Bibliografie tematiche / Near-surface aquifer

Indice

  1. Articoli di riviste
  2. Tesi
  3. Libri
  4. Capitoli di libri
  5. Atti di convegni
  6. Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Near-surface aquifer"

Autore: Grafiati
Pubblicato: 9 novembre 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Near-surface aquifer".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Near-surface aquifer"

1

Wu, Peipeng, Jean-Christophe Comte, Lijuan Zhang, Shuhong Wang e Bin Chang. "Effect of Surface Water Level Fluctuations on the Performance of Near-Bank Managed Aquifer Recharge from Injection Wells". Water 13, n. 21 (27 ottobre 2021): 3013. http://dx.doi.org/10.3390/w13213013.

Testo completo
Abstract (sommario):
Managed aquifer recharge operations are often conducted in near-bank areas to regulate water resources or reduce seawater intrusion. Yet little is known about the influence of surface water level fluctuations at different temporal scales on MAR performance. A generalized conceptual model was developed based on an investigation site in Western China as a basis to simulate the response surface water level fluctuations on the water table, artificially recharged water lens (formed by the artificially recharged water), groundwater flow paths and average travel times (which is an important control on how quickly contaminants are flushed out of aquifers), and the discharge of the artificially recharged aquifer during the surface water level fluctuation. The results showed a fluctuating groundwater table in the artificially recharged near-bank aquifer under the influence of surface water level fluctuations. The peak values of the increment of the groundwater table induced by artificial recharge decreased with the increase of the period and amplitude of surface water level fluctuation, but the trough values of the increment of water table increases with that. The penetration depth of surface water into the aquifer with a fluctuating surface water level leads to a decreasing increment of the groundwater table which follows a power law. The fluctuating surface water level leads to dynamic changes of artificially recharged water lens morphology and a thinner artificially recharged water lens. A mixing zone of recharged water and ambient water could be found in the artificially recharged near-bank area, which is expected to lead to modifications in the geochemical conditions in the artificially recharged near-bank aquifer. A longer period of surface water level fluctuation leads to a longer average travel time, but the larger penetration depth of surface water and amplitude lead to a shorter average travel time. The peak discharge of the near-bank aquifer was found to decrease with the period of surface water level fluctuation, but it increases with penetration depth and amplitude. This study is important in providing insights into the performance of near-bank managed aquifer recharge with respect to surface water level fluctuation.
Gli stili APA, Harvard, Vancouver, ISO e altri
2

Sugiyanto, Didik, Ibnu Rusydy, Marwan Marwan, Dian Mutia Hidayati e Asrillah Asrillah. "A PRELIMINARY STUDY ON AQUIFER IDENTIFICATION BASED ON GEO-ELECTRICAL DATA IN BANDA ACEH, INDONESIA". Jurnal Natural 18, n. 3 (4 ottobre 2018): 122–26. http://dx.doi.org/10.24815/jn.v18i3.11204.

Testo completo
Abstract (sommario):
The aquifers exploration has been conducted at the western part of Banda Aceh, Indonesia. This research aims to explore the aquifer layer beneath the surface and to obtain the cross-section model of the aquifer. The Vertical Electrical Sounding (VES) method was applied to investigate the aquifer layer. The VES method worked as the current penetrated into the ground using of two electrodes and the potential response due to its current being measured by another two electrodes. Ten grid points of VES has performed in western part of Krueng Aceh of Banda Aceh using the ARES (Automatic Resistivity Meter). The Res1Dinv and curve matching computer software used in VES data processing and analysis. The result shows the resistivity value of aquifer in Banda Aceh city at the range of 1 – 12 Ωm for freshwater, and 0.1 – 0.6 for brackish water layer. The first aquifer (water table) found at a depth of 0.5 to 2 meters beneath the surface. The 2-meters water table mostly located near the coastal zone or downstream zone of Krueng Aceh basin and shallow depth of 0.5 meters on the upstream. More than one aquifer layers were found beneath the surface, they were separated by aquitard layer consisting of silt to clay layers.
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Wumu, Rizky Hizrah, Ahmad Zainuri e Noviar Akase. "Karakteristik Akuifer Menggunakan Metode Geolistrik Resistivity Di Kecamatan Kota Tengah Kota Gorontalo". Jambura Geoscience Review 4, n. 1 (24 gennaio 2022): 60–68. http://dx.doi.org/10.34312/jgeosrev.v4i1.12752.

Testo completo
Abstract (sommario):
Kota Tengah Subdistrict has the highest population density in Gorontalo City, with a population density of 6,755 people/km2. This high population density requires a large amount of water to meet the needs of the population, where one form of fulfillment is taken from groundwater. For this reason, it is necessary and important to know the characteristics of aquifers. This study aims to determine the characteristics of groundwater aquifers in the Kota Tengah Subdistrict. The method used is the resistivity geoelectric method to obtain aquifer characteristics in the form of material type (lithology), depth, and thickness of the aquifer. Based on the geoelectrical analysis in TS 01 there are 4 layers, namely topsoil, clay sand, sand, and clay; TS 02 contains topsoil, sand, and clay layers; TS 03 contains topsoil, sand, and clay. The study found that the lithology of the near-surface layer in the Kota Tengah subdistrict can be classified into aquifers and aquicludes. The aquifer layer is formed by sand-sized sedimentary deposits that have high permeability while the aquiclude is clay-sized which is impermeable. The aquifer layer was found starting from a depth of 0.57 m. The average thickness of the aquifer layer was 13.8 m which is interpreted as an unconfined aquifer. This study also found other deeper aquifer layers as confined aquifers that can not be further interpreted due to the limitations of the method used.
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Kocar, Benjamin D., Shawn G. Benner e Scott Fendorf. "Deciphering and predicting spatial and temporal concentrations of arsenic within the Mekong Delta aquifer". Environmental Chemistry 11, n. 5 (2014): 579. http://dx.doi.org/10.1071/en13244.

Testo completo
Abstract (sommario):
Environmental context Himalayan derived arsenic contaminates groundwater across Asia, ranging from the deltas of Ganges-Brahmaputra of Bangladesh to the interior basins of the Yangtze and Yellow Rivers in China, where more than one hundred million people are drinking water with hazardous levels of the toxin. Our ability to predict the distribution and changes in arsenic concentration in aquifers of affected regions has been limited. Here we provide a dynamic model that captures arsenic migration and can be used to forecast changes in groundwater arsenic concentrations. Abstract Unravelling the complex, coupled processes responsible for the spatial distribution of arsenic within groundwaters of South and South-East Asia remains challenging, limiting the ability to predict the subsurface spatial distribution of arsenic. Previous work illustrates that Himalayan-derived, near-surface (0 to 12m) sediments contribute a substantial quantity of arsenic to groundwater, and that desorption from the soils and sediments is driven by the reduction of AsV and arsenic-bearing iron (hydr)oxides. However, the complexities of groundwater flow will ultimately dictate the distribution of arsenic within the aquifer, and these patterns will be influenced by inherent physical heterogeneity along with human alterations of the aquifer system. Accordingly, we present a unified biogeochemical and hydrologic description of arsenic release to the subsurface environment of an arsenic-afflicted aquifer in the Mekong Delta, Kandal Province, Cambodia, constructed from measured geochemical profiles and hydrologic parameters. Based on these measurements, we developed a simple yet dynamic reactive transport model to simulate one- and two-dimensional geochemical profiles of the near surface and aquifer environment to examine the effects of subsurface physical variation on the distribution of arsenic. Our results show that near-surface release (0–12m) contributes enough arsenic to the aquifer to account for observed field values and that the spatial distribution of arsenic within the aquifer is strongly affected by variations in biogeochemical and physical parameters. Furthermore, infiltrating dissolved organic carbon and ample buried particulate organic carbon ensures arsenic release from iron (hydr)oxides will occur for hundreds to thousands of years.
Gli stili APA, Harvard, Vancouver, ISO e altri
5

Mažeika, Jonas, Tõnu Martma, Rimantas Petrošius, Vaidotė Jakimavičiūtė-Maselienė e Žana Skuratovič. "Radiocarbon and Other Environmental Isotopes in the Groundwater of the Sites for a Planned New Nuclear Power Plant in Lithuania". Radiocarbon 55, n. 2 (2013): 951–62. http://dx.doi.org/10.1017/s0033822200058100.

Testo completo
Abstract (sommario):
The assessment of construction sites for the new Visaginas Nuclear Power Plant (Visaginas NPP), including groundwater characterization, took place over the last few years. For a better understanding of the groundwater system, studies on radiocarbon; tritium; stable isotopes of hydrogen, oxygen, and carbon; and helium content were carried out at the location of the new NPP, at the Western and Eastern sites, as well as in the near-surface repository (NSR) site. Two critical depth zones in the Quaternary aquifer system were characterized by different groundwater residence times and having slightly different stable isotope features and helium content. The first shallow interval of the Quaternary multi-aquifer system consists of an unconfined aquifer and semiconfined aquifer. The second depth interval of the system is related to the lower Quaternary confined aquifer. Groundwater residence time in the first flow system was mainly based on tritium data and ranges from 6 to 60 yr. These aquifers are the most important in terms of safety assessment and are considered as a potential radionuclide transfer pathway in safety assessment. Groundwater residence time in the lower Quaternary aquifers based on 14C data varies from modern to several thousand years and in some intervals up to 10,500 yr.
Gli stili APA, Harvard, Vancouver, ISO e altri
6

HENRY, J. L., P. R. BULLOCK, T. J. HOGG e L. D. LUBA. "GROUNDWATER DISCHARGE FROM GLACIAL AND BEDROCK AQUIFERS AS A SOIL SALINIZATION FACTOR IN SASKATCHEWAN". Canadian Journal of Soil Science 65, n. 4 (1 novembre 1985): 749–68. http://dx.doi.org/10.4141/cjss85-080.

Testo completo
Abstract (sommario):
The stratigraphy and hydrology of saline soils were investigated at 15 sites in Saskatchewan, Canada. At five sites (Series A) nests of piezometers were installed and at 10 sites (Series B) a single piezometer was installed in or near an aquifer. Piezometric surface data from the nests showed the potential for upward movement in all Series A sites. The electrical conductivity (EC) of water from Series A piezometers increased from the deepest to shallowest and there was a general increase in soil EC towards the soil surface. Hydraulic conductivity of strata was measured at three sites and varied from 1.6 × 10−7 to 3.2 × 10−4 cm∙sec−1. It was calculated that observed salt loads for the three sites could accumulate by upward movement from the aquifer in from 500 to 5300 yr. For Series B sites the approximate sodium percentage (ASP) of the soil (Y) was related to the ASP of the aquifer (X) by the equation:[Formula: see text]For Series A and Series B sites combined the EC (dS∙m−1) of the 1:1 suspension of the stratum immediately above the aquifer (Y) was related to the EC of the aquifer (X) by the equation:[Formula: see text]Key words: Soil salinity, aquifers, stratigraphy, salt profiles
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Darsono, Darsono, Ahmad Marzuki, Nuryani Nuryani e G. Yuliyanto. "Detection of groundwater aquifers using geoelectrical resistivity method (case study : Plupuh Sub-district, Sragen District )". Journal of Physics: Conference Series 2498, n. 1 (1 maggio 2023): 012004. http://dx.doi.org/10.1088/1742-6596/2498/1/012004.

Testo completo
Abstract (sommario):
Abstract An aquifer is a layer below the ground surface that contains groundwater. Inside the earth there are unconfined aquifers and confined aquifers, where unconfined aquifers are located near the surface while confined aquifers are located very deep beneath the earth. This study aims to find the location, depth, and thickness of aquifers that have the potential to contain large amounts of groundwater. The instrument used in this research is a resistivity meter OYO Model 2119C Mc OHM-EL, with a Schlumberger configuration with a current electrode length of AB/2 to 350 meters. Data acquisition were carried out in the Plupuh sub-district, Sragen district as many as 5 sounding points, and data processing using IP2win software. Based on the interpretation of resistivity geoelectrical data, it can be concluded that the area has the potential to have a lot of groundwater content, for unconfined aquifers at the TS1 sounding point with a depth of 7.7 meters to 19.2 meters with a thickness of 11.5 meters. and TS4 with a depth of 15.4 meters to 30 meters with a layer thickness of 14.6 meters. This aquifer layer is dominated by sand layer lithology, while the confined aquifer layer is located around TS1 and TS2. The two sounding points are located in the east and northeast of the research area. TS1 was detected at a depth of 39.9 meters to 110 meters with a layer thickness of 60.1 meters and TS2 was at a depth of 40.2 meters to 66.5 meters and 80.2 meters to 139.7 meters with a thickness of 84.8 meters. This aquifer layer is dominated by the gravel sand layer in TS1 and the sand layer in TS2.
Gli stili APA, Harvard, Vancouver, ISO e altri
8

Hinzman, Larry D., Matthew Wegner e Michael R. Lilly. "Hydrologic Investigations of Groundwater and Surface-water Interactions In Subarctic Alaska". Hydrology Research 31, n. 4-5 (1 agosto 2000): 339–56. http://dx.doi.org/10.2166/nh.2000.0020.

Testo completo
Abstract (sommario):
Dynamic interactions between rivers and adjacent aquifers can significantly affect near-bank geochemistry and processes associated with natural attenuation of contaminants by mixing water or introducing oxygen or nutrients. During 1997 and 1998 in a study near Fairbanks, Alaska U.S.A, the hydrologic conditions in the Chena River and in the adjacent groundwater were monitored. The river stage, groundwater elevations, and the water chemistry and temperature in both river and groundwater were measured. In the spring of 1997, the groundwater gradient close to the Chena River reversed causing surface water to enter the aquifer. Changes in temperature, specific conductance and alkalinity were used to determine the extent of bank recharge. For approximately one week during spring snowmelt of 1997, surface-water influx from the Chena River occurred approximately between the depths of 5.33 m and 9.1 m below ground surface. The effects of bank recharge extended at least 6.1 m but not to 30.5 m from the banks of the Chena River into the aquifer. Bank recharge caused 64 to 68 per cent of the groundwater, 6.1 m from the bank at a depth of 6.78 m to be displaced by surface water influx. Peak flows during 1998 were not high enough to cause flow reversals.
Gli stili APA, Harvard, Vancouver, ISO e altri
9

Mukherjee, S., E. A. Mohammad e R. H. Worden. "Satellite data interpretation of causes and controls on groundwater-seawater flow directions, Merseyside, UK: implications for assessing saline intrusions". Hydrology and Earth System Sciences Discussions 2, n. 3 (9 giugno 2005): 887–916. http://dx.doi.org/10.5194/hessd-2-887-2005.

Testo completo
Abstract (sommario):
Abstract. Groundwater in the Triassic Sherwood Sandstone aquifer, Liverpool, UK, has locally elevated chloride concentrations (~4000 mg/l) in parts of the coastal region although there is freshwater right up to the coast line in other areas. The aquifer is cut my numerous faults with vertical displacements of as much 300 m. SPOT satellite data have been used for the Merseyside area of Liverpool. The satellite data revealed and confirmed the location of some of the main faults since the fault zones of the aquifer have low permeability (due to grain crushing, cataclasis, and clay smearing). Where fault zones outcrop at the surface, below the well-developed regolith, there is locally elevated soil water and thus anomalous vegetation patterns in comparison to unfaulted and highly porous aquifer. The ability to identify fault zones by this satellite-based method strongly suggests that they are at least partially sealing, sub-vertical features in the aquifer. Digitally enhanced and processed satellite data were used to define the relative proportions of sand and clay in the near-coastal (inter-tidal) part of the Mersey estuary. Sand-dominated sediment has higher pixel values in comparison with clay deposits in the near infrared spectral region (NIR). Where open and weathered fault rocks crop out at the surface near the intertidal zone, water movement in these potential surface water conduits is limited where the intertidal zone is clay-dominated since clay will plug the conduit. Where these weathered and open fault-rocks crop out against sand-dominated parts of the coastline, fresh water outflux into the seawater has been imaged using the satellite data. Furthermore, the high and low chloride concentration parts of the aquifer are separated by major, sub-vertical fault zones and have allowed a very steep water table gradient to remain in the aquifer.
Gli stili APA, Harvard, Vancouver, ISO e altri
10

Peñafiel, Lilia, Francisco Javier Alcalá e Javier Senent-Aparicio. "Usefulness of Compiled Geophysical Prospecting Surveys in Groundwater Research in the Metropolitan District of Quito in Northern Ecuador". Applied Sciences 11, n. 23 (24 novembre 2021): 11144. http://dx.doi.org/10.3390/app112311144.

Testo completo
Abstract (sommario):
As in other large Andean cities, the population in the Metropolitan District of Quito (MDQ) in northern Ecuador is growing, and groundwater is becoming essential to meet the increasing urban water demand. Quito’s Public Water Supply Company (EPMAPS) is promoting groundwater research for sustainable water supply, and geophysical prospecting surveys are used to define aquifer geometry and certain transient groundwater features. This paper examines the usefulness of existing geophysical prospecting surveys in groundwater research in the MDQ. A database was built using 23 representative geophysical prospecting surveys compiled from EPMAPS’ public repository, official geotechnical research reports, and the scientific literature. Fifteen EPMAPS-promoted surveys used near-surface electrical techniques (seven used electrical resistivity tomography and eight used vertical electrical sounding) to explore Holocene and Pleistocene sedimentary and volcano-sedimentary formations in the 25–500-m prospecting depth range, some of which form shallow aquifers used for water supply. Four other surveys used near-surface seismic techniques (refraction microtremor) for geotechnical research in civil works. These surveys have been reinterpreted to define shallow aquifer geometry. Finally, four surveys compiled from the scientific literature used electromagnetic techniques (magnetotelluric sounding and other very low-frequency methods) to explore Holocene to late Pliocene formations, some of which form thick regional aquifers catalogued as the larger freshwater reservoirs in the MDQ. However, no geophysical prospecting surveys exploring the complete saturated thickness of the Pliocene aquifers could be compiled. Geophysical prospecting surveys with greater penetration depth are proposed to bridge this research gap, which prevents the accurate assessment of the renewable groundwater fraction of the regional aquifers in the MDQ that can be exploited sustainably.
Gli stili APA, Harvard, Vancouver, ISO e altri
Più fonti

Tesi sul tema "Near-surface aquifer"

1

Smith, Donna Lee. ""Redox pumping" in the near surface Missoula aquifer iin the flood plain of the Clark Fork River surface, water and groundwater interaction and arsenic related chemistry at a compost facility near a wastewater treatment plant /". CONNECT TO THIS TITLE ONLINE, 2008. http://etd.lib.umt.edu/theses/available/etd-06062008-105818/.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
2

Guha, Swagata. "Variable-Density Flow Models of Saltwater Intrusion in Coastal Landforms in Response to Climate Change Induced Sea Level Rise and a Chapter on Time-Frequency Analysis of Ground Penetrating Radar Signals". Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3490.

Testo completo
Abstract (sommario):
Populations residing on and near the world’s coasts have become increasingly dependent on coastal groundwater for their supply of freshwater. Under the conditions of predicted climate changes, the expected rise in global sea level can adversely affect the quality and quantity of freshwater resources in coastal areas as a result of saltwater intrusion. In this study, a suite of two- and three-dimensional variable-density groundwater flow models of major coastal landforms (e.g. deltas, estuaries and small islands) has been constructed to assess the effects of sea level rise (SLR), using different SLR rates of 0.5 m, 1m and 1.5 m over the next 90 years, from 2010-2100. The model results indicate that in natural coastal systems the extent of saltwater intrusion is significantly controlled by the stratigraphy of the depositional environments. Among deltaic aquifers, wave-dominated deltas are more prone to saltwater intrusion than river- and tide-dominated deltas. In case of a partially mixed, microtidal estuary, SLR can cause extensive porewater salinity increases, especially within estuarine sand deposits. Simulations of atoll and barrier islands reveal that carbonate atoll islands with high conductivity units, are severely affected by SLR, resulting in significant reduction of the volume of freshwater lens. In contrast, migrating sandy barrier islands could retain their freshwater resources with rising sea level under conditions of increased recharge, assuming the barriers can migrate in response to SLR. The freshwater lens of barrier island aquifers would reduce in size due to increased evapotranspiration caused by change in vegetation pattern. When examined for anthropogenic impacts of groundwater withdrawal through pumping, all the coastal aquifers show evidence of saltwater intrusion, with varying degrees of impact. Wave-dominated deltas are more affected by groundwater withdrawal than river- and tide-dominated deltaic aquifers. Saltwater intrusion in atoll islands is further enhanced by pumping withdrawal. It is evident from the results of the simulations that, the potential effects on coastal aquifers of groundwater withdrawals for potable water can easily exceed the adverse effects of SLR in terms of salinity increase.
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Segura, Gonzalez David Santiago. "Processus physico-chimiques et impacts environnementaux des fuites de CO2 associé au CH4 lors d’un stockage géologique sur les hydrosystèmes carbonatés proche surface. Approche expérimentale in situ et en laboratoire". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0187.

Testo completo
Abstract (sommario):
La prise de conscience de la communauté internationale et la convergence des données scientifiques autour du réchauffement climatique confirment l'urgence de déployer des technologies pour réduire les émissions de gaz à effet de serre. Cependant, ces gaz peuvent s'échapper des réservoirs géologiques profonds et migrer vers les aquifères sus-jacents et la surface. Il est donc nécessaire de mettre en place des systèmes de surveillance du stockage géologique du CO2 pour détecter ces éventuelles fuites et évaluer leur importance et leur impact sur la qualité de l'eau des aquifères. En cas de fuite dans le contexte de réservoirs utilisés pour le stockage du CO2, le CH4 résiduel du réservoir de stockage sera probablement entraîné avec le CO2. Cependant, peu d’études ont abordé les implications de la présence de CH4, et aucune son potentiel en tant que gaz précurseur permettant la surveillance des fuites d’un stockage géologique. L'étude des processus physico-chimiques et des impacts des fuites de CO2 associées au CH4 en cas de fuite sur un aquifère carbonaté proche de la surface nécessite une meilleure caractérisation des processus multi-échelles tels que la dissolution à l'échelle du réseau poreux ou le transport des panaches à l'échelle macroscopique. Les méthodes expérimentales et de modélisation utilisées individuellement donnent des réponses à des questions sur des processus particuliers, mais ces méthodes ont des limites si elles sont utilisées individuellement. Par conséquent, une approche hybride et multi-échelle est nécessaire. Le site expérimental de Saint-Émilion, avec huit forages déjà en place au niveau de l'aquifère de l'Oligocène supérieur, et les expériences passées portant sur les fuites sur les aquifères, offre une excellente opportunité pour une étude multi-échelle expérimentale et de modélisation. Dans cette thèse, l'impact des fuites a été étudié à l'échelle de la carotte en laboratoire, plus spécifiquement sur la compréhension des facteurs contrôlant les processus de dissolution tels que les faciès sédimentaires carbonatés, la vitesse de la nappe, la salinité et de la concentration de CO2. À l'échelle macroscopique, une expérience d'injection d'eau riche en CO2-CH4 a été menée sur le site de Saint-Émilion pour mieux comprendre le comportement physico-chimique du CO2 et du CH4 dans l'aquifère carbonaté. Enfin, les résultats expérimentaux ont été utilisés pour la simulation 3D du transport réactif lors d'un événement de fuite, avec le but de vérifier les résultats expérimentaux et d'étudier les processus de fuite à l'échelle macroscopique dans diverses conditions. Des relations ont été établies entre la cinétique de dissolution des carbonates, la concentration de CO2, le débit d'injection et la salinité. Des liens entre la cinétique de dissolution et l'évolution de la porosité, de la perméabilité, des paramètres électriques et le type de faciès sédimentaire ont été déterminés. L'expérience d'injection sur le site de Saint-Émilion a révélé que : i) certains paramètres physico-chimiques permettent de distinguer la fuite des gaz du signal physico-chimique naturel de l’aquifère ; ii) le déplacement du panache de CO2 est retardé par rapport au déplacement du panache de CH4 ; et iii) la corrélation entre la conductivité électrique et la concentration en CO2 permet de détecter et de suivre une fuite de CO2. De plus, l'approche par modélisation numérique du transport réactif nous a permis d'étudier comment les paramètres de la fuite peuvent modifier la propagation des panaches de CO2 et de CH4 en trois dimensions dans les milieux poreux. La modélisation a également permis d’établir l'influence des interactions de surface sur le transport du CO2 et du CH4. Ces résultats influent directement sur l'élaboration de stratégies efficaces de surveillance et d'atténuation des fuites de CO2 et de CH4 dans les sites de stockage géologique
The awareness of the international community and the convergence of scientific data around global warming confirm the urgency of deploying technologies to reduce greenhouse gas emissions. However, these gases can escape from deep geological storage and migrate to the overlying aquifers and the surface. It is therefore necessary to set up monitoring systems for geological CO2 storage to detect these possible leaks and assess their importance and impact on the water quality of the aquifers. In the event of a leak in the context of depleted reservoirs used for CO2 storage, the residual CH4 from the storage reservoir will likely be entrained with CO2. However, few studies have addressed the implications of the presence of CH4, and none have studied its potential as a precursor gas for monitoring leaks from geological storage. Studying the physicochemical processes and impacts of CO2 leakage associated with CH4 in the event of a leak on a near-surface carbonate aquifer requires better characterization of multi-scale processes such as dissolution at the scale of the porous network or the transport of plumes at the macroscopic scale. Experimental and modeling methods used individually give responses to questions on particular processes, but these methods have limitations if used individually. Therefore, a hybrid, multi-scale approach is necessary. The experimental site of Saint Émilion, with eight wells already in place at the level of the Upper Oligocene aquifer, and past experiments on leakage in this aquifer, provides an excellent opportunity for a comprehensive multi-scale experimental and modeling study. In this thesis, the impact of leakage was studied at the scale of the core in the laboratory, more specifically on the comprehension of factors that control the dissolution processes such as carbonate sedimentary facies, groundwater velocity, salinity, and CO2 concentration. At the macroscopic scale, a CO2-CH4-rich water injection experiment was conducted at the Saint-Émilion site to understand better the physicochemical behavior of CO2 and CH4 in the carbonate aquifer. Finally, the experimental results were used for the 3D simulation of the reactive transport during a leakage event, with the aim of verifying the experimental results and studying the leakage processes at the macroscopic scale under various conditions. Relationships between the dissolution kinetics for each CO2 concentration, injection rate, and salinity were established. Links between dissolution kinetics, evolution of porosity, permeability, electrical parameters, and the type of sedimentary facies were determined. The injection experiment at the Saint-Émilion site revealed that : (i) some physicochemical parameters are able to distinguish the gas leakage signal from the natural physicochemical signal of the aquifer; ii) CO2 plume displacement is retarded relative to the CH4 plume displacement; and iii) the correlation between electrical conductivity and CO2 concentration enables detection and track a CO2 leakage. Moreover, the reactive transport modeling approach has allowed us to study how the parameters of the leak can modify the propagation of CO2 and CH4 plumes in three dimensions in the porous media. Modeling also enabled to establish the influence of surface interactions on CO2 and CH4 transport. These findings directly affect the development of effective monitoring and mitigation strategies for CO2 and CH4 leaks in geological storage sites
Gli stili APA, Harvard, Vancouver, ISO e altri

Libri sul tema "Near-surface aquifer"

1

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
2

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
5

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
6

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Anderson, Mark T. Ground-water and surface-water interactions along Rapid Creek near Rapid City, South Dakota. Rapid City, S.D: U.S. Dept. of the Interior, U.S. Geological Survey, 1999.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
8

W, Kolpin Dana. Herbicides and nitrate in near-surface aquifers in the midcontinental United States, 1991. Washington: U.S. G.P.O., 1994.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
9

W, Kolpin Dana. Water-quality data for nutrients, pesticides, and volatile organic compounds in near-surface aquifers of the Midcontinental United States, 1992-1994. Iowa City, Iowa: U.S. Geological Survey, 1996.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
10

W, Kolpin Dana. Water-quality data for nutrients, pesticides, and volatile organic compounds in near-surface aquifers of the midcontinental United States, 1992-1994. Iowa City, Iowa: U.S. Dept. of the Interior, U.S. Geological Survey, 1996.

Cerca il testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Più fonti

Capitoli di libri sul tema "Near-surface aquifer"

1

Gilboy, A. E., e R. T. Hagemeyer. "Determining salinity changes within the Floridan aquifer system using three surface geophysical techniques near the Cross Florida Barge Canal, in Citrus and Levy Counties, Florida". In The Lithostratigraphy and Hydrostratigraphy of the Floridan Aquifer System in Florida: Tampa to Tallahassee, Florida July 1–7, 1989, 63–78. Washington, D. C.: American Geophysical Union, 1989. http://dx.doi.org/10.1029/ft185p0063.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
2

Al-Helal, Anwar, Yaqoub AlRefai, Abdullah AlKandari e Mohammad Abdullah. "Subsurface Stratigraphy of Kuwait". In The Geology of Kuwait, 27–50. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-16727-0_2.

Testo completo
Abstract (sommario):
AbstractThis chapter reviews the subsurface stratigraphy of Kuwait targeting geosciences educators. The lithostratigraphy and chronostratigraphy of the reviewed formations (association of rocks whose components are paragenetically related to each other, both vertically and laterally) followed the formal stratigraphic nomenclature in Kuwait. The exposed stratigraphic formations of the Miocene–Pleistocene epochs represented by the Dibdibba, Lower Fars, and Ghar clastic sediments (Kuwait Group) were reviewed in the previous chapter as part of near-surface geology. In this chapter, the description of these formations is based mainly on their subsurface presence. The description of the subsurface stratigraphic formations in Kuwait followed published academic papers and technical reports related to Kuwait’s geology or analog (GCC countries, Iraq and Iran) either from the oil and gas industry or from different research institutions in Kuwait and abroad. It is also true that studies related to groundwater aquifer systems also contribute to our understanding of the subsurface stratigraphy of Kuwait for the shallower formations. The majority of the published data were covered the onshore section of Kuwait. The subsurface stratigraphic nomenclature description is based on thickness, depositional environment, sequence stratigraphy, the nature of the sequence boundaries, biostratigraphy, and age. The sedimentary strata reflect the depositional environment in which the rocks were formed. Understanding the characteristics of the sedimentary rocks will help understand many geologic events in the past, such as sea-level fluctuation, global climatic changes, tectonic processes, geochemical cycles, and more, depending on the research question. The succession of changing lithological sequences is controlled by three main factors; sea-level change (eustatic sea level), sediment supply, and accommodation space controlled by regional and local tectonics influences. Several authors have developed theoretical methods, established conceptual models, and produced several paleofacies maps to interpret Kuwait’s stratigraphic sequence based on the data collected over time intervals from the Late Permian to Quaternary to reconstruct the depositional history of the Arabian Plate in general and of Kuwait to understand the characteristics of oil and gas reservoirs.
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Röttger, Bernd, Reinhard Kirsch, Rud Friborg, Wolfgang Scheer, Steen Thomsen e Wolfgang Voss. "26. Multifrequency Airborne EM Surveys—A Tool for Aquifer Vulnerability Mapping". In Near-Surface Geophysics, 643–52. Society of Exploration Geophysicists, 2005. http://dx.doi.org/10.1190/1.9781560801719.ch26.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Bachrach, Ran, e Tapan Mukerji. "22. Analysis of 3D High-Resolution Seismic Reflection and Crosswell Radar Tomography for Aquifer Characterization: A Case Study". In Near-Surface Geophysics, 607–20. Society of Exploration Geophysicists, 2005. http://dx.doi.org/10.1190/1.9781560801719.ch22.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
5

Parra, Jorge O., Chris L. Hackert, Michael Bennett, Michael Jervis e Hughbert A. Collier. "13. An Integrated Approach Based on NMR/Acoustic Techniques to Map Permeability in Carbonate Aquifers: From the Pore to Field Scales". In Near-Surface Geophysics, 473–90. Society of Exploration Geophysicists, 2005. http://dx.doi.org/10.1190/1.9781560801719.ch13.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
6

Iquebal Hossain, Mohammad, e Mohammad Niamul Bari. "The Unique Approaches to Water Management for Transforming Bangladesh’s Drought-prone Northwest Region into a Lush and Granary Landscape". In Arid Environment - Perspectives, Challenges and Management [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105840.

Testo completo
Abstract (sommario):
Bangladesh’s Barind Tract, lying in the country’s northwestern part, is a drought-prone water scarce area that has suffered substantial difficulties in water management for agriculture, drinking, residential, and other uses. The situation has been changed by the efforts of the Barind Multipurpose Development Authority (BMDA). So, the focus of this research is on the numerous initiatives of the BMDA to transform the arid-like Barind area into a green and granary landscape through efficient water management. To achieve this goal, various data sets about water resources development and management, as well as other necessary information were collected from the BMDA and other sources and analyzed. Irrigation was initiated using groundwater (GW) through the installation of deep tube wells (DTWs). DTWs located near the localities are also used to provide drinking water to rural people. Then, by re-excavating derelict ponds, kharis (canals), and other water bodies and constructing cross-dams (check dams) and rubber dams in the re-excavated kharies and rivers, surface water (SW) augmentation is started, mostly for supplementary irrigation. Conserved water develops the environment and enhances groundwater recharge (GWR) alongside irrigation. Constructed dug wells in the severely water-stressed areas having no sources of SW and GW supply irrigation for low-water-consuming crops. Pre-paid metering in the irrigation management system has minimized the overuse of water, while the underground pipe water distribution system has reduced water transportation and evaporation losses. The application of managed aquifer recharge (MAR) model helps enhance GWR. Finally, BMDA’s efforts have transformed the Barind Tract, as well as Bangladesh’s northwest region, into a lush and granary terrain.
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Margat, Jean. "Water Resources". In The Physical Geography of the Mediterranean. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780199268030.003.0037.

Testo completo
Abstract (sommario):
The geography of natural water resources in the Mediterranean basin cannot simply be reduced to the study of water inputs, water distribution, and the pattern of runoff-generating precipitation determined by climate and relief—although these are, of course, fundamental controls (Margat 1992; Benblidia et al. 1996). Any consideration of basin-wide water resources also needs to consider a range of territorially determined factors affecting water resources. These include: (1) the nature of surface and underground flows, which depends on river basin and hydrogeological characteristics; (2) the natural storage capacity of lakes and aquifers and their role in regulating flows, and any losses from these stores which reduce the resulting flows; (3) the existence of favourable conditions for water management and exploitation such as suitable sites for dam construction and the productivity of aquifers, as these factors dictate accessibility to water resources and the production costs; (4) the natural quality of the water, its vulnerability to pollution and its capacity for self-purification; (5) any constraints imposed for reasons of environmental conservation, which may effectively exclude a proportion of water reserves from the category of exploitable resources. It is important to appreciate that each of these factors influences the assessment of water resources in a given area and each factor has its own geography (Margat 1997; Margat and Vallée 1999a). In spite of the broad similarities in climate and landscape between the different parts of the Mediterranean basin, there are considerable variations between regions that impact upon the availability of water resources. Many of the factors affecting water resources cited above are subject to a similar degree of variation (Grenon and Batisse 1989; Chapter 8) and these are discussed in turn below. Marking the transition between the temperate climate of Europe and the aridity of North Africa and the Near East, the Mediterranean climate contains wide variation, and this is reflected in a highly uneven distribution of rainfall (Benblidia et al. 1996; Margat and Vallée 1999a; Chapter 3). For example, moving from one extreme to another, average annual rainfall ranges from more than 3,000 mm in parts of the Dinaric Alps to less than 50 mm in Libya.
Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Near-surface aquifer"

1

Doetsch, J., E. Auken, A. V. Christiansen e G. Fiandaca. "3-D Time-lapse Electrical Resistivity Monitoring of Injected CO2 in a Shallow Aquifer". In Near Surface Geoscience 2013. Netherlands: EAGE Publications BV, 2013. http://dx.doi.org/10.3997/2214-4609.20131374.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
2

Hermans, T., S. Wildemeersch, P. Jamin, P. Orban, S. Brouyère, A. Dassargues e F. Nguyen. "A Heat Injection and Pumping Experiment in a Gravel Aquifer Monitored with Crosshole Electrical Resistivity Tomography". In Near Surface Geoscience 2013. Netherlands: EAGE Publications BV, 2013. http://dx.doi.org/10.3997/2214-4609.20131372.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Balwant, P., V. Jyothi, R. Quamar, S. Shende, A. Mishra, R. Janipella, S. Chonde, C. Padmakar, A. K. Soni e P. R. Pujari. "Assessment of Sea water Ingress in coastal aquifer and Identification of Suitable Sites for Rainwater Harvesting to resists Ingress in Coastal aquifer of Jafrabad District, India". In 1st Indian Near Surface Geophysics Conference & Exhibition. European Association of Geoscientists & Engineers, 2019. http://dx.doi.org/10.3997/2214-4609.201979041.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Falgàs, E., G. Marquis, P. Sailhac, J. Ledo, P. Queralt e M. Béhaegel. "Aquifer Imaging Using CSAMT and ERT". In Near Surface 2005 - 11th European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2005. http://dx.doi.org/10.3997/2214-4609-pdb.13.p038.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
5

Vouillamoz, J. M., A. Legchenko, J. Hoareau e M. Grammare. "Improving Aquifer Characterization Using Magnetic Resonance Sounding". In Near Surface 2009 - 15th EAGE European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2009. http://dx.doi.org/10.3997/2214-4609.20147012.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
6

Suarez, G. M., S. Miong, J. Wong, R. R. Stewart, A. D. Alcudia, H. Lu e K. Al Dulaijan. "Well-logging and Near-surface Seismic Methods for Aquifer Detection". In Near Surface 2008 - 14th EAGE European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2008. http://dx.doi.org/10.3997/2214-4609.20146251.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Plata, J. L., M. Riveira e P. Ibarra. "Recovering Old Geophysical Documents for Deep Aquifer Research". In Near Surface 2008 - 14th EAGE European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2008. http://dx.doi.org/10.3997/2214-4609.20146254.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
8

Kavanda, R., e Z. Nyari. "Reconstruction of Groundwater Aquifer Models with Cluster Analysis". In Near Surface 2009 - 15th EAGE European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2009. http://dx.doi.org/10.3997/2214-4609.20147093.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
9

Canto, A., E. Bena, G. Cassiani, G. De Bacco, A. Godio e C. Strobbia. "Test Site for Aquifer Cross-Hole Investigation for Hydrogeological Purposes". In Near Surface 2005 - 11th European Meeting of Environmental and Engineering Geophysics. European Association of Geoscientists & Engineers, 2005. http://dx.doi.org/10.3997/2214-4609-pdb.13.p040.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
10

Fadilah, T., L. Gross e R. Schaa. "Estimation of Aquifer Properties Using Surface Based Electrical Resistivity Tomography". In EAGE-HAGI 1st Asia Pacific Meeting on Near Surface Geoscience and Engineering. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201800374.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Near-surface aquifer"

1

Lavoie, D., V. Tremblay e C. Rivard. Sandstone composition and diagenesis of the Paskapoo Formation and their significance for shallow groundwater aquifer in the Fox Creek area, west-central Alberta. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331923.

Testo completo
Abstract (sommario):
The shallow aquifer in the Fox Creek area is hosted by the Paleocene Paskapoo Formation. The formation consists of fluvial deposits with channel-filled high-energy sandstone cutting through fine-grained, low energy overbank sediments. Three internal members are recognized, these members define three hydrostratigraphic units (two aquifers versus one aquitard). In fall 2022, three boreholes were drilled and cored. The succession is slightly dominated by sandstone with subordinate fine-grained sediments and thin coal intervals. The calcareous to non-calcareous sandstone is either tight and well compacted or porous, friable to unconsolidated. The litharenite is composed of quartz, various types of rock fragments, chert, and feldspars. Detrital carbonates can be abundant. The post-sedimentation history of the sandstone recorded cementation and dissolution events from near surface, through shallow burial and late tectonic exhumation. The events include early clay coatings on grains, dissolution of metastable minerals, cementation from calcite, kaolinite and minor chlorite and late near surface fault-controlled freshwater circulation and dissolution. The late event resulted in friable to unconsolidated sandstone intervals.
Gli stili APA, Harvard, Vancouver, ISO e altri
2

J.L. Jerden Jr., A.J. Kropf e Y. Tsai. SURFACE COMPLEXATION OF ACTINIDES WITH IRON OXIDES: IMPLICATIONS FOR RADIONUCLIDE TRANSPORT IN NEAR-SURFACE AQUIFERS. Office of Scientific and Technical Information (OSTI), agosto 2005. http://dx.doi.org/10.2172/859262.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Kirby, Stefan M., J. Lucy Jordan, Janae Wallace, Nathan Payne e Christian Hardwick. Hydrogeology and Water Budget for Goshen Valley, Utah County, Utah. Utah Geological Survey, novembre 2022. http://dx.doi.org/10.34191/ss-171.

Testo completo
Abstract (sommario):
Goshen Valley contains extensive areas of agriculture, significant wetlands, and several small municipalities, all of which rely on both groundwater and surface water. The objective of this study is to characterize the hydrogeology and groundwater conditions in Goshen Valley and calculate a water budget for the groundwater system. Based on the geologic and hydrologic data presented in this paper, we delineate three conceptual groundwater zones. Zones are delineated based on areas of shared hydrogeologic, geochemical, and potentiometric characteristics within the larger Goshen Valley. Groundwater in Goshen Valley resides primarily in the upper basin fill aquifer unit (UBFAU) and lower carbonate aquifer unit (LCAU) hydrostratigraphic units. Most wells in Goshen Valley are completed in the UBFAU, which covers much of the valley floor. The UBFAU is the upper part of the basin fill, which is generally less than 1500 feet thick in Goshen Valley. Important spring discharge at Goshen Warm Springs issues from the LCAU. Relatively impermeable volcanic rocks (VU) occur along much of the upland parts of the southern part of Goshen Valley. Large sections of the southwest part of the Goshen Valley basin boundary have limited potential for interbasin flow. Interbasin groundwater flow is likely at several locations including the Mosida Hills and northern parts of Long Ridge and Goshen Gap in areas underlain by LCAU. Depth to groundwater in Goshen Valley ranges from at or just below the land surface to greater than 400 feet. Groundwater is within 30 feet of the land surface near and north of Goshen, in areas of irrigated pastures and wetlands that extend east toward Long Ridge and Goshen Warm Springs, and to the north towards Genola. Groundwater movement is from upland parts of the study area toward the valley floor and Utah Lake. Long-term water-level change is evident across much of Goshen Valley, with the most significant decline present in conceptual zone 2 and the southern part of conceptual zone 1. The area of maximum groundwater-level decline—over 50 feet—is centered a few miles south of Elberta in conceptual zone 2. Groundwater in Goshen Valley spans a range of chemistries that include locally high total dissolved solids and elevated nitrate and arsenic concentrations and varies from calcium-bicarbonate to sodium-chloride-type waters. Overlap in chemistry exists in surface water samples from Currant Creek, the Highline Canal, and groundwater. Stable isotopes indicate that groundwater recharges from various locations that may include local recharge, from the East Tintic Mountains, or far-traveled groundwater recharged either in Cedar Valley or east of the study area along the Wasatch Range. Dissolved gas recharge temperatures support localized recharge outside of Goshen. Most groundwater samples in Goshen Valley are old, with limited evidence of recent groundwater recharge. An annual water budget based on components of recharge and discharge yields total recharge of 32,805 acre-ft/yr and total discharge of 35,750 acre-ft/yr. Most recharge is likely from interbasin flow and lesser amounts from precipitation and infiltration of surface water. Most discharge is from well water withdrawal with minor spring discharge and groundwater evapotranspiration. Water-budget components show discharge is greater than recharge by less than 3000 acreft/yr. This deficit or change in storage is manifested as longterm water-level decline in conceptual zone 2, and to a lesser degree, in conceptual zone 1. The primary driver of discharge in conceptual zone 2 is well withdrawal. Conceptual zone 3 is broadly in balance across the various sources of recharge and discharge, and up to 1830 acre-ft/yr of water may discharge from conceptual zone 3 into Utah Lake. Minimal groundwater likely flows to Utah Lake from zones 1 or 2.
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Weissinger, Rebecca. Status and trends of springs at Hovenweep National Monument, 1999–2021. A cura di Alice Wondrak Biel. National Park Service, agosto 2023. http://dx.doi.org/10.36967/2294373.

Testo completo
Abstract (sommario):
Water is a scarce, but vital, resource at Hovenweep National Monument (NM). The National Park Service has prioritized long-term monitoring of water resources at the monument through a variety of programs and indicators since 1999. The purpose of this report is to evaluate water-quantity and water-quality data collected at long-term monitoring sites in Hovenweep NM from 1999 to 2021 for trends over time, and to summarize site-characterization data for currently monitored locations. Data are available for three active monitoring stations—Square Tower Spring, Hackberry Pool, and Goodman Point Spring—and three discontinued monitoring stations—Cajon Pool, Upper Hackberry Spring (Spring #4), and Horseshoe Spring. Water resources at Hovenweep NM have exhibited many trends over the past two decades. Pool levels at both Square Tower Spring and Hackberry Pool went up, with a step increase shown in 2016 (after no sampling in 2014–2015). In contrast, flow decreased by more than half at Goodman Point Spring and ceased at Upper Hackberry Spring (Spring #4). Flow at Horseshoe Spring also decreased, although the period of record at this site was very short. Both Upper Hackberry Spring (Spring #4) and Horseshoe Spring were removed from the monitoring rotation because flows were increasingly absent or too low to measure. Pool-level dynamics and water chemistry at Cajon Pool are characteristic of precipitation-derived water rather than groundwater; this site was removed from the monitoring rotation because it was not a good indicator of groundwater conditions. The water chemistry in both Square Tower Spring and Hackberry Pool changed significantly, but in opposite directions. Square Tower Spring had increasing total dissolved solids (TDS) and specific conductance, with all major ions showing increases over time. Hackberry Pool had decreases in TDS and most major ions through 2010, when water-chemistry lab analyses were suspended due to logistical constraints. Specific conductance continued to decrease at Hackberry Pool through 2021. The reasons for these changes are unknown. Increases in major ions at Square Tower Spring are unlikely to be related to oil and gas development in the region. Decreases in major ions at Hackberry Pool may reflect an increase in the amount of water that is entering the pool from rain and snowmelt rather than groundwater at this site. Water-quality parameters at Goodman Point Spring have remained stable. While the causes of trends in water chemistry at these sites are likely natural, the small quantities of water and harsh water-quality conditions make these sites poor habitat for aquatic life. Groundwater is naturally low in dissolved oxygen—but the dissolved-oxygen concentrations in the two pools are persistently low, sometimes falling to near zero in the summer. Water temperatures also warm in conjunction with air temperatures, with temperatures as warm as 18°C in the pools and 19°C in Goodman Point Spring. Traditionally, Puebloan cultures would have managed these small water resources to promote infiltration and retention of precipitation and to remove sediment and debris. Decreases in flow and increasing vegetation stress are likely tied to increasing air temperatures and long-term drought conditions across the region. The namesake hackberry trees at Hackberry Pool and nearby sites have shown increasing drought stress. Regionally, the underlying Dakota aquifer that feeds springs at the monument was relatively stable from 2008 to 2017, with decreasing levels from 2018 to 2021. Overall, the most concerning trends observed at springs in Hovenweep NM are likely due to climate change. Increasing air temperature threatens springflow and spring-associated vegetation through increased evapotranspiration. While pool levels have increased, recent decreases in the regional Dakota aquifer raise concerns about the stability of pools in the future. Managers could consider the potential benefits and risks of: Prioritizing protections and actions at Square Tower Spring, which has been the most resilient site at the monument in persistence of surface water and vegetation health during extreme drought. Implementing potential climate-adaptation actions that could improve groundwater infiltration upgradient of spring sites. This could include rehabilitating traditional structures to slow the flow of surface water. Implementing traditional management techniques that could increase dissolved-oxygen concentrations in the spring pools. Increasing invasive-plant removal efforts at Goodman Point Spring, which had the greatest number and cover of invasive-plant species of the three currently monitored locations. Developing interpretive stories about water-management techniques and the role of climate change in creating drought stress on iconic hackberry trees.
Gli stili APA, Harvard, Vancouver, ISO e altri
5

Russo, David, Daniel M. Tartakovsky e Shlomo P. Neuman. Development of Predictive Tools for Contaminant Transport through Variably-Saturated Heterogeneous Composite Porous Formations. United States Department of Agriculture, dicembre 2012. http://dx.doi.org/10.32747/2012.7592658.bard.

Testo completo
Abstract (sommario):
The vadose (unsaturated) zone forms a major hydrologic link between the ground surface and underlying aquifers. To understand properly its role in protecting groundwater from near surface sources of contamination, one must be able to analyze quantitatively water flow and contaminant transport in variably saturated subsurface environments that are highly heterogeneous, often consisting of multiple geologic units and/or high and/or low permeability inclusions. The specific objectives of this research were: (i) to develop efficient and accurate tools for probabilistic delineation of dominant geologic features comprising the vadose zone; (ii) to develop a complementary set of data analysis tools for discerning the fractal properties of hydraulic and transport parameters of highly heterogeneous vadose zone; (iii) to develop and test the associated computational methods for probabilistic analysis of flow and transport in highly heterogeneous subsurface environments; and (iv) to apply the computational framework to design an “optimal” observation network for monitoring and forecasting the fate and migration of contaminant plumes originating from agricultural activities. During the course of the project, we modified the third objective to include additional computational method, based on the notion that the heterogeneous formation can be considered as a mixture of populations of differing spatial structures. Regarding uncertainly analysis, going beyond approaches based on mean and variance of system states, we succeeded to develop probability density function (PDF) solutions enabling one to evaluate probabilities of rare events, required for probabilistic risk assessment. In addition, we developed reduced complexity models for the probabilistic forecasting of infiltration rates in heterogeneous soils during surface runoff and/or flooding events Regarding flow and transport in variably saturated, spatially heterogeneous formations associated with fine- and coarse-textured embedded soils (FTES- and CTES-formations, respectively).We succeeded to develop first-order and numerical frameworks for flow and transport in three-dimensional (3-D), variably saturated, bimodal, heterogeneous formations, with single and dual porosity, respectively. Regarding the sampling problem defined as, how many sampling points are needed, and where to locate them spatially in the horizontal x₂x₃ plane of the field. Based on our computational framework, we succeeded to develop and demonstrate a methdology that might improve considerably our ability to describe quntitaively the response of complicated 3-D flow systems. The results of the project are of theoretical and practical importance; they provided a rigorous framework to modeling water flow and solute transport in a realistic, highly heterogeneous, composite flow system with uncertain properties under-specified by data. Specifically, they: (i) enhanced fundamental understanding of the basic mechanisms of field-scale flow and transport in near-surface geological formations under realistic flow scenarios, (ii) provided a means to assess the ability of existing flow and transport models to handle realistic flow conditions, and (iii) provided a means to assess quantitatively the threats posed to groundwater by contamination from agricultural sources.
Gli stili APA, Harvard, Vancouver, ISO e altri
6

Potentiometric surface of the alluvial aquifer and hydrologic conditions near Caguas, Puerto Rico, March 19. US Geological Survey, 1989. http://dx.doi.org/10.3133/wri894075.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Potentiometric surface of the alluvial aquifer and hydrologic conditions near Gurabo and Juncos, Puerto Rico, March 1988. US Geological Survey, 1990. http://dx.doi.org/10.3133/wri904059.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
8

Herbicides and nitrate in near-surface aquifers in the midcontinental United States, 1991. US Geological Survey, 1994. http://dx.doi.org/10.3133/wsp2413.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Ti possono interessare anche gli elenchi estesi di opere sul tema "Near-surface aquifer":
Articoli di riviste Libri
Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!

Vai alla bibliografia