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  • 1
    Language: English
    In: Ground Water, Nov-Dec, 2012, Vol.50, p.935(8)
    Description: To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1111/j.1745-6584.2012.00948.x/abstract Byline: Falk Handel(1), Peter Dietrich(2) Knowledge of site-specific contaminant transport processes is an essential requirement for performing various tasks concerning the protection and management of groundwater resources. However, prediction of their behavior is often difficult, especially in heterogeneous aquifers because of the lack of information about flow- and transport-governing subsurface structures and parameters. Hence, stochastic approaches have been developed and frequently used. However, extensive modeling studies on sedimentary structures have shown that consideration of hydrogeological subunits and their distribution can be essential for transport modeling. A case study from the intensely investigated Lauswiesen site is used to demonstrate that more accurate predictions are possible with improved knowledge of deterministic structures. Results of this case study using direct-push injection logging (DPIL) provide a more reliable characterization of hydraulic conductivity than sieve and flow meter data. Author Affiliation: (1)Institute for Groundwater Management, Technical University of Dresden, Bergstra[sz]e 66, D-01069 Dresden, Germany (2)Center of Applied Geoscience, University of Tubingen, Sigwartstra[sz]e 10, D-72076 Tubingen, Germany Correspondence: (*) UFZ, Helmholtz Centre for Environmental Research, Department of Monitoring and Exploration Technologies (MET), Permoserstra[sz]e 15, D-04318 Leipzig, Germany; (49) 35146342557; falk.haendel@ufz.de Received June 2011, accepted April 2012.
    Keywords: Hydrogeology -- Case Studies ; Hydrogeology -- Analysis ; Hydrogeology -- Models ; Water Resource Management -- Case Studies ; Water Resource Management -- Analysis ; Water Resource Management -- Models ; Aquifers -- Case Studies ; Aquifers -- Analysis ; Aquifers -- Models ; Groundwater -- Case Studies ; Groundwater -- Analysis ; Groundwater -- Models ; Sedimentary Structures -- Case Studies ; Sedimentary Structures -- Analysis ; Sedimentary Structures -- Models
    ISSN: 0017-467X
    Source: Cengage Learning, Inc.
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  • 2
    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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  • 3
    Language: English
    In: Environmental earth sciences, 2013, Vol.70(8), pp.3433-3446
    Description: Large thermal extractions and extensive implementation of groundwater heat pumps (GWHP) necessitate a validation of the sustainability of their use and possible detrimental effects on groundwater. The goal of this work is to develop a regional heat transport model (of ~13� km� ×� 5� km) for real site conditions. This model should consider all relevant transport processes, despite the large area under investigation. The model is based on a two-dimensional, transient-calibrated groundwater flow model for the “Leibnitzer Feld” (Styria, Austria). The two-dimensional horizontal model is linked via the FEFLOW interface manager with a newly developed “Multi-Layer-Model”-tool, which reproduces thermal aquifer–atmosphere interaction. Based on the regional heat transport model, scenarios are delineated for heating and cooling purposes for large GWHPs, which are appropriate for a small manufacturing business, an administrative building and 10 family homes. First of all, these have large spacing and thereafter, effects of area-covering usage of geothermal systems are evaluated for five administrative buildings located in close proximity to one another (200–350� m) and also for a large number of smaller heat extractions (each representing a one family house system). Modeled spatial and temporal temperature effects on the shallow aquifer are discussed. It was possible to present a simulation of realistic heating and cooling scenarios. This simulation may be introduced into practice once some further simplifications to the system are made. Locally limited heat plumes (max. length: 625� m) were observed for the manufacturing business. Any thermal effects coming from the geothermal systems were shown to be temporally stable. As such, no distinct trend of reduced annual temperatures could be observed. ; p. 3433-3446.
    Keywords: Manufacturing ; Heat Treatment ; Heat ; Temperature ; Aquifers ; Groundwater Flow ; Case Studies ; Geothermal Energy ; Groundwater ; Models ; Spatial Distribution ; Buildings ; Heat Pumps ; Business Enterprises
    ISSN: 1866-6280
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  • 4
    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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  • 5
    Language: English
    In: Environmental Earth Sciences, 2016, Vol.75(10), pp.1-8
    Description: Managed aquifer recharge has been used for various regions worldwide to improve water quantity and quality. Furthermore, contaminated site treatment often requires injection of water together with specific additives to support natural attenuation processes. Händel et al. (in J Hydrol 517:54–63, 2014. doi: 10.1016/j.jhydrol.2014.05.003 ) introduced a new recharge approach, applying cost-efficient small-diameter wells. Numerical studies were applied, among others, to investigate the effect of subsurface structures on injection process. Besides this, a comparison with an infiltration basin was made. To close the gap between the theoretical work and the practical use of this technique for medium-term injection of clean waters and to provide an experimental validation of the small-diameter well recharge, two injection tests using a small-diameter well (1″ inner diameter) were performed at the test site Pirna, Saxony, Germany. In a first short-term test, stepwise increasing injection rates were applied and showed only a slight increase in well water levels. In a second test (using the same well), groundwater was injected continuously for 14 days. The constant injection rate of 0.75 l/s resulted in a recharged water volume of 900 m 3 , showing the high-performance potential of such wells for clean water infiltration.
    Keywords: Artificial recharge ; Small-diameter wells ; Field test ; Injection
    ISSN: 1866-6280
    E-ISSN: 1866-6299
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  • 6
    Language: English
    In: Hydrogeology Journal, 2016, Vol.24(8), pp.2079-2091
    Description: An approach to establish the recharge component of managed aquifer recharge (MAR) has recently been proposed that uses small-diameter shallow wells installed using relatively inexpensive drilling methods such as direct push. As part of further development of that approach, a generalized procedure is presented for a technical and economic assessment of the approach’s potential in comparison to other systems. Following this procedure, the use of small-diameter wells was evaluated both experimentally and numerically for a site located in southern Styria, Austria. MAR is currently done at the site using a horizontal pipe infiltration system, and system expansion has been proposed with a target rate of 12 l/s using small-diameter wells as one possible option. A short-duration single-well field recharge experiment (recharge rate 1.3–3.5 l/s) was performed (recharge by gravity only). Numerical modeling of the injection test was used to estimate hydraulic conductivity ( K ). Quasi-steady-state, single-well recharge simulations for different locations, as well as a long-term transient simulation, were performed using the K value calibrated from the field injection test. Results indicate that a recharge capacity of 4.1 l/s was achievable with a maximum head rise of 0.2 m at the injection well. Finally, simulations were performed for three different well fields (4, 6 and 8 wells, respectively) designed to infiltrate a target rate of 12 l/s. The experimental and numerical assessments, supported by a cost analysis of the small-diameter wells, indicate that the small-diameter wells are a viable, cost-effective recharge approach at this and other similar sites. Une approche pour établir la composante recharge de la recharge d’aquifère sous contrôle (MAR) a été récemment proposée à l’aide des puits peu profonds de petit diamètre en utilisant des méthodes de forage relativement peu coûteuses, tels que l’enfoncement direct. Dans le cadre de la poursuite du développement de cette approche, une procédure généralisée est présentée pour une évaluation technique et économique du potentiel de l’approche par rapport aux autres systèmes. À la suite de cette procédure, l’utilisation des puits de petit diamètre a été évaluée à la fois expérimentalement et numériquement pour un site situé dans le sud de la Styrie, en Autriche. Le MAR est actuellement réalisé sur le site en utilisant un système d’infiltration horizontal à l’aide d’un tube, et l’expansion du système a été proposée avec un taux d’objectif de 12 l/s à l’aide de puits de faible diamètre comme une option possible. Une expérience de recharge de courte durée à l’aide d’un puits unique sur le terrain (taux de recharge de 1.3–3.5 l/s) a été réalisée (recharge par gravité seulement). La modélisation numérique du test d’injection a été utilisée pour estimer la conductivité hydraulique ( K ). Des simulations de recharge en puits unique en état quasi permanent pour différents endroits, ainsi qu’une simulation transitoire sur le long terme ont été effectuées en utilisant la valeur K calibrée à partir du test d’injection. Les résultats indiquent que la capacité de recharge de 4.1 l/s était réaliste avec une augmentation maximale de la charge hydraulique de 0.2 m au puits d’injection. Finalement, des simulations ont été réalisées pour trois champs de puits différents (4, 6 et 8 puits, respectivement) destinés à infiltrer un débit cible de 12 l/s. Les évaluations expérimentales et numériques, soutenues par une analyse des coûts des puits de petit diamètre, indiquent que les puits de petit diamètre constituent une approche de recharge viable et rentable pour ce site et d’autres sites similaires. Recientemente se propuso un enfoque para establecer el componente de recarga en la gestión de la recarga de acuíferos (MAR) utilizando la instalación de pozos poco profundos de pequeño diámetro con el empleo de métodos de perforación relativamente baratos, tales como el empuje directo. Como parte de un mayor desarrollo de este enfoque, se presenta un procedimiento generalizado para una evaluación técnica y económica de su potencial en comparación con otros sistemas. Siguiendo este procedimiento, se evaluó experimental y numéricamente el uso de pozos de pequeño diámetro para un sitio ubicado en el sur de Styria, Austria. El MAR se realiza actualmente en el sitio usando un sistema de cañería horizontal de infiltración, y la expansión del sistema se ha propuesto con una tasa objetivo de 12 l/s utilizando como una opción posible a pozos de pequeño diámetro. Se llevó a cabo un experimento de recarga de campo (sólo recarga por gravedad) de corta duración en un solo pozo (velocidad de recarga de 1.3–3.5 l/s). Se utilizó el modelado numérico de la prueba de inyección para estimar la conductividad hidráulica ( K ). Se llevaron a cabo simulaciones de recarga, en estado cuasi estacionario, de un solo pozo para diferentes ubicaciones, así como una simulación transitoria a largo plazo, utilizando el valor de K calibrado en la prueba de inyección de campo. Los resultados indican que la capacidad de recarga de 4.1 l/s era alcanzable con un aumento máximo de la carga hidráulica de 0.2 m en el pozo de inyección. Por último, se realizaron simulaciones para tres campos de pozos diferentes (4, 6 y 8 pozos, respectivamente) diseñados para infiltrarse con un ritmo original de 12 l/s. Las evaluaciones experimentales y numéricas, apoyados por un análisis de costos de los pozos de pequeño diámetro, indican que los pozos de pequeño diámetro son un enfoque de recarga viable y rentable en este y otros sitios similares. 近来提出了建立管理的含水层补给的补给成分方法,该方法就是使用通过相对便宜的钻探方法如直接推进法修建的小口径浅层井。作为该方法进一步发展的一部分,本文论述了与其它系统相比该方法潜力技术和经济评价方面的概化程序。然后,从实验上和数字上评估了奥地利施第里尔州南部某地小口径的利用情况。目前在研究区利用水平管渗透系统进行了管理的含水层补给,提出了系统扩充目标,即利用小口径作为一个可能的选择,目标为12升/秒。(只通过重力补给)进行了持续时间短的单井场补给实验(补给量为1.3 到3.5升/秒)。利用注水实验的数值模拟估算了水力传导率( K )。利用野外注水实验校正过的k值进行了不同地点的准稳态、单井补给模拟实验以及长期的瞬态模拟实验。结果显示,补给能力达到4.1升/秒,注入井的水头最大上升0.2 米。最后,在三个不同的井场(分别为4号、6号和8号井)进行了模拟实验,设定的目标补给量为12 升/秒。由小口径井成本分析支撑的实验和数值评价结果表明,在研究区和其它类似区小口径井是可行的、划算的补给方法。 Uma abordagem para implementação da componente recarga do gerenciamento da recarga do aquífero (GRA) foi proposto recentemente utilizando poços rasos com pequeno diâmetro, instalados usando métodos de perfuração de baixo custo. Como parte de um desenvolvimento a longo prazo dessa abordagem, um procedimento generalizado é apresentado para uma avaliação técnica e econômica do potencial dessa abordagem em comparação a outros sistemas. Seguindo esse procedimento, o uso de poços de pequeno diâmetro foi avaliado experimentalmente e numericamente em uma área localizada no Sudeste de Estíria, Áustria. GRA é atualmente realizado no local utilizando um sistema de infiltração por tubo horizontal, e uma expansão do sistema foi proposta com objetivo de alcançar uma taxa de 12 l/s usando poços de pequeno diâmetro como uma possível opção. Um experimento de campo de curta duração com um poço (taxa de recarga de 1.3–3.5 l/s) foi realizado (somente recarga por gravidade). A modelagem numérica do teste de injeção foi utilizada para estimar a condutividade hidráulica ( K ). Simulações de poços individuais em regime quase permanente, bem como simulação de longo prazo em regime transiente, foram realizadas com a calibração do valor de K através do teste de injeção a campo. Os resultados indicam que a capacidade de recarga de 4.1 l/s é alcançável com um aumento de 0.2 m da carga hidráulica no poço de injeção. Por fim, simulações foram realizadas para diferentes poços (poços 4, 6 e 8 respectivamente) destinados ao objetivo de infiltrar a uma taxa de 12 l/s. A avaliação experimental e numérica, amparada por uma análise de custo dos poços de pequeno diâmetro, indica que os mesmos são viáveis, com bom custo beneficio para a abordagem da recarga nesta área e em locais similares.
    Keywords: Austria ; Small-diameter wells ; Numerical modeling ; Managed aquifer recharge ; Field experiment
    ISSN: 1431-2174
    E-ISSN: 1435-0157
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  • 7
    In: Groundwater, November 2012, Vol.50(6), pp.935-942
    Description: Knowledge of site‐specific contaminant transport processes is an essential requirement for performing various tasks concerning the protection and management of groundwater resources. However, prediction of their behavior is often difficult, especially in heterogeneous aquifers because of the lack of information about flow‐ and transport‐governing subsurface structures and parameters. Hence, stochastic approaches have been developed and frequently used. However, extensive modeling studies on sedimentary structures have shown that consideration of hydrogeological subunits and their distribution can be essential for transport modeling. A case study from the intensely investigated Lauswiesen site is used to demonstrate that more accurate predictions are possible with improved knowledge of deterministic structures. Results of this case study using direct‐push injection logging (DPIL) provide a more reliable characterization of hydraulic conductivity than sieve and flow meter data.
    Keywords: Hydrogeology ; Environmental Geology ; Alluvium Aquifers ; Aquifers ; Baden-Wurttemberg Germany ; Central Europe ; Characterization ; Cluster Analysis ; Europe ; Experimental Studies ; Germany ; Ground Water ; Heterogeneous Materials ; Hydraulic Conductivity ; Lauswiesen Site ; Models ; Neckar River ; Permeability ; Pollutants ; Pollution ; Porous Materials ; Preferential Flow ; Pump Tests ; Statistical Analysis ; Stochastic Processes ; Transport ; Tubingen Germany ; Univariate Analysis;
    ISSN: 0017-467X
    E-ISSN: 1745-6584
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  • 8
    Language: English
    In: Grundwasser, March, 2013, Vol.18(1), p.47(7)
    Description: Byline: Prabhas Kumar Yadav (1,2), Falk Handel (1,2), Christian Muller (1), Rudolf Liedl (1), Peter Dietrich (2,3) Keywords: Natural Attenuation; Plume length; Biodegradation; Analytical solution Abstract (German): Die Verunreinigung des Grundwassers mit organischen Schadstoffen ist weltweit nach wie vor ein Problem. Fur die Auswahl einer geeigneten Sanierungsmethode ist eine Erstabschatzung des Gefahrdungspotenzials des kontaminierten Standortes unerlasslich. Dies ist unter Verwendung von analytischen und numerischen Verfahren moglich, welche Schadstoffausbreitungen prognostizieren konnen. Fur eine erste Bewertung von kontaminierten Standorten wurde das MS-Excel.sup.(c) -Werkzeug Natural-Attenuation-Fahnenlangenabschatzung, kurz "NAFLA" entwickelt. "NAFLA" ermoglicht die unkomplizierte und effiziente Berechnung und den Vergleich einiger analytischer Modelle welche fur die Abschatzung von maximalen Fahnenlangen unter stationaren Bedingungen entwickelt wurden. Diese Methoden variieren in Quellgeometrie und Modellorientierung sowie in der Modellannahme fur die (bio)chemischen Reaktionen im Modellbereich. Die Weiterentwicklung und Integration zusatzlicher analytischer Modelle ist moglich. In dieser Mitteilung wird die Entwicklung von "NAFLA" dargestellt, seine Nutzung aufgezeigt und Benutzerhinweise gegeben. Die Anwendung dieses Tools wird insbesondere in der studentischen Ausbildung, fur Behorden und Beratungsunternehmen gesehen. Abstract: Groundwater pollution with organic contaminants remains a world-wide problem. Before selection of any remediation technique, it is important to pre-assess contaminated sites with respect to their hazard. For this, several analytical and numerical approaches have been used and an initial assessment of contaminated sites the MS-Excel.sup.(c) tool "NAFLA" was developed. "NAFLA" allows a quick and straightforward calculation and comparison of some analytical approaches for the estimation of maximum plume length under steady-state conditions. These approaches differ from each other in source geometry, model domain orientation, and in the consideration of (bio)chemical reaction within the domain. In this communication, we provide details about the development of "NAFLA", its possible usage and information for users. The tool is especially designed for application in student education, by authorities and consultants. Author Affiliation: (1) Fakultat Umweltwissenschaften, Institut fur Grundwasserwirtschaft, Technische Universitat Dresden, Bergstrasse 66, 01062, Dresden, Deutschland (2) Department Monitoring- und Erkundungstechnologien, UFZ, Helmholtz-Zentrum fur Umweltforschung, Permoserstrasse 15, 04318, Leipzig, Deutschland (3) Zentrum fur Angewandte Geowissenschaften, Universitat Tubingen, Sigwartstrasse 10, 72076, Tubingen, Deutschland Article History: Registration Date: 24/09/2012 Received Date: 23/12/2011 Online Date: 20/10/2012
    Keywords: Water Pollution -- Analysis ; Groundwater -- Analysis ; Biodegradation -- Analysis
    ISSN: 1430-483X
    Source: Cengage Learning, Inc.
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  • 9
    In: Groundwater, January 2017, Vol.55(1), pp.129-135
    Description: In this article, we present a straightforward random walk model for fast evaluation of push‐pull tracer tests. By developing an adaptive algorithm, we overcome the problem of manually defining how many particles have to be used to simulate the transport problem. Beside this, we validate the random walk model by evaluating a push‐pull tracer test with drift phase and confirm the results with . The random walk model took less than 1% of computational time of , thus allowing a remarkable faster evaluation of push‐pull tracer tests. Hundred and fifty times faster assessing push‐pull tests by using a specialized model for users with commercial and scientific background.
    Keywords: Random Walk Theory ; Groundwater;
    ISSN: 0017-467X
    E-ISSN: 1745-6584
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  • 10
    Language: German
    In: Grundwasser, 2017, Vol.22(2), pp.135-142
    Description: Bei der Planung von Tracerversuchen spielen die Unsicherheiten der geohydraulischen Parameter eine erhebliche Rolle. Werden diese Unsicherheiten nicht berücksichtigt, kann das dazu führen, dass z. B. der Tracerdurchbruch verpasst wird. Eine Möglichkeit zur Berücksichtigung dieser Unsicherheiten bei der Planung ist die Ensembleprognose. Durch die beispielhafte Kopplung eines Ensembleprognosealgorithmus mit zwei kombinierten analytischen Stofftransportmodellen wird die Anwendbarkeit des Verfahrens auf geohydrologische Problemstellungen demonstriert. Dabei eignet sich der vorgestellte Algorithmus nicht nur zur Prognose (Vorwärtssimulation), sondern auch zur Parameterbestimmung (Rückwärtssimulation). Die Funktion der Parameterbestimmung kann versuchsbegleitend zu einer Verringerung der zur ursprünglichen Prognose verwendeten Unsicherheiten und damit zu einer Verbesserung selbiger eingesetzt werden. Der Algorithmus wurde in einer Software umgesetzt, welche über die Website des Instituts für Grundwasserwirtschaft der TU Dresden zur freien Verfügung heruntergeladen werden kann. While planning tracer tests, uncertainties in geohydraulic parameters should be considered as an important factor. Neglecting these uncertainties can lead to missing the tracer breakthrough, for example. One way to consider uncertainties during tracer test design is the so called ensemble forecast. The applicability of this method to geohydrological problems is demonstrated by coupling the method with two analytical solute transport models. The algorithm presented in this article is suitable for prediction as well as parameter estimation. The parameter estimation function can be used in a tracer test for reducing the uncertainties in the measured data which can improve the initial prediction. The algorithm was implemented into a software tool which is freely downloadable from the website of the Institute for Groundwater Management at TU Dresden, Germany.
    Keywords: Analytical Solution ; Tracer-Test ; Parameter Uncertainties ; Ensemble Forecast
    ISSN: 1430-483X
    E-ISSN: 1432-1165
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