,manual reconstruction is still widely ***,we evaluate a novel 2-step work flow for automated RSA *** the first step,a 3D U-Net segments MRI images into root and soil in *** the second step,an automated tracing algorithm reconstructs the root systems from the segmented *** evaluated the merits of both steps for an MRI dataset of 8 lupine root systems,by comparing the automated reconstructions to manual reconstructions of unaltered and segmented MRI images derived with a novel virtual reality *** found that the U-Net segmentation offers profound benefits in manual reconstruction:reconstruction speed was doubled(+97%)for images with low CNR and increased by 27%for images with high *** root lengths were increased by 20%and 3%,***,we propose to use U-Net segmentation as a principal image preprocessing step in manual work *** root length derived by the tracing algorithm was lower than in both manual reconstruction methods,but segmentation allowed automated processing of otherwise not readily usable MRI ***,model-based functional root traits revealed similar hydraulic behavior of automated and manual *** studies will aim to establish a hybrid work flow that utilizes automated reconstructions as scaffolds that can be manually corrected.

关键词： Root utilize otherwise

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Influences of perfluorooctanoic acid on the aggregation of multi-walled carbon nanotubes

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Journal of Environmental Sciences 2013年第3期25卷 466-472页

作者： Chengliang Li Andreas Schffer harry vereecken Marc Heggen Rong Ji Erwin Klumpp College of Resources and Environment Shandong Agricultural University National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources Biology 5-Environmental Biology and Chemodynamics RWTH Aachen University Agrosphere Institute (IBG-3) Forschungszentrum Jlich GmbH Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons Forschungszentrum Jlich State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing University Institute for Climate and Global Change Research Nanjing University

The aggregation of multi-walled carbon nanotubes （MWCNTs） in the aqueous phase not only inhibits their extensive utilization in various aspects but also dominates their environmental fate and *** role of surfactants at low concentration in the aggregation of MWCNTs has been studied,however the effect of perfluorinated surfactants at low concentration is *** understand this interfacial phenomenon,the influences of perfluorooctanoic acid （PFOA）,and sodium dodecyl sulfate （SDS） as a control,on MWCNT aggregation in the aqueous phase were examined by the UV absorbency *** of pH and cationic species on the critical coagulation concentration （CCC） value were *** CCC values were dependent on the concentration of PFOA,however a pronounced effect of SDS concentration on the CCC values was not *** CCC values of the MWCNTs were 51.6 mmol/L in NaCl and 0.28 mmol/L in CaCl 2 solutions,which suggested pronounced differences in the effects of Na＋ and Ca2＋ ions on the aggregation of the *** presence of both PFOA and SDS significantly decreased the CCC values of the MWCNTs in NaCl *** aggregation of the MWCNTs took place under acidic conditions and was not notably altered under neutral and alkaline conditions due to the electrostatic repulsion of deprotonated functional groups on the surface of the MWCNTs.

关键词： perfluorooctanoic acid aggregation multi-walled carbon nanotubes

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Development and Validation of a Deep Learning Based Automated Minirhizotron Image Analysis Pipeline

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Plant Phenomics 2022年第1期4卷 247-260页

作者： Felix Maximilian Bauer Lena Lärm Shehan Morandage Guillaume Lobet Jan Vanderborght harry vereecken Andrea Schnepf Institute of Bio-and Geosciences Agrosphere(IBG-3)Forschungszentrum Jülich GmbH52425 JülichGermany Institute of Soil Science and Land Evaluation University of Hohenheim7055978 StuttgartGermany

Root systems of crops play a significant role in *** root system is essential for water and nutrient uptake,plant stability,symbiosis with microbes,and a good soil *** have shown to be effective to noninvasively inves... 详细信息

关键词： structure crops soil

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Comparison of smoothness-constrained and geostatistically based cross-borehole electrical resistivity tomography for characterization of solute tracer plumes

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Water Science and Engineering 2016年第4期9卷 274-286页

作者： Andreas Englert Andreas Kemna Jun-feng Zhu Jan Vanderborght harry vereecken Tian-Chyi J.Yeh Institute of Geology Mineralogy and GeophysicsRuhr University Bochum Department of Geophysics Steinmann InstituteUniversity of Bonn Kentucky Geological Survey University of Kentucky Agrosphere Institute for Bio- and Geosciences(IBG-3)Forschungszentrum Jlich GmbH Department of Resources Engineering National Cheng Kung University Department of Hydrology and Water Resources The University of Arizona

Experiments using electrical resistivity tomography(ERT) have shown promising results in reducing the uncertainty of solute plume characteristics related to estimates based on the analysis of local point measurements *** explore the similarities and differences between two cross-borehole ERT inversion approaches for characterizing salt tracer plumes,namely the classical smoothness-constrained inversion and a geostatistically based approach,we performed two-dimensional synthetic *** assumptions about the solute transport model and the electrical forward and inverse model allowed us to study the sensitivity of the ERT inversion approaches towards a variety of basic conditions,including the number of boreholes,measurement schemes,contrast between the plume and background electrical conductivity,use of a priori knowledge,and point *** results show that geostatistically based and smoothness-constrained inversions of electrical resistance data yield plume characteristics of similar quality,which can be further improved when point measurements are incorporated and advantageous measurement schemes are *** expected,an increased number of boreholes included in the ERT measurement layout can highly improve the quality of inferred plume characteristics,while in this case the benefits of point conditioning and advantageous measurement schemes *** ERT inversion approaches are similarly sensitive to the noise level of the data and the contrast between the solute plume and background electrical conductivity,and robust with regard to biased input parameters,such as mean concentration,variance,and correlation length of the *** sophisticated inversion schemes have recently become available,in which flow and transport as well as electrical forward models are coupled,these schemes effectively rely on a relatively simple geometrical parameterization of the hydrogeological ***,we believe that standard uncoupled ER

关键词： Electrical resistivity tomography Inversion technique Solute tracer plume Synthetic experiment Plume characteristics

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Quantitative Multi-Layer Electromagnetic Induction Inversion and Full-Waveform Inversion of Crosshole Ground Penetrating Radar Data

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Journal of Earth Science 2015年第6期26卷 844-850页

作者： Jan van der Kruk Nils Gueting Anja Klotzsche Guowei He Sebastian Rudolph Christian von Hebel Xi Yang Lutz Weihermüller Achim Mester harry vereecken Agrosphere (IBG-3) Forschungszentrum Jülich GmbH Centre for High-Performance Scientific Computing in Terrestrial Systems (TerrSys) British Geological Survey Environmenal Science Centre Key Worth Electronic Systems (ZEA-2) Forschungszentrum Jülich GmbH

Due to the recent system developments for the electromagnetic characterization of the subsurface, fast and easy acquisition is made feasible due to the fast measurement speed, easy coupling with GPS systems, and the availability of multi-channel electromagnetic induction（EMI） and ground penetrating radar（GPR） systems. Moreover, the increasing computer power enables the use of accurate forward modeling programs in advanced inversion algorithms where no approximations are used and the full information content of the measured data can be exploited. Here, recent developments of large-scale quantitative EMI inversion and full-waveform GPR inversion are discussed that yield higher resolution of quantitative medium properties compared to conventional approaches. In both cases a detailed forward model is used in the inversion procedure that is based on Maxwell＇s equations. The multi-channel EMI data that have different sensing depths for the different source-receiver offset are calibrated using a short electrical resistivity tomography（ERT） calibration line which makes it possible to invert for electrical conductivity changes with depth over large areas. The crosshole GPR full-waveform inversion yields significant higher resolution of the permittivity and conductivity images compared to ray-based inversion results.

关键词： ground penetrating radar electromagnetic induction full-waveform inversion.

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Groundwater Geochemistry and Saltwater Intrusion in the Dakar Coastal Area, Senegal

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Journal of Geoscience and Environment Protection 2022年第12期10卷 45-64页

作者： Ousmane Coly Diouf Lutz Weihermüller Mathias Diedhiou Edgar Y. Terence Benam Beltoungou Ndeye Maguette Dieng Seynabou Cissé Faye harry vereecken Serigne Faye Geology Department Faculty of Sciences and Techniques Cheikh Anta Diop University of Dakar Dakar Senegal Forschungszentrum Jülich GmbH Agrosphere Institute IBG-3 Jülich Germany

Groundwater levels and water samples were collected from 20 drinking water pumping and piezometer wells in the urban area of Dakar coastal region in the year 2019. The pH-value, electrical conductivity, as well as calcium, magnesium, sodium, potassium, chloride, sulfate, bicarbonate, and nitrate concentrations were measured to assess the hydrochemical quality of the infrabasaltic aquifer in the area. The present work carried out a hydrochemical analysis to interpret the groundwater chemistry of the aquifer. The results of this chemical analysis indicate that Na+ > Mg2+ > Ca2+ > K+ was the most dominant cation sequence in the groundwater, while Cl- > HCO3- > SO42- > NO3- was the most dominant one for anions. The chemical analysis of our samples showed, that the Cl-Ca-Mg facies was dominant in the aquifer, while Cl-Na-K and HCO3-Na-K facies represent 20% and 10% of the groundwater sampled, respectively. A comparison of the measured groundwater quality in relation to WHO drinking water quality standards revealed that 80% of the water samples are suitable for drinking purposes. Ca enrichment, Simpson ratio, ratio of sodium chloride, and calculating Base Exchange (BEX) indices for the samples revealed that the groundwater is mainly affected by three factors: seawater intrusion due to aquifer overexploitation on one hand, and freshening processes and nitrate pollution, on the other, mainly caused by the groundwater flow from the unconfined aquifer.

关键词： Coastal Groundwater Major Ions Hydrochemical Facies Anthropogenic Activities Nitrate Pollution

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