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Berlin Brandenburg

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  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 04 February 2014, Vol.111(5), pp.E531
    Description: Author contributions: J.J.B., G.C.B., A.E.B., G.L., D.O.W., and B.B.W. analyzed data and wrote the paper.
    Keywords: Agriculture ; Groundwater
    ISSN: 00278424
    E-ISSN: 1091-6490
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  • 2
    Language: English
    In: Journal of Hydrology, 19 September 2014, Vol.517, pp.54-63
    Description: Aquifer storage and recovery (ASR) methods are increasingly used to overcome the temporal imbalance between water demand and availability. Common ASR recharge methods utilize large-diameter injection wells or surface infiltration basins and trenches, and can be costly to implement. A new low-cost ASR recharge method is currently being developed. This approach is based on recharge via gravity in small-diameter wells installed with direct-push (DP) technology. Numerical modeling is used here to assess the potential of this new approach under conditions commonly faced in field settings. The primary objective is to investigate if a battery of small-diameter DP wells can serve as a viable alternative to a surface basin under typical field conditions, while the secondary objective is to assess which subsurface parameters have the greatest control on DP well performance. Simulation results indicate that gravity recharge via small-diameter wells appears to have a distinct advantage over recharge via surface infiltration basins. For example, two 0.05-m shallow vadose-zone wells with 9-m screens can recharge water at a greater rate than a 60 m basin. Also, results reveal that, contrary to an infiltration basin, the recharge rate in a DP well has a much stronger dependence on the horizontal component of hydraulic conductivity than on the vertical component. Moreover, near-surface layers of low hydraulic conductivity, which can significantly reduce the recharge capacity of a surface basin, have a relatively small impact on the recharge capacity of a well as long as a significant portion of the well screen is installed below those layers. Given that installation and operation costs can be low in comparison to common ASR recharge methods, this new approach appears to have great potential for recharging good quality water in shallow unconsolidated aquifers. A field investigation has recently been initiated to follow up the findings of this simulation assessment.
    Keywords: Aquifer Storage and Recovery ; Direct-Push ; Artificial Recharge ; Groundwater Modeling ; Geography
    ISSN: 0022-1694
    E-ISSN: 1879-2707
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  • 3
    Language: English
    In: Journal of Hydrology, Sept 19, 2014, Vol.517, p.54(10)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jhydrol.2014.05.003 Byline: Falk Handel, Gaisheng Liu, Peter Dietrich, Rudolf Liedl, James J. Butler Abstract: acents Small-diameter direct-push (DP) wells are a viable ASR recharge approach. acents Two 0.05-m shallow vadose-zone wells have a larger recharge rate than a 60m.sup.2 basin. acents Near-surface, low K-layers have a small impact on the well recharge capacity. acents DP well has a strong dependence on the horizontal component of hydraulic conductivity. Article History: Received 10 January 2014; Revised 3 May 2014; Accepted 4 May 2014 Article Note: (miscellaneous) This manuscript was handled by Peter K. Kitanidis, Editor-in-Chief, with the assistance of Ty Ferre, Associate Editor
    Keywords: Hydrogeology -- Analysis
    ISSN: 0022-1694
    Source: Cengage Learning, Inc.
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  • 4
    In: Geophysical Research Letters, 16 November 2014, Vol.41(21), pp.7560-7565
    Description: Successful prediction of groundwater flow and solute transport through highly heterogeneous aquifers has remained elusive due to the limitations of methods to characterize hydraulic conductivity () and generate realistic stochastic fields from such data. As a result, many studies have suggested that the classical advective‐dispersive equation (ADE) cannot reproduce such transport behavior. Here we demonstrate that when high‐resolution data are used with a fractal stochastic method that produces fields with adequate connectivity, the classical ADE can accurately predict solute transport at the macrodispersion experiment site in Mississippi. This development provides great promise to accurately predict contaminant plume migration, design more effective remediation schemes, and reduce environmental risks. Non‐Gaussian transport behavior at the MADE site is unraveledADE can reproduce tracer transport in heterogeneous aquifers with no calibrationNew fractal method generates heterogeneous K fields with adequate connectivity
    Keywords: Made Site ; Fractal Method ; Non‐Gaussian Transport ; Advective‐Dispersive Equation ; Hydraulic Conductivity ; Aquifer Characterization
    ISSN: 0094-8276
    E-ISSN: 1944-8007
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  • 5
    In: Groundwater, May 2016, Vol.54(3), pp.425-433
    Description: Aquifer storage and recovery () is the artificial recharge and temporary storage of water in an aquifer when water is abundant, and recovery of all or a portion of that water when it is needed. One key limiting factor that still hinders the effectiveness of is the high costs of constructing, maintaining, and operating the artificial recharge systems. Here we investigate a new recharge method for in near‐surface unconsolidated aquifers that uses small‐diameter, low‐cost wells installed with direct‐push () technology. The effectiveness of a well for recharge is compared with that of a surface infiltration basin at a field site in north‐central Kansas. The performance of the surface basin was poor at the site due to the presence of a shallow continuous clay layer, identified with profiling methods, that constrained the downward movement of infiltrated water and significantly reduced the basin recharge capacity. The well penetrated through this clay layer and was able to recharge water by gravity alone at a much higher rate. Most importantly, the costs of the well, including both the construction and land costs, were only a small fraction of those for the infiltration basin. This low‐cost approach could significantly expand the applicability of as a water resources management tool to entities with limited fiscal resources, such as many small municipalities and rural communities. The results of this investigation demonstrate the great potential of wells as a new recharge option for projects in near‐surface unconsolidated aquifers.
    Keywords: Aquifers – Investigations;
    ISSN: 0017-467X
    E-ISSN: 1745-6584
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  • 6
    Language: English
    In: Grundwasser, 2012, Vol.17(1), pp.19-29
    Description: Spatial variations in hydraulic conductivity (K) are a primary control on contaminant movement in groundwater, but characterization of these variations has proven difficult. Over the last two decades, significant progress has been made in utilizing Direct Push (DP) technology to characterize K variations in unconsolidated settings. Profiling methods have been developed based on empirical correlations between K and more readily evaluated formation properties and on the formation response to water injection or extraction. The latter (hydraulic) methods appear to have the most potential. Initial work on these methods involved adaptation of conventional well tests, but recent efforts have better exploited DP capabilities. The High-Resolution K and continuous Direct Push Injection Logger (DPIL) methods are the most promising approaches. Both provide high-resolution (0.015 m) K profiles, although the DPIL profile is only qualitative in nature. Currently, the K range of both is approximately 0.001 to 60 m/d, but that range should increase in the near future. Die räumliche Verteilung der hydraulischen Durchlässigkeit (K) bestimmt maßgeblich den Schadstofftransport im Grundwasser, lässt sich aber durch Messungen nur schwer erfassen. In den letzten zwei Jahrzehnten gab es jedoch mit dem Einsatz von Direct Push (DP) deutliche Fortschritte, um Verteilungen von K in unverfestigten Sedimenten zu ermitteln. So wurden Methoden zu ihrer Erfassung entwickelt, die auf empirischen Beziehungen zwischen K und einfach zu ermittelnden Untergrundeigenschaften beruhen und solche, für die Wasserinjektions- oder Extraktionsversuche genutzt werden, wobei letztere am erfolgversprechendsten sind. Ursprüngliche Ansätze beruhen dabei auf der Durchführung von konventionellen Versuchen mit DP-Ausrüstung. Neuere Entwicklungen erlauben es aber, die Möglichkeiten von DP besser auszunutzen, von denen das ,,High Resolution K“ und kontinuierliche ,,DP Injection Logging“ dabei die am erfolgversprechendsten sind. Beide Methoden erlauben hochauflösend K-Profile (0,015 m) in einem Anwendungsbereich zwischen ca. 0,001 und 60 m/d zu ermitteln. Zukünftig ist zu erwarten, dass dieser Bereich mit neuen Geräteentwicklungen und Verfahren sich erweitern wird.
    Keywords: Hydraulic conductivity ; Direct Push, High resolution profiling ; Site characterization
    ISSN: 1430-483X
    E-ISSN: 1432-1165
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  • 7
    In: Groundwater, July 2019, Vol.57(4), pp.562-574
    Description: Direct push injection logging (DPIL) has become one of the most widely used approaches for obtaining vertical profiles of hydraulic conductivity () in environmental site investigations. Despite its widespread use, however, there has been no rigorous analysis of the underlying physical processes that take place during DPIL or how the approach would perform under different hydrogeological and operating conditions. We address these issues through a series of numerical simulations. Results show that the ratio of DPIL injection rate over pressure can be used for direct determination of when is 〉10 m/s. When is 10/m, the ratio becomes increasingly sensitive to Ss; in that case, additional information on Ss is needed for reliable estimation. For unconsolidated formations of moderate or higher, the ratio of injection rate over pressure should provide a reasonable estimate when is 〈10/m. Although water injection at previous depths during continuous DPIL has only a small impact on the pressure response measured at the current injection depth, probe advancement can have a significant impact when and Ss are small. Consequently, in fine‐grained materials, the advancement‐generated pore water pressure increase can comprise a large portion of the measured pressure response. To diminish the impact of probe advancement in such materials, advancement speed should be kept as low as possible (e.g., 0.5 cm/s). : This work sheds light on direct push injection logging and provides valuable guidance on its use for environmental site investigation.
    Keywords: Aquifers – Analysis ; Logging – Analysis;
    ISSN: 0017-467X
    E-ISSN: 1745-6584
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  • 8
    In: Water Resources Research, November 2016, Vol.52(11), pp.8970-8985
    Description: In earlier work, we presented a geostatistical assessment of high‐resolution hydraulic conductivity () profiles obtained at the MADE site using direct‐push (DP) methods. The profiles are derived from direct‐push injection logger (DPIL) measurements that provide a relative indicator of vertical variations in with a sample spacing of 1.5 cm. The DPIL profiles are converted to profiles by calibrating to the results of direct‐push permeameter (DPP) tests performed at selected depths in some of the profiles. Our original calibration used a linear transform that failed to adequately account for an upper limit on DPIL responses in high‐ zones and noise in the DPIL data. Here we present a revised calibration procedure that accounts for the upper limit and noise, leading to DPIL values that display a somewhat different univariate distribution and a lower ln variance (5.9 ± 1.5) than the original calibration values (6.9 ± 1.8), although each variance estimate falls within the other's 95% confidence interval. Despite the change in the univariate distribution, the autocorrelation structure and large‐scale patterns exhibited by the revised DPIL values still agree well with those exhibited by the flowmeter data from the site. We provide the DPIL and DPP data, along with our calibrated DPIL values, in the Supporting Information. Revised calibration of MADE direct‐push data better reflects tool behavior Revisions improve representation of high hydraulic conductivity zones Autocorrelation structure and large‐scale patterns change little
    Keywords: Aquifer Characterization ; Direct‐Push
    ISSN: 0043-1397
    E-ISSN: 1944-7973
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  • 9
    Language: English
    In: Theoretical and Applied Genetics, 2011, Vol.122(2), pp.341-353
    Description: SHZ-2 is an indica rice cultivar that exhibits broad-spectrum resistance to rice blast; it is widely used as a resistance donor in breeding programs. To dissect the QTL responsible for broad-spectrum blast resistance, we crossed SHZ-2 to TXZ-13, a blast susceptible indica variety, to produce 244 BC 4 F 3 lines. These lines were evaluated for blast resistance in greenhouse and field conditions. Chromosomal introgressions from SHZ-2 into the TXZ-13 genome were identified using a single feature polymorphism microarray, SSR markers and gene-specific primers. Segregation analysis of the BC 4 F 3 population indicated that three regions on chromosomes 2, 6, and 9, designated as qBR2.1 , qBR6.1 , and qBR9.1 , respectively, was associated with blast resistance and contributed 16.2, 14.9, and 22.3%, respectively, to the phenotypic variance of diseased leaf area (DLA). We further narrowed the three QTL regions using pairs of sister lines extracted from heterogeneous inbred families (HIF). Pairwise comparison of these lines enabled the determination of the relative contributions of individual QTL. The qBR9.1 conferred strong resistance, whereas qBR2.1 or qBR6.1 individually did not reduce disease under field conditions. However, when qBR2.1 and qBR6.1 were combined, they reduced disease by 19.5%, suggesting that small effect QTLs contribute to reduction of epidemics. The qBR6.1 and qBR9.1 regions contain nucleotide-binding sites and leucine rich repeats (NBS-LRR) sequences, whereas the qBR2.1 did not. In the qBR6.1 region, the patterns of expression of adjacent NBS-LRR genes were consistent in backcross generations and correlated with blast resistance, supporting the hypothesis that multiple resistance genes within a QTL region can contribute to non-race-specific quantitative resistance.
    Keywords: Atmospheric Carbon Dioxide ; Explosions ; Epidemics ; Rice ; Plant Genetics ; Quantitative Genetics;
    ISSN: 0040-5752
    E-ISSN: 1432-2242
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  • 10
    In: Water Resources Research, May 2011, Vol.47(5), pp.n/a-n/a
    Description: This study investigates connectivity in a small portion of the extremely heterogeneous aquifer at the Macrodispersion Experiment (MADE) site in Columbus, Mississippi. A total of 19 fully penetrating soil cores were collected from a rectangular grid of 4 m by 4 m. Detailed grain size analysis was performed on 5 cm segments of each core, yielding 1740 hydraulic conductivity () estimates. Three different geostatistical simulation methods were used to generate 3‐D conditional realizations of the field for the sampled block. Particle tracking calculations showed that the fastest particles, as represented by the first 5% to arrive, converge along preferential flow paths and exit the model domain within preferred areas. These 5% fastest flow paths accounted for about 40% of the flow. The distribution of preferential flow paths and particle exit locations is clearly influenced by the occurrence of clusters formed by interconnected cells with equal to or greater than the 0.9 decile of the data distribution (10% of the volume). The fraction of particle paths within the high‐ clusters ranges from 43% to 69%. In variogram‐based fields, some of the fastest paths are through media with lower values, suggesting that transport connectivity may not require fully connected zones of relatively homogenous . The high degree of flow and transport connectivity was confirmed by the values of two groups of connectivity indicators. In particular, the ratio between effective and geometric mean (on average, about 2) and the ratio between the average arrival time and the arrival time of the fastest particles (on average, about 9) are consistent with flow and advective transport behavior characterized by channeling along preferential flow paths. We present a very valuable data set We prove the high degree of flow and transport connectivity at the MADE site We show that significant transport connectivity may not require a connected zone
    Keywords: Connectivity ; Preferential Flow Paths ; Heterogeneous Media ; Made Site ; Geostatistical Simulation
    ISSN: 0043-1397
    E-ISSN: 1944-7973
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