398 research outputs found

    Anthropogenic Changes in the Landscape Hydrology of the Berlin-Brandenburg Region

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    For decades, water resources have been used intensively for drinking water, industry, agriculture and energy production. This paper summarises the main anthropogenic influences on the water cycle in a Pleistocene landscape and associated geochemical reactions. The results allow the identification and description of the main hydraulic and geochemical processes that control water and solute fluxes in different hydrological compartments, in particular recharge and discharge regions. Under progressive climate change, this process-based knowledge should be used to adapt land and water management to minimise negative impacts on hydrological resources and stabilise the regional water balance in the Berlin-Brandenburg Pleistocene landscape. Based on these results, a risk assessment approach for validation of future management strategies under changing climate conditions is presented

    Inspecting the Reliability of Geochemical Facies Identified for the Waterworks' Capture Zone in Germany

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    Little research attention has been given to validating clusters obtained from the groundwater geochemistry of the waterworks' capture zone with a prevailing lake-groundwater exchange. To address this knowledge gap, we proposed a new scheme whereby Gaussian finite mixture modeling (GFMM) and Spike-and-Slab Bayesian (SSB) algorithms were utilized to cluster the groundwater geochemistry while quantifying the probability of the resulting cluster membership against each other. We applied GFMM and SSB to 13 geochemical parameters collected during different sampling periods at 13 observation points across the Barnim Highlands plateau located in the northeast of Berlin, Germany; this included 10 observation wells, two lakes, and a gallery of drinking production wells. The cluster analysis of GFMM yielded nine clusters, either with a probability ≥0.8, while the SSB produced three hierarchical clusters with a probability of cluster membership varying from 0.8. The findings demonstrated that the clustering results of GFMM were in good agreement with the classification as per the principal component analysis and Piper diagram. By superimposing the parameter clustering onto the observation clustering, we could identify discrepancies that exist among the parameters of a certain cluster. This enables the identification of different factors that may control the geochemistry of a certain cluster, although parameters of that cluster share a strong similarity. The GFMM results have shown that from 2002, there has been active groundwater inflow from the lakes towards the capture zone. This means that it is necessary to adopt appropriate measures to reverse the inflow towards the lakes

    Efficacy of statistical algorithms in imputing missing data of streamflow discharge imparted with variegated variances and seasonalities

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    Streamflow missing data rises to a real challenge for calibration and validation of hydrological models as well as for statistically based methods of streamflow prediction. Although several algorithms have been developed thus far to impute missing values of hydro(geo)logical time series, the effectiveness of methods in imputation when the time series are influenced by different seasonalities and variances have remained largely unexplored. Therefore, we evaluated the efficacy of five different statistical algorithms in imputation of streamflow and groundwater level missing data under variegated periodicities and variances. Our performance evaluation is based on the streamflow data, procured from a hydrological model, and the observed groundwater data from the federal state of Brandenburg in Northeast Germany. Our findings revealed that imputations methods embodying the time series nature of the data (i.e., preceding value, autoregressive integrated moving average (ARIMA), and autoregressive conditional heteroscedasticity model (ARCH)) resulted in MSEs (Mean Squared Error) that are between 20 and 40 times smaller than the MSEs obtained from the Ordinary least squares (OLS) regression, which do not consider this quality. ARCH and ARIMA excelled in imputing missing values for hydrological time series, specifically for the streamflow and groundwater level data. ARCH outperformed ARIMA in both the streamflow and groundwater imputation under various conditions, such as without seasonality, with seasonality, low and high variance, and high variance (white noise) conditions. For the streamflow data, ARCH achieved average MSEs of 0.0000704 and 0.0003487 and average NSEs of 0.9957710 and 0.9965222 under without seasonality and high variance conditions, respectively. Similarly, for the groundwater level data, ARCH demonstrated its capability with average MSEs of 0.000635040 and average NSEs of 0.9971351 under GWBR1 condition. The effectiveness of ARCH, originated from econometric time series methods, should be further assessed by other hydro(geo)logical time series obtained from different climate zones

    A field study from the Oderbruch, Germany

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    The behavior of organophosphates and ethers during riverbank filtration and groundwater flow was assessed to determine their suitability as organic tracers. Four sampling campaigns were conducted at the Oderbruch polder, Germany to establish the presence of chlorinated flame retardants (TCEP, TCPP, TDCP), non-chlorinated plasticizers (TBEP, TiBP, TnBP), and hydrophilic ethers (1,4-dioxane, monoglyme, diglyme, triglyme, tetraglyme) in the Oder River, main drainage ditch, and anoxic aquifer. Selected parameters were measured in order to determine the hydro-chemical composition of both, river water and groundwater. The results of the study confirm that organophosphates (OPs) are more readily attenuated during bank filtration compared to ethers. Both in the river and the groundwater, TCPP was the most abundant OP with concentrations in the main drainage ditch ranging between 105 and 958 ng L−1. 1,4-dioxane, triglyme, and tetraglyme demonstrated persistent behavior during bank filtration and in the anoxic groundwater. In the drainage ditch concentrations of 1,4-dioxane, triglyme, and tetraglyme ranged between 1090 and 1467 ng L− 1, 37 and 149 ng L− 1, and 496 and 1403 ng L− 1, respectively. A positive correlation was found for the inorganic tracer chloride with 1,4-dioxane and tetraglyme. These results confirm the possible application of these ethers as environmental organic tracers. Both inorganic and organic compounds showed temporal variability in the surface- and groundwater. Discharge of the river water, concentrations of analytes at the time of infiltration and attenuation were identified as factors influencing the variable amounts of the analytes in the surface and groundwater. These findings are also of great importance for the production of drinking water via bank filtration and natural and artificial groundwater recharge as the physicochemical properties of ethers create challenges in their removal

    Design Guidelines For Digital Kanban Systems With High Service Level

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    One success factor of Kanban is its elegant simplicity for physical inventory control. However, especially in multi-variant productions inventory levels are digitally tracked. To maintain the high service levels of the Kanban systems, the digital representation in the ERP must reliably reflect the physical inventory levels and deviations should be detectable. The design of such a digitally tracked Kanban systems requires a booking logic and a method for deviation detection. Especially in multi-stage systems with several inventory levels, the design of a simple and robust Kanban logic is challenging. Thus, the paper first gives an overview of existing inventory booking strategies. Based on the strategies the effects of inventory deviations on logistical performance in classic Kanban and digitally controlled Kanban systems are discussed. Design guidelines summarize the analysis. Subsequently, three different design alternatives of a classical, digital and high resolution Kanban system are developed. These guidelines and design alternatives should enable practitioners to setup reliable Kanban systems including their digital representation

    North Atlantic Eddy-Driven Jet in interglacial and glacial winter climates

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    The atmospheric westerly flow in the North Atlantic (NA) sector is dominated by atmospheric waves or eddies generating via momentum flux convergence, the so-called eddy-driven jet. The position of this jet is variable and shows for the present-day winter climate three preferred latitudinal states: a northern, central, and southernposition in the NA. Here, the authors analyze the behavior of the eddy-driven jet under different glacial and interglacial boundary conditions using atmosphere–land-only simulations with the CCSM4 climate model. As state-of-the-art climate models tend to underestimate the trimodality of the jet latitude, the authors apply a bias correction and successfully extract the trimodal behavior of the jet within CCSM4. The analysis shows that during interglacial times (i.e., the early Holocene and the Eemian) the preferred jet positions are rather stable and the observed multimodality is the typical interglacial character of the jet. During glacial times, the jet is strongly enhanced, its position is shifted southward, and the trimodal behavior vanishes. This is mainly due to the presence of the Laurentide ice sheet (LIS). The LIS enhances stationary waves downstream, thereby accelerating and displacing the NA eddy-driven jet by anomalous stationary momentum flux convergence. Additionally, changes in the transient eddy activity caused by topography changes as well as other glacial boundary conditions lead to an acceleration of the westerly winds over the southern NA at the expenseof more northernareas. Consequently, bothstationaryand transient eddiesfoster the southward shift of the NA eddy-driven jet during glacial winter times

    Detecting dominant changes in irregularly sampled multivariate water quality data sets

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    Time series of groundwater and stream water quality often exhibit substantial temporal and spatial variability, whereas typical existing monitoring data sets, e.g. from environmental agencies, are usually characterized by relatively low sampling frequency and irregular sampling in space and/or time. This complicates the differentiation between anthropogenic influence and natural variability as well as the detection of changes in water quality which indicate changes in single drivers. We suggest the new term "dominant changes" for changes in multivariate water quality data which concern (1) multiple variables, (2) multiple sites and (3) long-term patterns and present an exploratory framework for the detection of such dominant changes in data sets with irregular sampling in space and time. Firstly, a non-linear dimension-reduction technique was used to summarize the dominant spatiotemporal dynamics in the multivariate water quality data set in a few components. Those were used to derive hypotheses on the dominant drivers influencing water quality. Secondly, different sampling sites were compared with respect to median component values. Thirdly, time series of the components at single sites were analysed for long-term patterns. We tested the approach with a joint stream water and groundwater data set quality consisting of 1572 samples, each comprising sixteen variables, sampled with a spatially and temporally irregular sampling scheme at 29 sites in northeast Germany from 1998 to 2009. The first four components were interpreted as (1) an agriculturally induced enhancement of the natural background level of solute concentration, (2) a redox sequence from reducing conditions in deep groundwater to post-oxic conditions in shallow groundwater and oxic conditions in stream water, (3) a mixing ratio of deep and shallow groundwater to the streamflow and (4) sporadic events of slurry application in the agricultural practice. Dominant changes were observed for the first two components. The changing intensity of the first component was interpreted as response to the temporal variability of the thickness of the unsaturated zone. A steady increase in the second component at most stream water sites pointed towards progressing depletion of the denitrification capacity of the deep aquifer

    Untersuchungen zur Resistenz von Acker-Fuchsschwanz in Baden-Württemberg und zur Wirkung von Herbiziden in Winterweizen im Hinblick auf die Vermeidung von Resistenz

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    In Verdachtsproben aus unterschiedlichen Gebieten in Baden-Württemberg konnte in den Jahren 2008 bis 2010 bei Acker-Fuchsschwanz Resistenz gegen Herbizide aus der HRAC-Gruppe A nachgewiesen werden. 2008 traten auch Biotypen mit Resistenz gegen Flupyrsulfuron (HRAC-Gruppe B) auf. 2010 wurde bei weiteren Herbiziden aus dieser Gruppe eine deutliche Wirkungsminderung festgestellt.Dieses Ergebnis spiegelte sich auch in den Ergebnissen der Feldversuche wider. Bei den Frühjahrsbehandlungen war nur mit der Variante Atlantis OD + Artus + Primus eine sehr gute Wirkung zu erzielen. Bei den anderen Varianten blieben auf einzelnen Standorten mit hohem Acker-Fuchsschwanzbesatz zu viele Ähren/m² stehen. Auf diesen Standorten sollte die Acker-Fuchsschwanzbekämpfung bevorzugt im Herbst durchgeführt werden. Mehrere Herbizidkombinationen mit Bodenherbiziden aus den HRAC-Gruppen K1/3 und F1 erzielten auch in früh gesätem Winterweizen sowohl gute Bekämpfungserfolge, als auch Mehrerträge, und waren wirtschaftlich.Stichwörter: Erträge, Frühjahrs- und Herbstanwendungen, Herbizidkombinationen, Resistenztest, Unkrautbekämpfung, WirtschaftlichkeitInvestigations into resistance in black-grass (Alopecurus myosuroides) in Baden-Württemberg and into herbicidal efficiency to reduce the risk of resistance developingSuspicious samples of black-grass seeds from fields in Baden-Württemberg were tested in the greenhouse in 2008 to 2010 for their degree of resistance. The resistance to ACCase-inhibiting herbicides was widespread. In the year 2008, black-grass plants from a few samples survived treatments with the ALS inhibitor flupyrsulfuron. In 2010, a few other ALS-inhibiting herbicides showed a reduced performance.Resistance to ALS and ACCase inhibitors occurred in the field trails too. Spring only applications of Atlantis OD + Artus + Primus provided very good levels of control. The other herbicides did not provide an acceptable level of control on some fields. There was still a high number of seed heads remaining in the field. On these fields, preemergence herbicides (HRAC groups K1/3 und F1) have a valuable role in resistance management strategy. The treatments in autumn with pre-emergence herbicides in mixture or sequence provided good control and economic surplus. Keywords: Application in spring and autumn, combinations of herbicides, economics, resistance test, weed control, yiel
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