The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoi...The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoire. To do so, descriptive and multivariate statistical analysis methods with the SOM (Self Organizing Maps) algorithm were applied to the physicochemical parameters of 17 boreholes using the calcite (ISC) and dolomite (ISD) saturation indices. The results obtained have shown that the groundwater in the Angovia mine operating permit area has an average temperature of 27.52°C (long rainy season) and 27.87°C (long dry season) and has an average pH of 7.09 ± 0.35 during the main rainy season and 7.32 ± 0.35 during the main dry season. They are mineralized with an average electrical conductivity of 505.98 ± 302.85 μS/cm during the long rainy season and with 450.33 ± 233.74 μS/cm as average during the long dry season. The main phenomena at the origin of groundwater mineralization are water residence time, oxidation-reduction and surface inflow. The study of the relative age of the water shows that the groundwater in the Angovia mine operating permit area is mainly undersaturated with respect to calcite and dolomite. They are therefore very old in the aquifer with a slow circulation speed during the long rainy season and the long dry season.展开更多
The deep aquifers in Jordan contain non-renewable and fossil groundwater and their extraction is quasi a mining process, which ends in the depletion of these resources. Although aquifers in the majority of groundwater...The deep aquifers in Jordan contain non-renewable and fossil groundwater and their extraction is quasi a mining process, which ends in the depletion of these resources. Although aquifers in the majority of groundwater basins in Jordan are vertically and horizontally interconnected stratification in different water quality horizons with generally increasing water salinity with the depth is observed. Many officials and planners advocate the extraction of deep salty and brackish water to be desalinated and used in household, industrial, and agricultural uses. In this article, the quality of the groundwater in the different deep aquifers and areas in Jordan is discussed. The results of this study show that the consequences of the deep groundwater exploitation are not restricted to depletion of the deep aquifers but also that the overlying fresh groundwater will, due to vertical and horizontal interconnectedness of the different aquifers, percolate down to replace the extracted deep groundwater. This will cause the down-percolating fresh groundwater to become salinized in the deep saline aquifers, which means that extracting the deep brackish and saline groundwater is not only an emptying process of the deep groundwater but also it is an emptying process of the fresh groundwater overlying them. The results allow to conclude that any extraction of the deep groundwater in areas lying to the north of Ras en Naqab Escarpment will have damaging impacts on the fresh groundwater in the overlying fresh groundwater aquifers. This article strongly advises not to extract the deep brackish and saline groundwater, but to conserve that groundwater as a base supporting the overlying fresh groundwater resources, and that will help in protecting the thermal mineralized water springs used in spas originating from these deep aquifers. The increasing water needs of the country can be covered by the desalination of seawater at Aqaba, which is the only viable option for Jordan at present and in the coming decades.展开更多
The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an ef...The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon neutrality.In this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage project.This study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 member.The results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) t.With the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.展开更多
Bagzan mount is located in the Aïr massifs region. This locality, which is constituted only by the granites and volcanic formations, knows the difficulty of water supply that depends on rainfall. This present stu...Bagzan mount is located in the Aïr massifs region. This locality, which is constituted only by the granites and volcanic formations, knows the difficulty of water supply that depends on rainfall. This present study has the objective of fracture mapping that allowed to the fractured aquifer in Bagzan mount. The methodological approach used has a treatment of Digital Elevation Model (DEM imagery), hydrogeological and geological approach in the field. This process allowed us to map the lineaments and elaborate a fracturing map after the validation stage. The fracturing map showed that the fractures network is distributed in the N70°-N80°, N60°-N70°, N50°-N60°, and two secondary directions N90°-N100° and N120°-N140°. These fracturing maps allowed us to have precious information in groundwater research in Bagzan mount, due to their geological and hydrogeological complexity.展开更多
In the A?r massif, and more particularly in the Iférouane area, the basement is flush. Thus, the essential of water resources is contained in the discontinuous aquifers of basement. Indeed, the weathered and crac...In the A?r massif, and more particularly in the Iférouane area, the basement is flush. Thus, the essential of water resources is contained in the discontinuous aquifers of basement. Indeed, the weathered and cracked basement is an excellent reservoir of groundwater. The objective of this study is to determine the areas favorable to establishment of productive drilling in the village of Ebourkoum. A methodological approach based on the combination of remote sensing and geophysics methods was implemented. The fracturing map developed highlighted three main accidents of directions N0° - N10°, N30° - N50° and N130° - N140° in the said locality. The geophysical investigation mainly electrical prospecting has allowed to locate structures with high hydraulic potential below alluvium and alterites. Subsequently, drilling will be carried out in the areas retained.展开更多
According to the requirements for large-scale project implementation, a four-scale and three-level CO_(2)storage potential evaluation method is proposed for saline aquifers in a petroliferous basin in China, consideri...According to the requirements for large-scale project implementation, a four-scale and three-level CO_(2)storage potential evaluation method is proposed for saline aquifers in a petroliferous basin in China, considering geological,engineering and economic factors. The four scales include basin scale, depression scale, play scale and trap scale, and the three levels include theoretical storage capacity, engineering storage capacity, and economic storage capacity. The theoretical storage capacity can be divided into four trapping mechanisms, i.e. structural & stratigraphic trapping, residual trapping, solubility trapping and mineral trapping, depending upon the geological parameters, reservoir conditions and fluid properties in the basin. The engineering storage capacity is affected by the injectivity, storage security pressure, well number, and injection time.The economic storage capacity mainly considers the carbon pricing yield, drilling investment, and operation cost, based on the break-even principle. Application of the method for saline aquifer in the Gaoyou sag of the Subei Basin reveals that the structural & stratigraphic trapping occupies the largest proportion of the theoretical storage capacity, followed by the solubility trapping and the residual trapping, and the mineral trapping takes the lowest proportion. The engineering storage capacity and the economic storage capacity are significantly lower than the theoretical storage capacity when considering the constrains of injectivity, security and economy, respectively accounting for 21.0% and 17.6% of the latter.展开更多
This study aims to make a hydrogeological characterization of the aquifers of the Continental Terminal and the Oligo-Miocene.To do so,an analysis is conducted on the basis of hydrogeological parameters from 172 boreho...This study aims to make a hydrogeological characterization of the aquifers of the Continental Terminal and the Oligo-Miocene.To do so,an analysis is conducted on the basis of hydrogeological parameters from 172 boreholes,10 of which are used for groundwater levels and flows analysis.The results of the statistical analysis of the hydrogeological parameters show that the average flow rate is 42.29 m^(3)/h,the average specific flow rate is 5.96 m^(3)/h/m,and the average transmissivity is 0.024 m^(2)/s.These values highlight the high productivity of aquifers from the Continental Terminal and the Oligo-Miocene.The results of piezometry showed that water flows from the south center to the northwest of Tambacounda where the largest depression is located and could even be the outlet of the system.The groundwater fluctuations between low water level and high water level seasons reveal a rise in the piezometric surface of the aquifers at the scale of the study area.展开更多
Groundwater resources occur in a multi aquifer system in the alluvial coastal plain near Beihai, China. The aquifers receive recharge from precipitation, canal and reservoir infiltration, and discharge through subterr...Groundwater resources occur in a multi aquifer system in the alluvial coastal plain near Beihai, China. The aquifers receive recharge from precipitation, canal and reservoir infiltration, and discharge through subterranean drainage into the sea and through artificial pumping. A quasi three dimensional finite element model has been used to simulate the spatial and temporal distribution of groundwater levels in the aquifers. Various input parameters were considered in the simulation model. A linear optimization model has been developed for groundwater development within the coastal aquifers. The objective function of the model is to maximize the total groundwater pumpage from the confined aquifer. The control of sea water intrusion is examined by the restriction of the water levels at points along the coast and of the pumping rates in coastal management cells. The response matrix used in the optimization model was generated from the simulation model by forecasting drawdown produced by pumping at a unit impulse discharge. Groundwater development can be primarily optimized by the alteration of the pumping rates of the existing wells.展开更多
The semi-arid Sahel regions ofWest Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production.Groundwater quality may be affected b...The semi-arid Sahel regions ofWest Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production.Groundwater quality may be affected by high geogenic arsenic (As) concentrations (>10 μg/L) stemming from the oxidation of sulphide minerals (pyrite,arsenopyrite) in mineralised zones.These aquifers are still little investigated,especially concerning groundwater residence times and the influence of the annual monsoon season on groundwater chemistry.To gain insights on the temporal aspects of As contamination,we have used isotope tracers (noble gases,3H,stable water isotopes (2H,18O)) and performed hydrochemical analyses on groundwater abstracted from tube wells and dug wells in a small study area in southwestern Burkina Faso.Results revealed a great variability in groundwater properties (e.g.redox conditions,As concentrations,water level,residence time) over spatial scales of only a few hundred metres,characteristic of the highly heterogeneous fractured underground.Elevated As levels are found in oxic groundwater of circum-neutral pH and show little relation with any of the measured parameters.Arsenic concentrations are relatively stable over the course of the year,with little effect seen by the monsoon.Groundwater residence time does not seem to have an influence on As concentrations,as elevated As can be found both in groundwater with short (<50 a) and long (>10^3 a) residence times as indicated by 3He/4He ratios spanning three orders of magnitude.These results support the hypothesis that the proximity to mineralised zones is the most crucial factor controlling As concentrations in the observed redox/pH conditions.The existence of very old water portions with residence times >10^3 years already at depths of <50 m b.g.l.is a new finding for the shallow fractured bedrock aquifers of Burkina Faso,suggesting that overexploitation of these relatively low-yielding aquifers may be an issue in the future.展开更多
The study illustrates the critical role of accurate geological structural mapping to delineate crystalline aquifer zones more prone to high health risk due to elevated dissolved As in drinking wells.The analysis revis...The study illustrates the critical role of accurate geological structural mapping to delineate crystalline aquifer zones more prone to high health risk due to elevated dissolved As in drinking wells.The analysis revisits the results from more than 1200 groundwater samples collected over ten years from domestic wells across the Tampere region (Finland).It is demonstrated that the highest dissolved As concentrations in the region (up to 2230 mg/L) are exclusively found near major faults and deformation zones (FDZs) detected via geophysical and geological surveys,and that a clear correlation exists between dissolved concentrations and the distance from the FDZs (r).Almost all values exceeding the drinking water limit (10 mg/L) occur at r < 8 km,while concentrations above 100 mg/L occur at r < 4 km.Solidphase As concentrations in bedrock show less dependency on FDZ than aqueous concentrations.This behavior is explained considering different mechanisms,which include enhanced sulfide oxidation and fracture connectivity,promoting preferential transport of dissolved As to FDZs and mixing of waters from different redox zones,mobilizing preferentially As(III) or As(V).Fe hydro-oxides may also precipitate/ dissolve preferentially because of FDZs,while residence time may influence the contact time between water and As-bearing minerals.It is concluded that the accurate mapping of FDZs,and in general of structural geology,provides an important preliminary information to identify where localized,sitespecific characterization of hydrogeology and geochemistry is more urgent to reduce As-related health risk from groundwater intake.展开更多
The present work provides hydrochemical and stable isotope data and their interpretations for 54 springs and 20 wells, monitored from 2002 to 2006, in the Southern Latium region of Central Italy to identify flow paths...The present work provides hydrochemical and stable isotope data and their interpretations for 54 springs and 20 wells, monitored from 2002 to 2006, in the Southern Latium region of Central Italy to identify flow paths, recharge areas and hydrochemical processes governing the evolution of groundwater in this region. The hydrogeological conceptual model of the carbonate aquifers of southern Latium was based on environmental isotopic and hydrochemical investigation techniques to characterize and model these aquifer systems with the aim of achieving proper management and protection of these important resources. Most of the spring samples, issuing from Lepini, Ausoni and Aurunci Mts., are characterized as Ca-Mg-HCO3 water type, however, some samples show a composition of Na-Cl and mixed Ca-Na-HCO3-Cl waters. Groundwater samples from Pontina Plain are mostly characterized by Na-Cl and Ca-Cl type waters. Geochemical modeling and saturation index computation of the Lepini, Ausoni Aurunci springs and Pontina Plain wells shows an interaction with carbonate rocks. Most of the spring and well water samples were saturated with respect to calcite and dolomite, however all sampled waters were undersaturated with respect to gypsum and halite. The relationship between δ18O and δ2H, for spring and well water samples, shows shifts of both the slope and the deuterium excess when compared to the world meteoric (WMWL) and central Italy meteoric (CIMWL) water lines. The deviation of data points from the meteoric lines can be attributed to evaporation both during the falling of the rain and by run-off on the ground surface before infiltration. Most springs and wells have a deuterium excess above 10 ‰ suggesting the precipitation in the groundwater comes from the Mediterranean sector. On the basis of local isotopic gradients, in combination with topographic and geologic criteria, four recharge areas were identified in the Aurunci Mountains. In Pontina Plain, the elevations of the recharging areas suggest that the Lepini carbonate aquifers are feeding them.展开更多
In the basement of southwestern Niger, weathering and fractured zones concentrate most of the groundwater. This study focuses on fractured media and aims to identify areas of productivity in this aquifer to improve th...In the basement of southwestern Niger, weathering and fractured zones concentrate most of the groundwater. This study focuses on fractured media and aims to identify areas of productivity in this aquifer to improve the region’s water coverage. The cartographic approach developed made it possible to establish synthetic maps based on multi-criteria analysis. The hydrogeological parameters selected include fracturing data, drainage system, slope and piezometric level as well as shallow and deep lithology. The choice of these criteria is based on their physical meaning but also on the availability of data. The integration of all the criteria in a GIS allowed to generate maps of recharge and potential productivity of fractured aquifers in the area. The validation of these thematic maps with independent data confirms their utility as reference standards for accessibility for future resource exploitation. Like any spatialization tool, potential recharge maps will provide valuable information about areas where infiltration is more important, and help control and manage risk zoning. The upward evacuation effect is even more prominent along the lineaments, faults or fractures: thus, to avoid possible pollution and to locate the future hydraulic structures, the analysis of the potential recharge zones remains necessary. The potential productivity index map, in addition to the very punctual sites identified by the fracturing study, made it possible to define areas of high potential productivity.展开更多
On December 26,2004,the Indian Ocean tsunami waves hit Sri Lanka resulting in the devastation of the coastal aquifers from saltwater contamination.In an attempt to speed up the cleaning process of the contaminated wat...On December 26,2004,the Indian Ocean tsunami waves hit Sri Lanka resulting in the devastation of the coastal aquifers from saltwater contamination.In an attempt to speed up the cleaning process of the contaminated water in wells,large-scale and intensive campaigns went into cleaning and rehabilitating wells through pumping out saline water(physical cleansing). However,it was unclear whether these attempts improved the well-water quality,especially in terms of salinity due to density driven flow and solute transport phenomenon.Changes in water quality of a sand aquifer on the east coast of Sri Lanka owing to the December 26,2004 tsunami and展开更多
Kalpitiya peninsular aquifer which is one of the highly productive and extremely permeable quarternary sand aquifers in Sri Lanka is heavily used for irrigation purposes of agricultural activities for decades.This stu...Kalpitiya peninsular aquifer which is one of the highly productive and extremely permeable quarternary sand aquifers in Sri Lanka is heavily used for irrigation purposes of agricultural activities for decades.This study focuses on the spatial and temporal nutrient pollution of groundwater of shallow aquifer of Kalpitiya peninsula and nitrate,phosphate, major cations and some physical parameters were measured during one year period covering two展开更多
The rapid increase of urban population in coastal areas of developing countries is nowadays a widespread phenomenon that has several environmental, economical and social consequences.Internal migration, spread of info...The rapid increase of urban population in coastal areas of developing countries is nowadays a widespread phenomenon that has several environmental, economical and social consequences.Internal migration, spread of informal suburban settlements,lack of adequate sanitation,increase in water extraction。展开更多
The karst aquifers are the most important water resources in Southwest China,where displays the most continuous bare karst around the world and hold about 100 million people.With the rapid expansion of the urbanizatio...The karst aquifers are the most important water resources in Southwest China,where displays the most continuous bare karst around the world and hold about 100 million people.With the rapid expansion of the urbanization,development of the industry and agriculture,the groundwater quality has been degraded.Mineralization of the karst groundwater increases because of development of intensive agriculture.Concentrations of nitrate and sulphate increase notably as a result of the large amount of chemical fertilizer used in agriculture.Waste gas, waste water and waste residues produced in the processes of industrialization and urbanization cause groundwater acidification and an increase of pollutants such as nitrogen,phosphate,chloride,展开更多
As numerical modeling is an effective tool for managing groundwater resources and predicting future responses, in this study, the author has intended to assess groundwater flow through Modflow 6 and Model Muse into Po...As numerical modeling is an effective tool for managing groundwater resources and predicting future responses, in this study, the author has intended to assess groundwater flow through Modflow 6 and Model Muse into Pointe-Noire coastal aquifers. The results showed that the fourth scenario has the biggest effect on the drawdown and seawater intrusion extent. Different parameters including evapotranspiration, recharge, model boundary, etc. were adjusted to run the model. The fourth scenario with the highest pumping rate value caused a slight increase of head values over the values simulated.展开更多
The hydraulic properties of deeper Coastal Plain Sands, which form the main aquifer in the Niger Delta, were investigated around Eleme, Rivers State. The intent was to find out if frequent well failure was as a result...The hydraulic properties of deeper Coastal Plain Sands, which form the main aquifer in the Niger Delta, were investigated around Eleme, Rivers State. The intent was to find out if frequent well failure was as a result of the aquifer not having enough transmitting capacity to sustain the huge withdrawal necessary for Eleme and its environs where demand for groundwater withdrawal is very high because Eleme axis serves as a major industrial axis of River State or whether the frequent well failure was due to inefficient well construction practice. Constant discharge pumping tests were conducted in 8 deep borehole (250 - 310 m). Data generated during the test were analysed using Cooper-Jacob’s straight line method. The calculated transmissivity of the aquifers ranged from 1324 m2/day - 5815 m2/day. These values when compared with transmissivity values elsewhere indicate that the aquifers in the study area have excellent water yielding properties, plotting within the range of “Very Good” in water transmitting capacity scale. Coefficient of permeability ranged from 13.65 m/d - 59.9 m/d. Coefficient of Storage ranged from 28.2 × 10-5 - 29.1 × 10-5 while the Specific capacities of the wells ranged from 48.75 3 - 78.13 m3/d/m. It is concluded that the deep aquifers of the Niger Delta do possess the capacity to produce and sustain large groundwater withdrawal. It is further recommended that competent drilling contractors be engaged in deep well construction in the area.展开更多
Groundwater vulnerability is an overlay method that is used to determine the ability of pollutants to penetrate to the target aquifer and to harm it. This method helps decision makers by shedding light on pollution ar...Groundwater vulnerability is an overlay method that is used to determine the ability of pollutants to penetrate to the target aquifer and to harm it. This method helps decision makers by shedding light on pollution areas expected to pollute groundwater aquifers as caused by human activities on the ground surface. In Jordan, groundwater is the main water resource the country uses to match its demand. The groundwater basins in Jordan are divided into 12 major basins. Some basins are rechargeable and other basins are fossil. Many basins are over exploited. Amman Zarqa basin is a clear example for this case. Others are saline just like Azraq basin and the rest is expected to be affected by the growing demand for agricultural, municipal and industrial activities. In this study, a groundwater vulnerability map was produced for Jordan using DRASTIC index to study the vulnerability of the shallow aquifers throughout the country. The map shows different vulnerability classes ranging from low to very high reflecting the environmental, hydrological and hydrogeological settings of the groundwater and its recharge ability. The resulted map shows wide variation in groundwater vulnerability in different sites in Jordan. Areas with higher vulnerability are those with friable aquifer materials and shallow groundwater depths. Medium and low vulnerability classes are exist too because of the variations of the environmental settings within the targeted areas.展开更多
文摘The main objective of this study is to determine the hydrogeochemical specificities of the groundwater of the Angovia mine operating permit, located in the Yaouré mountains in the center-west of Côte d’Ivoire. To do so, descriptive and multivariate statistical analysis methods with the SOM (Self Organizing Maps) algorithm were applied to the physicochemical parameters of 17 boreholes using the calcite (ISC) and dolomite (ISD) saturation indices. The results obtained have shown that the groundwater in the Angovia mine operating permit area has an average temperature of 27.52°C (long rainy season) and 27.87°C (long dry season) and has an average pH of 7.09 ± 0.35 during the main rainy season and 7.32 ± 0.35 during the main dry season. They are mineralized with an average electrical conductivity of 505.98 ± 302.85 μS/cm during the long rainy season and with 450.33 ± 233.74 μS/cm as average during the long dry season. The main phenomena at the origin of groundwater mineralization are water residence time, oxidation-reduction and surface inflow. The study of the relative age of the water shows that the groundwater in the Angovia mine operating permit area is mainly undersaturated with respect to calcite and dolomite. They are therefore very old in the aquifer with a slow circulation speed during the long rainy season and the long dry season.
文摘The deep aquifers in Jordan contain non-renewable and fossil groundwater and their extraction is quasi a mining process, which ends in the depletion of these resources. Although aquifers in the majority of groundwater basins in Jordan are vertically and horizontally interconnected stratification in different water quality horizons with generally increasing water salinity with the depth is observed. Many officials and planners advocate the extraction of deep salty and brackish water to be desalinated and used in household, industrial, and agricultural uses. In this article, the quality of the groundwater in the different deep aquifers and areas in Jordan is discussed. The results of this study show that the consequences of the deep groundwater exploitation are not restricted to depletion of the deep aquifers but also that the overlying fresh groundwater will, due to vertical and horizontal interconnectedness of the different aquifers, percolate down to replace the extracted deep groundwater. This will cause the down-percolating fresh groundwater to become salinized in the deep saline aquifers, which means that extracting the deep brackish and saline groundwater is not only an emptying process of the deep groundwater but also it is an emptying process of the fresh groundwater overlying them. The results allow to conclude that any extraction of the deep groundwater in areas lying to the north of Ras en Naqab Escarpment will have damaging impacts on the fresh groundwater in the overlying fresh groundwater aquifers. This article strongly advises not to extract the deep brackish and saline groundwater, but to conserve that groundwater as a base supporting the overlying fresh groundwater resources, and that will help in protecting the thermal mineralized water springs used in spas originating from these deep aquifers. The increasing water needs of the country can be covered by the desalination of seawater at Aqaba, which is the only viable option for Jordan at present and in the coming decades.
基金funded by the Top 10 key scientific and technological projects of CHN Energy in 2021 entitled Research and Demonstration of Technology for Carbon Dioxide Capture and Energy Recycling Utilization(GJNYKJ[2021]No.128,No.:GJNY-21-51)the Carbon Neutrality College(Yulin)Northwest University project entitled Design and research of large-scale CCUS cluster construction in Yulin area,Shaanxi Province(YL2022-38-01).
文摘The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos Basin.The geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon neutrality.In this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage project.This study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 member.The results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) t.With the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.
文摘Bagzan mount is located in the Aïr massifs region. This locality, which is constituted only by the granites and volcanic formations, knows the difficulty of water supply that depends on rainfall. This present study has the objective of fracture mapping that allowed to the fractured aquifer in Bagzan mount. The methodological approach used has a treatment of Digital Elevation Model (DEM imagery), hydrogeological and geological approach in the field. This process allowed us to map the lineaments and elaborate a fracturing map after the validation stage. The fracturing map showed that the fractures network is distributed in the N70°-N80°, N60°-N70°, N50°-N60°, and two secondary directions N90°-N100° and N120°-N140°. These fracturing maps allowed us to have precious information in groundwater research in Bagzan mount, due to their geological and hydrogeological complexity.
文摘In the A?r massif, and more particularly in the Iférouane area, the basement is flush. Thus, the essential of water resources is contained in the discontinuous aquifers of basement. Indeed, the weathered and cracked basement is an excellent reservoir of groundwater. The objective of this study is to determine the areas favorable to establishment of productive drilling in the village of Ebourkoum. A methodological approach based on the combination of remote sensing and geophysics methods was implemented. The fracturing map developed highlighted three main accidents of directions N0° - N10°, N30° - N50° and N130° - N140° in the said locality. The geophysical investigation mainly electrical prospecting has allowed to locate structures with high hydraulic potential below alluvium and alterites. Subsequently, drilling will be carried out in the areas retained.
基金Supported by the Intergovernmental International Scientific and Technological Innovation Project (2022YFE0115800)Sinopec CCUS Project (P21075)。
文摘According to the requirements for large-scale project implementation, a four-scale and three-level CO_(2)storage potential evaluation method is proposed for saline aquifers in a petroliferous basin in China, considering geological,engineering and economic factors. The four scales include basin scale, depression scale, play scale and trap scale, and the three levels include theoretical storage capacity, engineering storage capacity, and economic storage capacity. The theoretical storage capacity can be divided into four trapping mechanisms, i.e. structural & stratigraphic trapping, residual trapping, solubility trapping and mineral trapping, depending upon the geological parameters, reservoir conditions and fluid properties in the basin. The engineering storage capacity is affected by the injectivity, storage security pressure, well number, and injection time.The economic storage capacity mainly considers the carbon pricing yield, drilling investment, and operation cost, based on the break-even principle. Application of the method for saline aquifer in the Gaoyou sag of the Subei Basin reveals that the structural & stratigraphic trapping occupies the largest proportion of the theoretical storage capacity, followed by the solubility trapping and the residual trapping, and the mineral trapping takes the lowest proportion. The engineering storage capacity and the economic storage capacity are significantly lower than the theoretical storage capacity when considering the constrains of injectivity, security and economy, respectively accounting for 21.0% and 17.6% of the latter.
文摘This study aims to make a hydrogeological characterization of the aquifers of the Continental Terminal and the Oligo-Miocene.To do so,an analysis is conducted on the basis of hydrogeological parameters from 172 boreholes,10 of which are used for groundwater levels and flows analysis.The results of the statistical analysis of the hydrogeological parameters show that the average flow rate is 42.29 m^(3)/h,the average specific flow rate is 5.96 m^(3)/h/m,and the average transmissivity is 0.024 m^(2)/s.These values highlight the high productivity of aquifers from the Continental Terminal and the Oligo-Miocene.The results of piezometry showed that water flows from the south center to the northwest of Tambacounda where the largest depression is located and could even be the outlet of the system.The groundwater fluctuations between low water level and high water level seasons reveal a rise in the piezometric surface of the aquifers at the scale of the study area.
基金This paper is partially supported by the Fund for Young Geologists in the Ministry of Geology and Mineral Resources of China(
文摘Groundwater resources occur in a multi aquifer system in the alluvial coastal plain near Beihai, China. The aquifers receive recharge from precipitation, canal and reservoir infiltration, and discharge through subterranean drainage into the sea and through artificial pumping. A quasi three dimensional finite element model has been used to simulate the spatial and temporal distribution of groundwater levels in the aquifers. Various input parameters were considered in the simulation model. A linear optimization model has been developed for groundwater development within the coastal aquifers. The objective function of the model is to maximize the total groundwater pumpage from the confined aquifer. The control of sea water intrusion is examined by the restriction of the water levels at points along the coast and of the pumping rates in coastal management cells. The response matrix used in the optimization model was generated from the simulation model by forecasting drawdown produced by pumping at a unit impulse discharge. Groundwater development can be primarily optimized by the alteration of the pumping rates of the existing wells.
基金provided by the Swiss Agency for Development and Cooperation (SDC) through the "Programme 3E" (contract no.81016359)the Information Management System on Geogenic Contaminants, GAP (contract no.81025383)
文摘The semi-arid Sahel regions ofWest Africa rely heavily on groundwater from shallow to moderately deep (<100 m b.g.l.) crystalline bedrock aquifers for drinking water production.Groundwater quality may be affected by high geogenic arsenic (As) concentrations (>10 μg/L) stemming from the oxidation of sulphide minerals (pyrite,arsenopyrite) in mineralised zones.These aquifers are still little investigated,especially concerning groundwater residence times and the influence of the annual monsoon season on groundwater chemistry.To gain insights on the temporal aspects of As contamination,we have used isotope tracers (noble gases,3H,stable water isotopes (2H,18O)) and performed hydrochemical analyses on groundwater abstracted from tube wells and dug wells in a small study area in southwestern Burkina Faso.Results revealed a great variability in groundwater properties (e.g.redox conditions,As concentrations,water level,residence time) over spatial scales of only a few hundred metres,characteristic of the highly heterogeneous fractured underground.Elevated As levels are found in oxic groundwater of circum-neutral pH and show little relation with any of the measured parameters.Arsenic concentrations are relatively stable over the course of the year,with little effect seen by the monsoon.Groundwater residence time does not seem to have an influence on As concentrations,as elevated As can be found both in groundwater with short (<50 a) and long (>10^3 a) residence times as indicated by 3He/4He ratios spanning three orders of magnitude.These results support the hypothesis that the proximity to mineralised zones is the most crucial factor controlling As concentrations in the observed redox/pH conditions.The existence of very old water portions with residence times >10^3 years already at depths of <50 m b.g.l.is a new finding for the shallow fractured bedrock aquifers of Burkina Faso,suggesting that overexploitation of these relatively low-yielding aquifers may be an issue in the future.
基金supported by GTK (internal funding)EU Life-Environment Program (RAMAS project)EU Life+Project focusing on natural aggregate resources (ASROCKS)
文摘The study illustrates the critical role of accurate geological structural mapping to delineate crystalline aquifer zones more prone to high health risk due to elevated dissolved As in drinking wells.The analysis revisits the results from more than 1200 groundwater samples collected over ten years from domestic wells across the Tampere region (Finland).It is demonstrated that the highest dissolved As concentrations in the region (up to 2230 mg/L) are exclusively found near major faults and deformation zones (FDZs) detected via geophysical and geological surveys,and that a clear correlation exists between dissolved concentrations and the distance from the FDZs (r).Almost all values exceeding the drinking water limit (10 mg/L) occur at r < 8 km,while concentrations above 100 mg/L occur at r < 4 km.Solidphase As concentrations in bedrock show less dependency on FDZ than aqueous concentrations.This behavior is explained considering different mechanisms,which include enhanced sulfide oxidation and fracture connectivity,promoting preferential transport of dissolved As to FDZs and mixing of waters from different redox zones,mobilizing preferentially As(III) or As(V).Fe hydro-oxides may also precipitate/ dissolve preferentially because of FDZs,while residence time may influence the contact time between water and As-bearing minerals.It is concluded that the accurate mapping of FDZs,and in general of structural geology,provides an important preliminary information to identify where localized,sitespecific characterization of hydrogeology and geochemistry is more urgent to reduce As-related health risk from groundwater intake.
文摘The present work provides hydrochemical and stable isotope data and their interpretations for 54 springs and 20 wells, monitored from 2002 to 2006, in the Southern Latium region of Central Italy to identify flow paths, recharge areas and hydrochemical processes governing the evolution of groundwater in this region. The hydrogeological conceptual model of the carbonate aquifers of southern Latium was based on environmental isotopic and hydrochemical investigation techniques to characterize and model these aquifer systems with the aim of achieving proper management and protection of these important resources. Most of the spring samples, issuing from Lepini, Ausoni and Aurunci Mts., are characterized as Ca-Mg-HCO3 water type, however, some samples show a composition of Na-Cl and mixed Ca-Na-HCO3-Cl waters. Groundwater samples from Pontina Plain are mostly characterized by Na-Cl and Ca-Cl type waters. Geochemical modeling and saturation index computation of the Lepini, Ausoni Aurunci springs and Pontina Plain wells shows an interaction with carbonate rocks. Most of the spring and well water samples were saturated with respect to calcite and dolomite, however all sampled waters were undersaturated with respect to gypsum and halite. The relationship between δ18O and δ2H, for spring and well water samples, shows shifts of both the slope and the deuterium excess when compared to the world meteoric (WMWL) and central Italy meteoric (CIMWL) water lines. The deviation of data points from the meteoric lines can be attributed to evaporation both during the falling of the rain and by run-off on the ground surface before infiltration. Most springs and wells have a deuterium excess above 10 ‰ suggesting the precipitation in the groundwater comes from the Mediterranean sector. On the basis of local isotopic gradients, in combination with topographic and geologic criteria, four recharge areas were identified in the Aurunci Mountains. In Pontina Plain, the elevations of the recharging areas suggest that the Lepini carbonate aquifers are feeding them.
文摘In the basement of southwestern Niger, weathering and fractured zones concentrate most of the groundwater. This study focuses on fractured media and aims to identify areas of productivity in this aquifer to improve the region’s water coverage. The cartographic approach developed made it possible to establish synthetic maps based on multi-criteria analysis. The hydrogeological parameters selected include fracturing data, drainage system, slope and piezometric level as well as shallow and deep lithology. The choice of these criteria is based on their physical meaning but also on the availability of data. The integration of all the criteria in a GIS allowed to generate maps of recharge and potential productivity of fractured aquifers in the area. The validation of these thematic maps with independent data confirms their utility as reference standards for accessibility for future resource exploitation. Like any spatialization tool, potential recharge maps will provide valuable information about areas where infiltration is more important, and help control and manage risk zoning. The upward evacuation effect is even more prominent along the lineaments, faults or fractures: thus, to avoid possible pollution and to locate the future hydraulic structures, the analysis of the potential recharge zones remains necessary. The potential productivity index map, in addition to the very punctual sites identified by the fracturing study, made it possible to define areas of high potential productivity.
文摘On December 26,2004,the Indian Ocean tsunami waves hit Sri Lanka resulting in the devastation of the coastal aquifers from saltwater contamination.In an attempt to speed up the cleaning process of the contaminated water in wells,large-scale and intensive campaigns went into cleaning and rehabilitating wells through pumping out saline water(physical cleansing). However,it was unclear whether these attempts improved the well-water quality,especially in terms of salinity due to density driven flow and solute transport phenomenon.Changes in water quality of a sand aquifer on the east coast of Sri Lanka owing to the December 26,2004 tsunami and
文摘Kalpitiya peninsular aquifer which is one of the highly productive and extremely permeable quarternary sand aquifers in Sri Lanka is heavily used for irrigation purposes of agricultural activities for decades.This study focuses on the spatial and temporal nutrient pollution of groundwater of shallow aquifer of Kalpitiya peninsula and nitrate,phosphate, major cations and some physical parameters were measured during one year period covering two
文摘The rapid increase of urban population in coastal areas of developing countries is nowadays a widespread phenomenon that has several environmental, economical and social consequences.Internal migration, spread of informal suburban settlements,lack of adequate sanitation,increase in water extraction。
文摘The karst aquifers are the most important water resources in Southwest China,where displays the most continuous bare karst around the world and hold about 100 million people.With the rapid expansion of the urbanization,development of the industry and agriculture,the groundwater quality has been degraded.Mineralization of the karst groundwater increases because of development of intensive agriculture.Concentrations of nitrate and sulphate increase notably as a result of the large amount of chemical fertilizer used in agriculture.Waste gas, waste water and waste residues produced in the processes of industrialization and urbanization cause groundwater acidification and an increase of pollutants such as nitrogen,phosphate,chloride,
文摘As numerical modeling is an effective tool for managing groundwater resources and predicting future responses, in this study, the author has intended to assess groundwater flow through Modflow 6 and Model Muse into Pointe-Noire coastal aquifers. The results showed that the fourth scenario has the biggest effect on the drawdown and seawater intrusion extent. Different parameters including evapotranspiration, recharge, model boundary, etc. were adjusted to run the model. The fourth scenario with the highest pumping rate value caused a slight increase of head values over the values simulated.
文摘The hydraulic properties of deeper Coastal Plain Sands, which form the main aquifer in the Niger Delta, were investigated around Eleme, Rivers State. The intent was to find out if frequent well failure was as a result of the aquifer not having enough transmitting capacity to sustain the huge withdrawal necessary for Eleme and its environs where demand for groundwater withdrawal is very high because Eleme axis serves as a major industrial axis of River State or whether the frequent well failure was due to inefficient well construction practice. Constant discharge pumping tests were conducted in 8 deep borehole (250 - 310 m). Data generated during the test were analysed using Cooper-Jacob’s straight line method. The calculated transmissivity of the aquifers ranged from 1324 m2/day - 5815 m2/day. These values when compared with transmissivity values elsewhere indicate that the aquifers in the study area have excellent water yielding properties, plotting within the range of “Very Good” in water transmitting capacity scale. Coefficient of permeability ranged from 13.65 m/d - 59.9 m/d. Coefficient of Storage ranged from 28.2 × 10-5 - 29.1 × 10-5 while the Specific capacities of the wells ranged from 48.75 3 - 78.13 m3/d/m. It is concluded that the deep aquifers of the Niger Delta do possess the capacity to produce and sustain large groundwater withdrawal. It is further recommended that competent drilling contractors be engaged in deep well construction in the area.
文摘Groundwater vulnerability is an overlay method that is used to determine the ability of pollutants to penetrate to the target aquifer and to harm it. This method helps decision makers by shedding light on pollution areas expected to pollute groundwater aquifers as caused by human activities on the ground surface. In Jordan, groundwater is the main water resource the country uses to match its demand. The groundwater basins in Jordan are divided into 12 major basins. Some basins are rechargeable and other basins are fossil. Many basins are over exploited. Amman Zarqa basin is a clear example for this case. Others are saline just like Azraq basin and the rest is expected to be affected by the growing demand for agricultural, municipal and industrial activities. In this study, a groundwater vulnerability map was produced for Jordan using DRASTIC index to study the vulnerability of the shallow aquifers throughout the country. The map shows different vulnerability classes ranging from low to very high reflecting the environmental, hydrological and hydrogeological settings of the groundwater and its recharge ability. The resulted map shows wide variation in groundwater vulnerability in different sites in Jordan. Areas with higher vulnerability are those with friable aquifer materials and shallow groundwater depths. Medium and low vulnerability classes are exist too because of the variations of the environmental settings within the targeted areas.
