@article{BoeneckeLueckRuehlmannetal.2018, author = {B{\"o}necke, Eric and L{\"u}ck, Erika and R{\"u}hlmann, J{\"o}rg and Gr{\"u}ndling, Ralf and Franko, Uwe}, title = {Determining the within-field yield variability from seasonally changing soil conditions}, series = {Precision Agriculture}, volume = {19}, journal = {Precision Agriculture}, number = {4}, publisher = {Springer}, address = {Dordrecht}, issn = {1385-2256}, doi = {10.1007/s11119-017-9556-z}, pages = {750 -- 769}, year = {2018}, abstract = {Crop yield variations are strongly influenced by the spatial and temporal availabilities of water and nitrogen in the soil during the crop growth season. To estimate the quantities and distributions of water and nitrogen within a given soil, process-oriented soil models have often been used. These models require detailed information about the soil characteristics and profile architecture (e.g., soil depth, clay content, bulk density, field capacity and wilting point), but high resolution information about these soil properties, both vertically and laterally, is difficult to obtain through conventional approaches. However, on-the-go electrical resistivity tomography (ERT) measurements of the soil and data inversion tools have recently improved the lateral resolutions of the vertically distributed measurable information. Using these techniques, nearly 19,000 virtual soil profiles with defined layer depths were successfully created for a 30 ha silty cropped soil over loamy and sandy substrates in Central Germany, which were used to initialise the CArbon and Nitrogen DYnamics (CANDY) model. The soil clay content was derived from the electrical resistivity (ER) and the collected soil samples using a simple linear regression approach (the mean R-2 of clay = 0.39). The additional required structural and hydrological properties were derived from pedotransfer functions. The modelling results, derived soil texture distributions and original ER data were compared with the spatial winter wheat yield distribution in a relatively dry year using regression and boundary line analysis. The yield variation was best explained by the simulated soil water content (R-2 = 0.18) during the grain filling and was additionally validated by the measured soil water content with a root mean square error (RMSE) of 7.5 Vol\%.}, language = {en} } @article{DomschEhlertLuecketal.2000, author = {Domsch, Horst and Ehlert, D. and L{\"u}ck, Erika and Eisenreich, Manfred}, title = {Use of the electrical conductivity to reduce the effort of precision farming}, year = {2000}, language = {en} } @article{DomschLueckEisenreich1999, author = {Domsch, Horst and L{\"u}ck, Erika and Eisenreich, Manfred}, title = {Bestimmung der elektrischen Leitf{\"a}higkeit des Bodens mit dem Meßger{\"a}t EM 38 von Geonics zur Kennzeichnung der Verteilung sich unterscheidender Bodenprofile = Determination of the electrical soil bulk conductivity with the Geonics EM 38 for the identification of the soil types distribution}, year = {1999}, language = {de} } @article{DomschLueckEisenreich1998, author = {Domsch, Horst and L{\"u}ck, Erika and Eisenreich, Manfred}, title = {Description o a soil structure by means of the penetration resistance and the electrical conductivity}, year = {1998}, language = {en} } @article{FrischbutterLueck1997, author = {Frischbutter, A. and L{\"u}ck, Erika}, title = {Eine {\"u}berarbeitete Variante zum tiefenseismischen Profil Grimma-Buckow}, year = {1997}, language = {de} } @article{GuillemoteauLueckTronicke2017, author = {Guillemoteau, Julien and L{\"u}ck, Erika and Tronicke, Jens}, title = {1D inversion of direct current data acquired with a rolling electrode system}, series = {Journal of applied geophysics}, volume = {146}, journal = {Journal of applied geophysics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0926-9851}, doi = {10.1016/j.jappgeo.2017.09.010}, pages = {167 -- 177}, year = {2017}, abstract = {Direct current systems employing a kinematic surveying strategy allow to analyze the electrical resistivity of the subsurface for large areas (i.e., several hectares). Typical applications are found in precision agriculture, archaeological prospecting and soil sciences. With the typical survey setting, the collected data sets are often characterized by a rather high level of noise and a rather coarse lateral sampling compared to data acquired with fixed electrodes. We therefore present an efficient one-dimensional inversion approach in which we put special attention on modeling the effects of noise. We apply this method to data recorded with a five-offset equatorial dipole-dipole system employing rolling electrodes. By performing several synthetic tests with realistic noise levels, we found that the considered five-configuration soundings allow for a reliable imaging of two-layer cases in the uppermost two meters of the subsurface, where the subsurface can be assumed to follow a horizontally layered geometry within 3 m around the system. By analyzing the corresponding sensitivity functions, we also show that the equatorial dipole-dipole array is relatively well suited for a 1D inversion approach compared to standard in-line electrode arrays. To illustrate this aspect, we show that our method can provide results similar to those obtained with a 2D Wenner imaging procedure for data recorded across a well-constrained 2D target. We finally apply our method to a large five-offset data set acquired in an agricultural study. The final pseudo-3D model of electrical resistivity is in accordance with borehole data available for the surveyed area. Our results demonstrate the applicability and the versatility of the presented inversion approach for large-scale data sets as they are typically collected with such rolling electrode systems. (C) 2017 Elsevier B.V. All rights reserved.}, language = {en} } @article{GuillemoteauSimonLuecketal.2016, author = {Guillemoteau, Julien and Simon, Francois-Xavier and L{\"u}ck, Erika and Tronicke, Jens}, title = {1D sequential inversion of portable multi-configuration electromagnetic induction data}, series = {Near surface geophysics}, volume = {14}, journal = {Near surface geophysics}, publisher = {Wiley-VCH}, address = {Houten}, issn = {1569-4445}, doi = {10.3997/1873-0604.2016029}, pages = {423 -- 432}, year = {2016}, abstract = {We present an algorithm that performs sequentially one-dimensional inversion of subsurface magnetic permeability and electrical conductivity by using multi-configuration electromagnetic induction sensor data. The presented method is based on the conversion of the in-phase and out-of-phase data into effective magnetic permeability and electrical conductivity of the equivalent homogeneous half-space. In the case of small-offset systems, such as portable electromagnetic induction sensors, for which in-phase and out-of-phase data are moderately coupled, the effective half-space magnetic permeability and electrical conductivity can be inverted sequentially within an iterative scheme. We test and evaluate the proposed inversion strategy using synthetic and field examples. First, we apply it to synthetic data for some highly magnetic environments. Then, the method is tested on real field data acquired in a basaltic environment to image a formation of archaeological interest. These examples demonstrate that a joint interpretation of in-phase and out-of-phase data leads to a better characterisation of the subsurface in magnetic environments such as volcanic areas.}, language = {en} } @article{HerbstKappKrummeletal.1998, author = {Herbst, R. and Kapp, Ingo and Krummel, H. and L{\"u}ck, Erika}, title = {Seismic sources for shallow investigatons : a field comparison from Northern Germany}, year = {1998}, language = {en} } @article{KrawczykLueckStiller1997, author = {Krawczyk, C. M. and L{\"u}ck, Erika and Stiller, M.}, title = {The structure of the North German Basin - the DEKORP-Experiment BASIN'96}, isbn = {90-73834-04-X}, year = {1997}, language = {en} } @article{KueblerStreichLuecketal.2017, author = {K{\"u}bler, Simon and Streich, R. and L{\"u}ck, Erika and Hoffmann, M. and Friedrich, A. M. and Strecker, Manfred}, title = {Active faulting in a populated low-strain setting (Lower Rhine Graben, Central Europe) identified by geomorphic, geophysical and geological analysis}, series = {Seismicity, fault rupture and earthquake hazards in slowly deforming regions}, volume = {432}, journal = {Seismicity, fault rupture and earthquake hazards in slowly deforming regions}, publisher = {The Geological Society}, address = {London}, isbn = {978-1-86239-745-3}, issn = {0305-8719}, doi = {10.1144/SP432.11}, pages = {127 -- 146}, year = {2017}, abstract = {The Lower Rhine Graben (Central Europe) is a prime example of a seismically active low-strain rift zone characterized by pronounced anthropogenic and climatic overprint of structures, and long recurrence intervals of large earthquakes. These factors render the identification of active faults and surface ruptures difficult. We investigated two fault scarps in the Lower Rhine Graben, to decipher their structural character, offset and potential seismogenic origin. Both scarps were modified by anthropogenic activity. The Hemmerich site lies c. 20 km SW of Cologne, along the Erft Fault. The Untermaubach site lies SW of Duren, where the Schafberg Fault projects into the Rur River valley. At the Hemmerich site, geomorphic and geophysical data, as well as exploratory coring reveal evidence of repeated normal faulting. Geophysical analysis and palaeoseismological excavation at the Untermaubach site reveal a complex fault zone in Holocene gravels characterized by subtle gravel deformation. Differentiation of tectonic and fluvial features was only possible with trenching, because fault structures and grain sizes of the sediments were below the resolution of the geophysical data. Despite these issues, our investigation demonstrates that valuable insight into past earthquakes and seismogenic deformation in a low-strain environment can be revealed using a multidisciplinary approach.}, language = {en} }