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Статті в журналах з теми "Groundwater contribution"

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Lam, A., D. Karssenberg, B. J. J. M. van den Hurk, and M. F. P. Bierkens. "Spatial and temporal connections in groundwater contribution to evaporation." Hydrology and Earth System Sciences Discussions 8, no. 1 (February 1, 2011): 1541–68. http://dx.doi.org/10.5194/hessd-8-1541-2011.

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Abstract. In climate models, lateral terrestrial water fluxes are usually neglected. We estimated the contribution of vertical and lateral groundwater fluxes to the land surface water budget at a subcontinental scale, by modelling convergence of groundwater and surfacewater fluxes. We present a hydrological model of the entire Danube Basin at 5 km resolution, and use it to show the importance of groundwater for the surface climate. The contribution of groundwater to evaporation is significant, and can be upwards of 30% in summer. We show that this contribution is local by presenting the groundwater travel times and the magnitude of groundwater convergence. Throughout the Danube Basin the lateral fluxes of groundwater are negligible when modelling at this scale and resolution. Also, it is shown that the contribution of groundwater to evaporation has important temporal characteristics. An experiment with the same model shows that a wet episode influences groundwaters contribution to summer evaporation for several years afterwards. This indicates that modelling groundwater flow has the potential to augment the multi-year memory of climate models.
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Bidwell, V. J., R. Stenger, and G. F. Barkle. "Dynamic analysis of groundwater discharge and partial-area contribution to Pukemanga Stream, New Zealand." Hydrology and Earth System Sciences Discussions 4, no. 4 (July 30, 2007): 2461–96. http://dx.doi.org/10.5194/hessd-4-2461-2007.

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Abstract. The proportion and origin of groundwater contribution to streamflow from agricultural catchments is relevant to estimation of the effects of nitrate leached from the soil on the quality of surface waters. This study addresses the partitioning of streamflow contributions from near-surface runoff and from groundwater, each with different contributing land area, on a steep pastoral hillslope in a humid climate. The 3 ha headwater catchment of the perennial Pukemanga Stream, in the North Island of New Zealand, was instrumented for continuous observation of climatic data, streamflow and groundwater level. The dynamics of groundwater levels and groundwater contribution to streamflow were analysed by means of a one-parameter, eigenvalue-eigenfunction description of a 1-D aquifer model. Model results for seven years of daily data predict that 36–44% of the topographical catchment contributes groundwater to the stream. The remaining groundwater generated within the catchment contributes to streamflow outside the catchment. After correction for contributing areas, groundwater was calculated to be 58–83% of observed annual catchment streamflow or 78–93% of flow generation on a unit area basis. Concurrent hourly data for streamflow and groundwater levels at two sites indicate the dynamic behaviour of a local groundwater system. Groundwater flow dynamics that support the perennial nature of this headwater stream are consistent with the size of the groundwater body, porosity of the subsurface material, and hydraulic conductivity derived from partitioning of streamflow contributions.
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Bidwell, V. J., R. Stenger, and G. F. Barkle. "Dynamic analysis of groundwater discharge and partial-area contribution to Pukemanga Stream, New Zealand." Hydrology and Earth System Sciences 12, no. 4 (July 28, 2008): 975–87. http://dx.doi.org/10.5194/hess-12-975-2008.

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Abstract. The proportion and origin of groundwater contribution to streamflow from agricultural catchments is relevant to estimation of the effects of nitrate leached from the soil on the quality of surface waters. This study addresses the partitioning of streamflow contributions from near-surface runoff and from groundwater, each with different contributing land area, on a steep pastoral hillslope in a humid climate. The 3 ha headwater catchment of the perennial Pukemanga Stream, in the North Island of New Zealand, was instrumented for continuous observation of climatic data, streamflow and groundwater level. The dynamics of groundwater levels and groundwater contribution to streamflow were analysed by means of a one-parameter, eigenvalue-eigenfunction description of a 1-D aquifer model. Model results for seven years of daily data predict that 36–44% of the topographical catchment contributes groundwater to the stream. The remaining groundwater generated within the catchment contributes to streamflow outside the catchment. Groundwater was calculated to be 58–83% of observed annual streamflow from the topographical catchment. When the smaller groundwater catchment is taken into account, the groundwater contribution to streamflow is 78–93% on a unit area basis. Concurrent hourly data for streamflow and groundwater levels at two sites indicate the dynamic behaviour of a local groundwater system. Groundwater flow dynamics that support the perennial nature of this headwater stream are consistent with the size of the groundwater body, porosity of the subsurface material, and hydraulic conductivity derived from partitioning of streamflow contributions.
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Zhu, Yonghua, Liliang Ren, Robert Horton, Haishen Lü, Xi Chen, Yangwen Jia, Zhenlong Wang, and E. A. Sudicky. "Estimating the contribution of groundwater to rootzone soil moisture." Hydrology Research 44, no. 6 (January 16, 2013): 1102–13. http://dx.doi.org/10.2166/nh.2013.071.

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In the Huaibei Plain basin, China, soybean is a main crop. During the soybean growth period, rainfall can vary largely and depth to watertable can also vary largely. The amount of water supplied to the soybean rootzone by groundwater affects soybean growth and yield. Accurate simulation of groundwater contributions to soybean rootzone soil moisture (groundwater contribution) can be important for determining irrigation to and drainage from soybean fields. Based on field observations and local weather data of 2005, HYDRUS-1D was validated by comparing simulated and measured rootzone soil water contents. The validated model was used to estimate the daily groundwater contributions for three different soybean hydrological growing seasons, i.e., an average year (1997), a wet year (2005), and a dry year (2004) with soybean growth at its optimal state. The main results were: (1) seasonal groundwater contribution was 157 mm in the experimental field, and the estimated groundwater contributions were 158, 222, and 387 mm in the wet, average, and dry seasons, respectively; (2) the groundwater contribution was about 63% of the total seasonal transpiration in the experimental field, and those were about 142, 80, and 66% of the total seasonal transpiration in dry, average, and wet seasons, respectively.
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Lam, A., D. Karssenberg, B. J. J. M. van den Hurk, and M. F. P. Bierkens. "Spatial and temporal connections in groundwater contribution to evaporation." Hydrology and Earth System Sciences 15, no. 8 (August 24, 2011): 2621–30. http://dx.doi.org/10.5194/hess-15-2621-2011.

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Abstract. In climate models, lateral terrestrial water fluxes are usually neglected. We estimated the contribution of vertical and lateral groundwater fluxes to the land surface water budget at a subcontinental scale, by modeling convergence of groundwater and surfacewater fluxes. We present a hydrological model of the entire Danube Basin at 5 km resolution, and use it to show the importance of groundwater for the surface climate. Results show that the contribution of groundwater to evaporation is significant, and can locally be higher than 30 % in summer. We demonstrate through the same model that this contribution also has important temporal characteristics. A wet episode can influence groundwater contribution to summer evaporation for several years afterwards. This indicates that modeling groundwater flow has the potential to augment the multi-year memory of climate models. We also show that the groundwater contribution to evaporation is local by presenting the groundwater travel times and the magnitude of groundwater convergence. Throughout the Danube Basin the lateral fluxes of groundwater are negligible when modeling at this scale and resolution. This suggests that groundwater can be adequately added in land surface models by including a lower closed groundwater reservoir of sufficient size with two-way interaction with surface water and the overlying soil layers.
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6

Abbas, Haider, and Ramanathan Sri Ranjan. "Groundwater contribution to irrigated potato production in the Canadian Prairies." Canadian Biosystems Engineering 57, no. 1 (August 10, 2015): 1.13–1.24. http://dx.doi.org/10.7451/cbe.2015.57.1.13.

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Fan, Y., and G. Miguez-Macho. "Potential groundwater contribution to Amazon evapotranspiration." Hydrology and Earth System Sciences Discussions 7, no. 4 (July 30, 2010): 5131–70. http://dx.doi.org/10.5194/hessd-7-5131-2010.

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Abstract. Climate and land ecosystem models simulate a dry-season vegetation stress in the Amazon forest, but observations show enhanced growth in response to higher radiation under less cloudy skies, indicating an adequate water supply. Proposed mechanisms include larger soil water store and deeper roots in nature and the ability of roots to move water up and down (hydraulic redistribution). Here we assess the importance of the upward soil water flux from the groundwater driven by capillarity. We present a map of water table depth from observations and groundwater modeling, and a map of potential capillary flux these water table depths can sustain. The maps show that the water table beneath the Amazon can be quite shallow in lowlands and river valleys (<5 m in 36% and <10 m in 60% of Amazonia). The water table can potentially sustain a capillary flux of >2.1 mm day−1 to the land surface averaged over Amazonia, but varies from 0.6 to 3.7 mm day−1 across nine study sites. Current models simulate a large-scale reduction in dry-season photosynthesis under today's climate and a possible dieback under projected future climate with a longer dry season, converting the Amazon from a net carbon sink to a source and accelerating warming. The inclusion of groundwater and capillary flux may modify the model results.
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Fan, Y., and G. Miguez-Macho. "Potential groundwater contribution to Amazon evapotranspiration." Hydrology and Earth System Sciences 14, no. 10 (October 25, 2010): 2039–56. http://dx.doi.org/10.5194/hess-14-2039-2010.

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Abstract. Climate and land ecosystem models simulate a dry-season vegetation stress in the Amazon forest, but observations do not support these results, indicating adequate water supply. Proposed mechanisms include larger soil water store and deeper roots in nature and the ability of roots to move water up and down (hydraulic redistribution), both absent in the models. Here we provide a first-order assessment of the potential importance of the upward soil water flux from the groundwater driven by capillarity. We present a map of equilibrium water table depth from available observations and a groundwater model simulation constrained by these observations. We then present a map of maximum capillary flux these water table depths, combined with the fine-textured soils in the Amazon, can potentially support. The maps show that the water table beneath the Amazon can be shallow in lowlands and river valleys (<5 m in 36% and <10 m in 60% of Amazonia). These water table depths can potentially accommodate a maximum capillary flux of 2.1 mm day−1 to the land surface averaged over Amazonia, but varies from 0.6 to 3.7 mm day−1 across nine study sites. We note that the results presented here are based on limited observations and simple equilibrium model calculations, and as such, have important limitations and must be interpreted accordingly. The potential capillary fluxes are not indicative of their contribution to the actual evapotranspiration, and they are only an assessment of the possible rate at which this flux can occur, to illustrate the power of soil capillary force acting on a shallow water table in fine textured soils. They may over-estimate the actual flux where the surface soils remain moist. Their contribution to the actual evapotranspiration can only be assessed through fully coupled model simulation of the dynamic feedbacks between soil water and groundwater with sub-daily climate forcing. The equilibrium water table obtained here serves as the initial state for the dynamic simulation, and together with the equilibrium potential capillary flux, will serve as a baseline to evaluate the diurnal, event, seasonal and inter-annual dynamics.
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Mustafa, Syed M. Touhidul, M. Moudud Hasan, Ajoy Kumar Saha, Rahena Parvin Rannu, Els Van Uytven, Patrick Willems, and Marijke Huysmans. "Multi-model approach to quantify groundwater-level prediction uncertainty using an ensemble of global climate models and multiple abstraction scenarios." Hydrology and Earth System Sciences 23, no. 5 (May 13, 2019): 2279–303. http://dx.doi.org/10.5194/hess-23-2279-2019.

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Abstract. Worldwide, groundwater resources are under a constant threat of overexploitation and pollution due to anthropogenic and climatic pressures. For sustainable management and policy making a reliable prediction of groundwater levels for different future scenarios is necessary. Uncertainties are present in these groundwater-level predictions and originate from greenhouse gas scenarios, climate models, conceptual hydro(geo)logical models (CHMs) and groundwater abstraction scenarios. The aim of this study is to quantify the individual uncertainty contributions using an ensemble of 2 greenhouse gas scenarios (representative concentration pathways 4.5 and 8.5), 22 global climate models, 15 alternative CHMs and 5 groundwater abstraction scenarios. This multi-model ensemble approach was applied to a drought-prone study area in Bangladesh. Findings of this study, firstly, point to the strong dependence of the groundwater levels on the CHMs considered. All groundwater abstraction scenarios showed a significant decrease in groundwater levels. If the current groundwater abstraction trend continues, the groundwater level is predicted to decline about 5 to 6 times faster for the future period 2026–2047 compared to the baseline period (1985–2006). Even with a 30 % lower groundwater abstraction rate, the mean monthly groundwater level would decrease by up to 14 m in the southwestern part of the study area. The groundwater abstraction in the northwestern part of Bangladesh has to decrease by 60 % of the current abstraction to ensure sustainable use of groundwater. Finally, the difference in abstraction scenarios was identified as the dominant uncertainty source. CHM uncertainty contributed about 23 % of total uncertainty. The alternative CHM uncertainty contribution is higher than the recharge scenario uncertainty contribution, including the greenhouse gas scenario and climate model uncertainty contributions. It is recommended that future groundwater-level prediction studies should use multi-model and multiple climate and abstraction scenarios.
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Listyani, T., and I. A. Prabowo. "Groundwater in Bener area, its quality and contribution for agriculture." IOP Conference Series: Earth and Environmental Science 985, no. 1 (February 1, 2022): 012028. http://dx.doi.org/10.1088/1755-1315/985/1/012028.

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Abstract The existence of surface water is not always sufficient for the needs of the community, also for agricultural needs. Therefore, groundwater can be an alternative water supply in the irrigation system, so it is necessary to assess its quality. Groundwater quality is the result of the interaction of material (soil/rock), the type of flow/transport and the change processes. The results of these components produce different groundwater quality in each region. To assess the groundwater quality in Bener and its surrounding areas, this research was carried out by direct survey in the field and testing the physical/chemical properties of groundwater in the laboratory. Groundwater sampling was carried out at 6 dug wells and 2 springs. The analysis shows that all samples are bicarbonate groundwater types, with variations of Na+, Ca2+ and Mg2+ dominant cations. Groundwater quality shows a pH value of 6.2 - 6.7, TDS of 45 - 306 ppm, hardness of 39.73 - 200.43 ppm, SAR (Sodium Adsorption Ratio) of 12.12 - 76.64, Na% of 19.81 - 62.11, and RSC (Residual Sodium Carbonate) of 0.04 - 1.35. According to its quality, groundwater can be used to support irrigation for agriculture in the area.
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Дисертації з теми "Groundwater contribution"

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Pacheco, Adriana. "Contribution of methanotrophic groundwater and rhizosphere bacteria to phytoremediation." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0013836.

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Burkett, Danny, and danny burkett@deakin edu au. "Nutrient contribution to hyper-eutrophic wetlands in Perth, Western Australia." Deakin University. School of Life and Environmental Sciences, 2005. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20071115.082506.

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This thesis investigates nutrient contribution to six hyper-eutrophic lakes located within close proximity of each other on the Swan Coastal Plain and 20 kilometres south of the Perth Central Business District, Western Australia. The lakes are located within a mixed land use setting and are under the management of a number of state and local government departments and organisations. These are a number of other lakes on the Swan Coastal Plain for which the majority are less than 3 metres in depth and considered as an expression of the groundwater as their base is below the regional groundwater table throughout most of the year. The limited amount of water quality data available for these six lakes and the surface water and groundwater flowing into them has restricted a thorough understanding of the processes influencing the water quality of the lakes. Various private and public companies and organisations have undertaken studies on some of the individual wetlands and there is a wide difference in scientific opinion as to the major source of the nutrients to those wetlands. These previous studies failed to consider regional surface water and groundwater effects on the nutrient fluxes and they predominantly only investigated single wetland systems. This study attempts for the first time to investigate the regional contribution of nutrients to this system of wetlands existing on the Swan Coastal plain. As such, it also includes new research on the nutrient contribution to some of the remaining wetlands. The research findings indicate that the lake sediments represent a considerable store of nutrients (nitrogen and phosphorus). These sediments in turn control the nutrient status of the lake's water column. Surface water is found to contribute on an event-basis load of nutrients to the lakes whilst the groundwater surprisingly appears to contribute a comparatively low input of nutrients but governs the water depth. Analysis of the regional groundwater shows efficient denitrifying abilities as a result of denitrifying bacteria and the transport is localised. Management recommendations for the remediation of the social and environmental value of the lakes include treatment of the lake’s sediments via chemical bonding or atmospheric oxidation; utilising the regional groundwater’s denitrifying abilities to ‘treat’ the surface water via infiltration basins; and investigating the merits of managed or artificial aquifer recharge (MAR).
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Chatton, Eliot. "Contribution of dissolved gases to the understanding of groundwater hydrobiogeochemical dynamics." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S131/document.

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Depuis plus d’un siècle, les changements globaux sont à l’origine de profondes modifications de nos sociétés, nos modes de vie et il en va bien sûr de même pour notre environnement. Cette trajectoire empruntée, bon gré mal gré, par l’ensemble de l’humanité n’est pas sans conséquences pour les systèmes naturels et semble déjà mener les générations futures au-devant de grands défis. Afin de ne pas compromettre notre capacité à relever ces épreuves futures et, devant l’urgence du besoin d’action, une partie de la communauté scientifique a choisi de concentrer ses efforts sur la couche superficielle de notre planète qui soutient la vie terrestre : la Zone Critique. L’émergence de ce concept souligne la nécessité de développer des approches scientifiques pluridisciplinaires intégrant une large variété d’échelles de temps et d’espace. En tant que lien entre les différents compartiments de la Zone Critique (Atmosphère, Biosphère, Hydrosphère, Lithosphère et Pédosphère), l’eau est une molécule essentielle aux échanges d’énergie et de matière dont la dynamique requiert une attention particulière. Compte tenu de la diversité et de la variabilité spatiotemporelle des transferts d’eau et de matière dissoute dans les milieux aquatiques, de nouvelles méthodes d'investigations sont nécessaires. L'objectif général de cette thèse est de décrire l’intérêt et le potentiel qui résident dans l’utilisation des gaz dissous, en particulier lorsqu’ils sont mesurés à haute fréquence sur le terrain, afin de caractériser la dynamique hydrobiogéochimique des eaux naturelles de la Zone Critique à différentes échelles spatiales et temporelles. Pour parfaire cette ambition, ce travail s’est tout d’abord attaché au développement d'une instrumentation innovante puis, à la mise en place de nouveaux traceurs intégrés dans des dispositifs expérimentaux originaux et enfin, à l'acquisition, au traitement et à l'analyse de différents jeux de données de gaz dissous en se focalisant sur les eaux souterraines
For more than a century, global change has led to a profound modification of our societies, our lifestyles and, of course, our environment. This trajectory followed willy-nilly by all mankind has consequences for natural systems and already seems to lead the future generations ahead of serious challenges. In order not to compromise our ability to meet these future ordeals, and because of the urgent need for action, part of the scientific community has chosen to concentrate on the near-surface environment that supports terrestrial life: the Critical Zone. The emergence of this concept underlines the need to develop multidisciplinary scientific approaches integrating a wide variety of temporal and spatial scales. As the link between the different compartments of the Critical Zone (Atmosphere, Biosphere, Hydrosphere, Lithosphere and Pedosphere), water is an essential molecule controlling the exchanges of energy and matter whose dynamics require special attention. In view of the diversity and spatiotemporal variability of water and matter transfers arising in aquatic environments, new methods of investigation are needed. The general objective of this thesis is to describe the interest and the potential lying in the use of dissolved gases, especially when they are measured at high frequency in the field, in order to characterise the hydrobiogeochemical dynamics of the natural waters of the Critical Zone at different spatial and temporal scales. To perfect this ambition, this work focused first on the development of an innovative instrumentation, then, on the implementation of novel tracers integrated into original experimental setups and finally, on the acquisition, processing and analysis of different dissolved gas datasets focusing on groundwater
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Liuzzo, Scorpo Alberto. "Heat transfer in borehole heat exchangers and the contribution of groundwater flow." Doctoral thesis, Università degli studi di Trieste, 2014. http://hdl.handle.net/10077/10123.

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2012/2013
The exploitation of geothermal heat by ground source heat pumps is presently growing throughout Europe and the world. In Italy, at the end of 2010, borehole heat exchangers covered most of the 30% of the total energy used for space conditioning, showing an increase of 50%compared to 2005. The forecasts for 2015 suggest a further increase in the direct uses of the geothermal heat exceeding 50% compared to 2010 and a corresponding increase in the geothermal energy consumption. The possibility to design plants with higher efficiency and lower costs of installation and operation is required, to support the growth of the ground source heat pump systems and the consequent diffusion of the exploitation of the geothermal resources. Research and better knowledge of the processes involved in the heat transfer between the borehole heat exchanger and the surrounding ground is crucial to predict the behavior of the plant-geothermal source interaction in any possible operational condition. The knowledge of the hydrogeological characteristics of the specific site where the plant has to be installed is also essential to prevent over- or under-sizing of the heat exchanger(s) due to a rough design. Over the years, several analytical solutions have been proposed to calculate the temperature distribution around a borehole heat exchanger during operation. The infinite line source analytical model considers an infinite linear heat source which exchanges heat with the surrounding ground by conduction only. Other models, based on the infinite linear heat source, have been later developed, considering also the contribution to the conductive heat transfer due to groundwater flow. The presence of flowing water around a borehole heat exchanger implies forced convection, resulting in an increased efficiency of the heat transfer between the ground and the borehole heat exchanger. Studying this process may suggest new ways to improve the efficiency and to reduce the cost of ground source heat pump systems. In this thesis, the contribution of groundwater flow in the heat transfer process between borehole heat exchangers and surrounding ground has been investigated, in order to increase the theoretical knowledge as well as to improve the existing design tools. Two-dimensional models have been considered, taking into account the actual cylindrical geometry of the borehole. The groundwater flow has been modeled as steady, horizontal and with variable flow rates, in order to encompass most of the real ground source heat pump applications. Gravitational effects, i.e. the effects of a possible natural convection, have been neglected. The results suggest that in the considered range of Darcy number, the calculation of the heat transfer efficiency is not affected if Darcynian model is used to describe the velocity field, although the viscous effects, and consequently the formation of the hydraulic boundary layer, are neglected. Calculations made using numerical simulations are compared with an analytical solution which takes into account forced convection due to groundwater flow and based on the linear heat source model. The regions of space and time where this analytical solution is affected by the effects of the line source assumption, in both cases of single- and multiple-borehole(s) systems, have been defined. The potential of the thermal response test analysis as a tool to predict the spacing between boreholes when groundwater flow occurs has been investigated, defining and studying the Influence Length as function of groundwater flow rate. The results suggest that even relatively low flow rates allow to reduce significantly the spacing between boreholes in the perpendicular direction with respect to groundwater flow. The distance from the borehole where the temperature disturbance becomes not-significant (Influence Length) is roughly predictable by thermal response test analysis. The study of the Influence Length may be a useful tool in the design of dissipative multiple-boreholes systems, as well as in areas with a high density of single-borehole plants, to reduce the spacing avoiding thermal interferences. Moreover, an expeditious, graphical method to estimate the hydraulic conductivity of the ground by thermal response test analysis has been proposed. An example of application of the methodology is presented, taking into account experimental data as well as plausible hydrological and petrological assumptions when the data are unavailable. The obtained result is in agreement with the hydraulic conductivity range reported in literature for the type of substrate considered in the example. In order to verify this method, further inv1estigations and developments are required. In fact, the graphs used in the procedure presented in this work are referred to specific borehole conditions (borehole filled by groundwater) and are based on two-dimensional models (i.e. end-effects and natural convection are neglected). Besides, the assumptions required to compensate the unavailable data imply that the method cannot be considered verified. Finally, further studies are suggested in order to improve and develop the proposed methods.
Negli ultimi anni, l’utilizzo del calore geotermico tramite pompe di calore accoppiate al terreno sta aumentando significativamente in tutta Europa e in generale nel mondo. In Italia, alla fine del 2010, le sonde geotermiche coprivano più del 30% dell’energia totale utilizzata per riscaldamento e raffrescamento degli edifici, mostrando un aumento del 50% rispetto al 2005. Le previsioni per il 2015 suggeriscono un ulteriore aumento degli utilizzi diretti del calore geotermico maggiore del 50% rispetto al 2010 e un analogo incremento del consumo di energia geotermica in generale. Con l’aumento della diffusione di questa tecnologia, e quindi un maggior sfruttamento di tale risorsa, aumenta anche la necessità di progettare impianti con la massima efficienza possibile e con bassi costi di installazione ed esercizio. La comprensione dei processi coinvolti nel trasferimento di calore tra sonda geotermica e terreno circostante è fondamentale per prevedere il comportamento degli impianti. Anche la conoscenza delle caratteristiche idrogeologiche del sito specifico nel quale l’impianto deve essere installato è essenziale al fine di evitare un’errata progettazione che può causare sovra- o sotto-dimensionamento della sonda. Nel corso degli anni, diverse soluzioni analitiche sono state proposte per calcolare la distribuzione di temperatura attorno alla sonda geotermica durante il suo utilizzo. Il modello analitico della sorgente di calore lineare e infinita considera lo scambio di calore che avviene per sola conduzione attorno ad una sorgente di raggio infinitesimo e di lunghezza infinita. Altri modelli successivi a questo e anch’essi basati sulla sorgente di calore lineare ed infinita, tengono conto anche del contributo convettivo dovuto al flusso dell’acqua di falda. La presenza di un flusso di acqua attorno ad una sonda geotermica, infatti, comporta convezione forzata e, di conseguenza, un aumento dello scambio di calore tra sonda e terreno. Per questo motivo, lo studio degli effetti di tale processo è un fattore chiave per riuscire a migliorare l’efficienza degli scambiatori di calore accoppiati al terreno. Questa tesi presenta lo studio del contributo del flusso delle acque di falda sul processodi scambio termico tra sonde geotermiche e terreno circostante, al fine di incrementare la conoscenza teorica e migliorare gli strumenti di progettazione già esistenti. Per raggiungere questo scopo ci si è serviti di modelli numerici bi-dimensionali che tengono conto della reale geometria cilindrica della sonda. Il fusso delle acque di falda è stato assunto come stazionale e orizzontale. Al fine di includere la maggior parte delle applicazioni geotermiche reali, un vasto range di portate è stato preso in considerazione. Gli effetti gravitativi, e quindi i possibili effetti di convezione naturale, sono stati invece trascurati. Sono stati confrontati i risultati del calcolo del trasferimento di calore ottenuti utilizzando rispettivamente l’equazione di Darcy e l’equazione di Darcy-Brinkman per descrivere il campo di velocità dell’acqua di falda attorno alla sonda. Le conclusioni raggiunte suggeriscono che utilizzando il modello di Darcy, il risultato risulta comunque sufficientemente accurato per i numeri di Darcy considerati, nonostante gli effetti viscosi, e quindi la formazione dello strato-limite fluidodinamico, vengano trascurati. I risultati delle simulazioni numeriche sono stati comparati con un modello analitico che prevede convezione forzata, dovuta al flusso di falda, attorno ad una sorgente di calore lineare ed infinita. Sono quindi state definite le regioni dello spazio e del tempo dove tale soluzione analitica è soggetta agli effetti della linearit`a della sorgente, sia nel caso di sonda singola, sia nel caso di campo-sonde. Sono inoltre state studiate le potenzialità dell’analisi del test di risposta termica come strumento per prevedere la spaziatura tra le sonde in funzione della portata del flusso dell’acqua di falda. I risultati suggeriscono che portate relativamente modeste, permettono una riduzione significativa della spazitura tra le sonde in direzione perpendicolare rispetto a quella di scorrimento dell’acqua di falda. Sfruttando l’analisi del test di risposta termica, è possibile stimare approssimativamente la distanza dalla sonda alla quale il disturbo di temperatura diventa trascurabile (distanza di influenza). Lo studio di questa distanza di influenza pu`o essere un utile strumento per la progettazione di sistemi dissipativi composti da sonde multiple, così come nelle aree con un’alta densità di impianti a sonda singola, al fine di ridurre la spaziatura tra le sonde, evitando allo stesso tempo l’insorgere di interferenze termiche tra sonde adiacenti. Inoltre è stato proposto un metodo grafico e speditivo per la stima della conducibilità idraulica del substrato tramite l’analisi del test di risposta termica. È stato presentato un esempio dell’applicazione di questa metodologia utilizzando sia dati sperimentali sia assunzioni plausibili di carattere idrologico e petrologico, quando non è stato possibile avvalersi di dati sperimentali. I risultati ottenuti sono in accordo con i valori di conducibilità idraulica proposti in letteratura per il tipo di substrato dell’esempio. Per poter verificare l’affidabilità di questo metodo, ulteriori studi e sviluppi sono sono necessari. Infatti, i grafici utilizzati nella procedura presentata in questa tesi, si riferiscono a specifiche condizioni della sonda (acqua di falda come materiale di riempimento) e sono inoltre basati su modelli bi-dimensionali (trascurando quindi gli effetti di fine-pozzo e il contributo della convezione naturale). Infine vengono forniti suggerimenti riguardo ulteriori studi che consentirebbero di migliorare e sviluppare ulteriormente le metodologie proposte.
XXVI Ciclo
1985
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Lapp, Anthony. "Seasonal Variability of Groundwater Contribution to Watershed Discharge in Discontinuous Permafrost in the North Klondike River Valley, Yukon." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32298.

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The objectives of this thesis were: (1) to quantify seasonal groundwater contribution to total stream discharge and (2) further our understanding of sub-arctic carbon sources and pathways within a sub-arctic discontinuous permafrost river catchment. Twenty-two samples were taken from the North Klondike River, 14 samples from 5 of its tributaries, and 46 rain and snowmelt samples from the Dawson City Airport, Yukon, Canada,. During the winter months, groundwater is responsible for greater than 95% of total river discharge. Spring freshet and summer flow bring snowmelt and precipitation, contributing anywhere from 30% to greater than 60% of total river discharge. Groundwater is characterised by high concentrations of geogenic solutes from weathering during recharge, dissolved inorganic carbon, and carbon-14 activities of 0.61 pMC. Tritium activities indicate a fast moving system, with groundwater ages measuring less than 10 years. The most significant discharge of organic carbon from the system is during spring freshet (434,192 kg carbon). Primary productivity within the system is estimated to be 10.2 grams of carbon per metre squared, with approximately 96% of carbon being sequestered or emitted as carbon dioxide.
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Bushman, Michelle. "Contribution of Recharge Along Regional Flow Paths to Discharge at Ash Meadows, Nevada." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2386.pdf.

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Barquin, Valle Luis Pablo. "Modeling shallow groundwater table contribution to soil water retention in the unsaturated zone of a calcareous soil of south Florida." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0025060.

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Smidt, Geerd Ahlrich [Verfasser]. "Mobility of fertiliser-derived uranium in arable soils and its contribution to uranium concentrations in groundwater and tap water / Geerd Ahlrich Smidt." Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2013. http://d-nb.info/1035267578/34.

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Garnier, Frédéric. "Contribution à l’évaluation biogéochimique des impacts liés à l’exploitation géothermique des aquifères superficiels : expérimentations et simulations à l’échelle d’un pilote et d’installations réelles." Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2079/document.

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Pour la climatisation de bâtiments ou d’installations industrielles, les nappes d’eaux superficielles représentent une source de frigories très convoitée. Leurs exploitations intensives depuis plusieurs dizaines d’années conjuguées au redéploiement de la filière géothermique ces dernières années, soulèvent des préoccupations quant à la préservation des ressources en eau. Dans ce contexte, la présente étude vise à évaluer l’impact de variations locales de température sur la qualité physico-chimique et microbiologique des eaux souterraines sur la base (i) de suivis in-situ au niveau de 3 installations réelles exploitant les nappes d’eaux superficielles et, (ii) d’expérimentations sur un pilote (BIOTHERMEX) permettant de reproduire, en conditions parfaitement maitrisées, l’effet de la propagation d’un panache thermique dans un modèle réduit d’aquifère. Dans la gamme de température relevée sur site, les principaux résultats obtenus montrent que les impacts thermiques sont circonscrits au voisinage immédiat de l’installation, pouvant altérer jusqu’à plus d’une dizaine de degrés la sténothermie des nappes. Le suivi des paramètres physico-chimiques n’ont pas fait apparaitre de perturbations significatives sur la période de surveillance, constat étayé par des modélisations hydrogéochimiques. En revanche, une influence significative a été relevée au niveau des principaux descripteurs microbiologiques (activité, diversité de la microflore totale). Enfin, les expériences menées à l’échelle du laboratoire ont permis d’appréhender finement le comportement réactionnel du système et de définir une température de réinjection critique, au-delà de laquelle des désordres potentiels sont attendus
The use of shallow groundwater as heat source for heat pump is very coveted for air-conditioning of building or industrial facilities. Their intensive use during many years combined with the redeployment of the geothermal industry these last years, raise concerns about the safeguarding of the water resources. In such a context, the present study aims to evaluate the impact of local variations of temperature on the physicochemical and microbiological quality of groundwater systems on the basis of (I) field investigation and, (II) experiments on a pilot (named BIOTHERMEX) making it possible to reproduce, in perfectly supervised conditions, the effect of the propagation of a thermal plume in a reduced aquifer model. Within the temperature recorded on site, principal outcomes showed that thermal impacts are confined in the immediate vicinity of the installation, and were able to deteriorate, up to about ten degrees, the stenothermy of the groundwater systems. The evolution of the physicochemical parameters did not reveal any significant disturbances over the monitoring period, this being also predicted by hydrogeochemical modeling. On the other hand, a significant influence was raised about some microbiological indicators-descriptors (namely activity, diversity of the total microflora). Lastly, the experiments undertaken on the laboratory scale made it possible to finely apprehend the reactional behavior of the system and to define a critical temperature of re-injection beyond which, potential disorders are expected
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Satchithanantham, Sanjayan. "Water management effects on potato production and the environment." American Society of Agricultural and Biological Engineers (ASABE), 2012. http://hdl.handle.net/1993/22279.

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Potatoes (Solanum tuberosum) were grown in a fine sandy loam soil in southern Manitoba in a three-year field study comparing four water management treatments: No Drainage with No Irrigation (NDNI), No Drainage with Overhead Irrigation (NDIR), Free Drainage with Overhead Irrigation (FDIR), and Controlled Drainage with Subirrigation (CDSI). The objectives of the study were (i) to evaluate the effect of the four treatments on yield and quality of potatoes, (ii) to evaluate the effect of water management on the environment, (iii) to estimate the shallow groundwater contribution to potato water requirement, and (iv) to simulate the shallow groundwater hydrology using the DRAINMOD and HYDRUS 1-D model. Subsurface drains were installed at 0.9 m depth and at spacings of 15 m (FDIR) and 8 m (CDSI). Subirrigation was done by pumping water back into the tiles through the drainage control structures. Overhead irrigation was carried out using a travelling gun. Water table depth, soil water content, drainage outflow, nutrient concentration in drainage water, irrigation rate, weather variables, potato yield and quality parameters, and biomass were measured. Compared to the NDNI treatment, the potato yield increase in the other treatments ranged between 15-32% in 2011 and 2-14% in 2012. In 2011, potato yield from FDIR was higher than CDSI (p = 0.011) and NDNI (p = 0.001), and yield from NDIR was higher than NDNI (p = 0.034). In 2012, potato yield was higher in FDIR in comparison to NDNI (p = 0.021). In 2012, the NDIR gave higher dark ends (p = 0.008) compared to other treatments. Under dry conditions, up to 92% of the potato crop water demand could be met by shallow groundwater contribution. Compared to free drainage, controlled drainage was able to lower the nitrate export by 98% (p = 0.033) in 2010 and by 67% (p = 0.076) in 2011, and the phosphate export decreased by 94% (p = 0.0117) in 2010. A major part of the drainage flow and nutrient export took place between April and June in southern Manitoba. DRAINMOD was able to accurately predict the shallow groundwater hydrology for this particular research site.
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Книги з теми "Groundwater contribution"

1

Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

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Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 2000.

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Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 2000.

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4

Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

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5

Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 2000.

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6

Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

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7

Gingerich, Stephen B. Ground-water occurrence and contribution to streamflow, northeast Maui, Hawaii. Honolulu, Hawaii: U.S. Dept. of the Interior, U.S. Geological Survey, 2000.

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8

Warner, James W. Ground-water contribution to the salinity of the Upper Colorado River Basin. Lakewood, Colo: U.S. Dept. of the Interior, Geological Survey, 1985.

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Warner, James W. Ground-water contribution to the salinity of the Upper Colorado River Basin. Lakewood, Colo: U.S. Dept. of the Interior, Geological Survey, 1985.

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10

Warner, James W. Ground-water contribution to the salinity of the Upper Colorado River Basin. Lakewood, Colo: U.S. Dept. of the Interior, Geological Survey, 1985.

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Частини книг з теми "Groundwater contribution"

1

Seward, P., Y. Xu, and A. Turton. "Using backcasting to explore ways to improve the national water department's contribution to good groundwater governance in South Africa." In Groundwater, 42–58. London: Routledge, 2023. http://dx.doi.org/10.4324/9781003345862-5.

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2

Mujere, N. "Contribution of groundwater towards urban household water security." In Groundwater for Sustainable Livelihoods and Equitable Growth, 95–99. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003024101-5.

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3

Sherif, Mohsen, Abdel Azim Ebraheem, Ampar Shetty, Ahmed Sefelnasr, Khaled Alghafli, and Mohamed Al Asam. "Evaluation of the Effect of the Wadi Bih Dam on Groundwater Recharge, UAE." In Natural Disaster Science and Mitigation Engineering: DPRI reports, 509–27. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-2904-4_21.

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AbstractIn Ras Al Khaimah, UAE, groundwater from the alluvial aquifer in Wadi Bih was the only source of freshwater for various uses prior to the construction of a seawater desalination plant in 1998. This study was conducted to evaluate the effect of the Wadi Bih dam on groundwater resources and to increase knowledge of the hydrodynamics of the aquifer. A local-scale numerical groundwater flow model was developed and used to investigate the impacts of different groundwater management options on groundwater resources. The calibrated and validated model was defined as the base case, and subsequently, simulations were performed to analyze different management scenarios. The simulations indicated that maximum recharge occurred during years of high rainfall (1995–1998). Minimum recharge occurred in 2000, 2002, and 2004. The major contribution to the water balance was from subsurface inflows from the upper wadi zone and the two tributaries. Overall, the annual water balance was negative in most years, with an average net decline of 0.6 MCM per year, indicating a slow but continuous depletion of groundwater resources. At the end of the simulation, the total groundwater recharge due to rainfall and water storage in the ponding area was 9.81 MCM.
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Chandrakanth, M. G. "Supply-Side Economic Contribution of Watershed Programme to Groundwater Recharge." In Water Resource Economics, 139–48. New Delhi: Springer India, 2015. http://dx.doi.org/10.1007/978-81-322-2479-2_10.

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Yamada, Chusei. "Comment: The ILC’s Contribution to the Peaceful Sharing of Transboundary Groundwater." In Peace through International Law, 173–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-03380-3_15.

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Bourhane, Anli, Jean-Christophe Comte, Jean-Lambert Join, and Kassim Ibrahim. "Groundwater Prospection in Grande Comore Island—Joint Contribution of Geophysical Methods, Hydrogeological Time-Series Analysis and Groundwater Modelling." In Active Volcanoes of the Southwest Indian Ocean, 385–401. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-642-31395-0_24.

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Almeida, Alexandre M., Paula M. Carreira, José Manuel Marques, Jorge Espinha Marques, Marina Paiva, Alexandra Carvalho, and Catarina Mansilha. "Groundwater Contribution to Alpine Ponds Recharge in Serra Da Estrela Natural Park, Portugal." In Advances in Geoethics and Groundwater Management : Theory and Practice for a Sustainable Development, 157–61. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-59320-9_34.

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Matz-Lück, Nele. "The Benefits of Positivism: The ILC’s Contribution to the Peaceful Sharing of Transboundary Groundwater." In Peace through International Law, 125–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-03380-3_12.

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Abiy, Anteneh Z., Solomon S. Demissie, Charlotte MacAlister, Shimelis B. Dessu, and Assefa M. Melesse. "Groundwater Recharge and Contribution to the Tana Sub-basin, Upper Blue Nile Basin, Ethiopia." In Springer Geography, 463–81. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-18787-7_22.

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Asfaw, Daniel, Getachew Workineh Gella, and Mulualem Asfaw. "Modeling Landscape Dynamics, Erosion Risk, and Annual Sediment Yield in Guna-tana Watershed: A Contribution for Microwatershed Level Conservation Priority Area Identification." In Groundwater Resources Development and Planning in the Semi-Arid Region, 73–91. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68124-1_4.

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Тези доповідей конференцій з теми "Groundwater contribution"

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Ramdhan, A., A. Arifin, and R. Suwarman. "Assessing Groundwater-Citarum River Interaction and Groundwater Contribution to Flooding." In NSG2021 27th European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2021. http://dx.doi.org/10.3997/2214-4609.202120067.

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M. Gabr, A. "Non Seismic - Contribution to Groundwater Investigation, Case Studies, UAE and Egypt." In EAGE Workshop on Non-Seismic Methods. European Association of Geoscientists & Engineers, 2008. http://dx.doi.org/10.3997/2214-4609.201402599.

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Russo, Aeon, Jordan Jenckes, David Boutt, and LeeAnn Munk. "CONTRIBUTION OF FRESH SUBMARINE GROUNDWATER DISCHARGE TO THE GULF OF ALASKA." In Northeastern Section-56th Annual Meeting-2021. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021ne-361932.

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4

Igel, J., T. Gunther, H. Sulzbacher, H. Wiederhold, and M. Kuntzer. "GPR investigations of an island aquifer as a contribution to groundwater modelling." In 2012 14th International Conference on Ground Penetrating Radar (GPR). IEEE, 2012. http://dx.doi.org/10.1109/icgpr.2012.6254960.

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Welch, Eric M. "GROUNDWATER CONTRIBUTION TO GLYPHOSATE CONCENTRATIONS IN THE FAGA`ALU STREAM, AMERICAN SAMOA." In 113th Annual GSA Cordilleran Section Meeting - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017cd-292458.

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Yamamoto, Yuhei, Daisuke Aosai, and Takashi Mizuno. "Evaluation of Behavior of Rare Earth Elements Based on Determination of Chemical State in Groundwater in Granite." In ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2010. http://dx.doi.org/10.1115/icem2010-40072.

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The chemical state of rare earth elements (REEs) in groundwater was determined by a combination of ultrafiltration techniques maintaining in–situ pressures and anaerobic conditions, speciation considering contribution of natural organic matter, and fingerprinting using REE patterns of the stability constants for probable complexes of REEs in groundwater. Groundwater samples were collected from a horizontal borehole at a depth of 200 mbGL (meter below ground level) in the Mizunami Underground Research Laboratory (MIU), Gifu, Japan. Spectroscopic analysis for colloidal matter on a membrane filter was also conducted to estimate chemical properties of colloidal ligands. Results of this study suggest that REEs–humic complexes are the dominant chemical states of REEs in this groundwater. The presence of humic substances in groundwater was also confirmed by spectroscopic analysis. Thus, it is expected that chemical behavior of REEs mainly is dependent on humic substances. The information of chemical state of REEs is useful for prediction of behavior of trivalent actinides in groundwater.
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Barnes, Austin, Shellie Habel, Kian Bagheri, Yousef Sangsefidi, Hassan Tavakol-Davani, and Mark Merrifield. "INVESTIGATING CONTRIBUTION OF SEA LEVEL INDUCED GROUNDWATER SHOALING TO URBAN FLOODING IN IMPERIAL BEACH, CALIFORNIA." In GSA Connects 2022 meeting in Denver, Colorado. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022am-383928.

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Maillol, J. M., J. Ortega‐Ramírez, W. L. Bandy, and A. Valiente‐Banuet. "Contribution of Electrical Resistivity Methods to Paleoenvironmental Reconstruction and Groundwater Exploration in the Chihuahua Desert, Mexico." In Symposium on the Application of Geophysics to Engineering and Environmental Problems 2000. Environment and Engineering Geophysical Society, 2000. http://dx.doi.org/10.4133/1.2922710.

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Roy, J., M. W. Lubczynski, R. J. Sporry, and W. A. Hugens. "Contribution from EM surveys to a regional groundwater resource quantification project in a hard rock area." In 3rd EEGS Meeting. European Association of Geoscientists & Engineers, 1997. http://dx.doi.org/10.3997/2214-4609.201407314.

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Maillol, J. M., J. Ortega-Ramirez, W. L. Bandy, and A. Valiente-Banuet. "Contribution Of Electrical Resistivity Methods To Paleoenvironmental Reconstruction And Groundwater Exploration In The Chihuahua Desert, Mexico." In 13th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems. European Association of Geoscientists & Engineers, 2000. http://dx.doi.org/10.3997/2214-4609-pdb.200.2000_121.

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Звіти організацій з теми "Groundwater contribution"

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Bunce, Lauren, Tim Lowenstein, and Elliot Jagniecki. Spring, River, and Lake Water Analyses from the Great Salt Lake Basin, Northern Utah. Utah Geological Survey, September 2022. http://dx.doi.org/10.34191/ofr-745.

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The accompanying database is a compilation of major and minor ion chemistry data from spring, river, and lake water samples collected in and around Great Salt Lake (GSL), northern Utah. The purpose of this database is to provide an updated analysis of previously sampled spring, river, and lake water chemistries by Kirby and others (2019) (https://doi.org/10.34191/ofr-699) and to add additional locations and water chemistry of unsampled springs in the area around GSL to better understand solute load and groundwater contribution.
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Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7592117.bard.

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Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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3

Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709883.bard.

Повний текст джерела
Анотація:
Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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4

Bécu, V., A.-A. Sappin, and S. Larmagnat. User-friendly toolkits for geoscientists: how to bring geology experts to the public. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/331220.

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Анотація:
A growing number of countries are committed toreduce their carbon emissions and are transitioning towards renewable and clean energy sources, leading to an in crease in demand formetals and minerals. This is especially the case for a short list of what are called "critical minerals" which are considered essential to economic development, including the transition to a low-carbon economy and national security. There liability of their supply chain raises concerns considering geological scarcity, difficulty to extract and/or political factors influencing their availability. At the same time, public awareness and perception of geoscience are eroding and there is more and more reluctance towards mining projects, even from traditionally favourable communities. To face this challenge, promote public interest and outline the contribution of geological science to society, geoscientists of the Geological Survey of Canada (GSC-Québec) have designed and put together a portable display that includes a suite of mineral and metal samples considered critical for the sustainable success of Canada's transition towards a clean and digital economy. The display is a user-friendly toolkit that can be used by any GSC geoscientists during outreach activities, in classrooms as well as during public open houses. It comes with straightforward pedagogic material and content, along with presentation scenarios. To broaden and adapt the workshops to specific expectations, additional toolkits were developed and all are contained within easy to carry travel cases. These cover a variety of topics and can be presented as stand-alone displays or be used complementary to one another. For example, the "Mines and minerals" collection may serve as a supplement to the "Critical minerals" display to present every day objects in which minerals are used as well as ores amples from active mines to illustrate the intertwining between mining activities and our everyday lives. Another display covers the ever-popular fossils thematic with the "Sedimentary rocks and fossils" collection and gives an opportunity to address key geoscience themes such as life evolution and biological crisis along with groundwater reservoirs and resources. The "Magmatic rocks" display touches on the formation of rocks from magmas, the different types and active processes of volcanoes, and discusses the risks and benefits related to volcanic activity. Hopefully, these four ready-to-use portable displays will encourage more GSC geoscientists to engage in public oriented activities to make geosciences more accessible, change perceptions and offer an overall tangible scientific experience for people.
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5

Lacerda Silva, P., G. R. Chalmers, A. M. M. Bustin, and R. M. Bustin. Gas geochemistry and the origins of H2S in the Montney Formation. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329794.

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The geology of the Montney Formation and the geochemistry of its produced fluids, including nonhydrocarbon gases such as hydrogen sulfide were investigated for both Alberta and BC play areas. Key parameters for understanding a complex petroleum system like the Montney play include changes in thickness, depth of burial, mass balance calculations, timing and magnitudes of paleotemperature exposure, as well as kerogen concentration and types to determine the distribution of hydrocarbon composition, H2S concentrations and CO2 concentrations. Results show that there is first-, second- and third- order variations in the maturation patterns that impact the hydrocarbon composition. Isomer ratio calculations for butane and propane, in combination with excess methane estimation from produced fluids, are powerful tools to highlight effects of migration in the hydrocarbon distribution. The present-day distribution of hydrocarbons is a result of fluid mixing between hydrocarbons generated in-situ with shorter-chained hydrocarbons (i.e., methane) migrated from deeper, more mature areas proximal to the deformation front, along structural elements like the Fort St. John Graben, as well as through areas of lithology with higher permeability. The BC Montney play appears to have hydrocarbon composition that reflects a larger contribution from in-situ generation, while the Montney play in Alberta has a higher proportion of its hydrocarbon volumes from migrated hydrocarbons. Hydrogen sulphide is observed to be laterally discontinuous and found in discrete zones or pockets. The locations of higher concentrations of hydrogen sulphide do not align with the sulphate-rich facies of the Charlie Lake Formation but can be seen to underlie areas of higher sulphate ion concentrations in the formation water. There is some alignment between CO2 and H2S, particularly south of Dawson Creek; however, the cross-plot of CO2 and H2S illustrates some deviation away from any correlation and there must be other processes at play (i.e., decomposition of kerogen or carbonate dissolution). The sources of sulphur in the produced H2S were investigated through isotopic analyses coupled with scanning electron microscopy, energy dispersive spectroscopy, and mineralogy by X-ray diffraction. The Montney Formation in BC can contain small discrete amounts of sulphur in the form of anhydrite as shown by XRD and SEM-EDX results. Sulphur isotopic analyses indicate that the most likely source of sulphur is from Triassic rocks, in particular, the Charlie Lake Formation, due to its close proximity, its high concentration of anhydrite (18-42%), and the evidence that dissolved sulphate ions migrated within the groundwater in fractures and transported anhydrite into the Halfway Formation and into the Montney Formation. The isotopic signature shows the sulphur isotopic ratio of the anhydrite in the Montney Formation is in the same range as the sulphur within the H2S gas and is a lighter ratio than what is found in Devonian anhydrite and H2S gas. This integrated study contributes to a better understanding of the hydrocarbon system for enhancing the efficiency of and optimizing the planning of drilling and production operations. Operators in BC should include mapping of the Charlie Lake evaporites and structural elements, three-dimensional seismic and sulphate ion concentrations in the connate water, when planning wells, in order to reduce the risk of encountering unexpected souring.
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6

Looney, B., C. Eddy-Dilek, M. Amidon, J. Rossabi, and L. Stewart. INDEPENDENT TECHNICAL REVIEW OF THE FOCUSED FEASIBILITY STUDY AND PROPOSED PLAN FOR DESIGNATED SOLID WASTE MANAGEMENT UNITS CONTRIBUTING TO THE SOUTHWEST GROUNDWATER PLUME AT THE PADUCAH GASEOUS DIFFUSION PLANT. Office of Scientific and Technical Information (OSTI), May 2011. http://dx.doi.org/10.2172/1017433.

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