Rare earth element （REE） concentrations were measured by ICP-MS for groundwater collected from deep seated Taiyuan Fm limestone aquifer （from -400 to -530 m） in Renlou Coal Mine, northern Anhui Province, China. It...Rare earth element （REE） concentrations were measured by ICP-MS for groundwater collected from deep seated Taiyuan Fm limestone aquifer （from -400 to -530 m） in Renlou Coal Mine, northern Anhui Province, China. It can be concluded that the groundwater is warm （34.0-37.2 ℃） C1-Ca, Na type water with circum-neutral pH （7.35-8.28） and high total dissolved solids （TDS, 1 746-2 849 mg/L）. The groundwater exhibits heavy REEs enrichment relative to light REEs compared with Post Archean Average Shale （PAAS）, as well as their aquifer rocks （limestone）. The enrichment of REEs is considered to be controlled by terrigeneous materials （e.g. zircon） in aquifer rocks, whereas the fractionation of REEs is controlled by marine derived materials （e.g. calcite）, to a less extent, terrigeneous materials and inorganic complexation. The Ce anomalies normalized to PAAS and aquifer rocks are weak, which probably reflects the signature of the aquifer rock rather than redox conditions or pH. The similarities of REE patterns between groundwater and aquifer rocks imply that aquifer rocks play important roles in controlling the REE characteristics of groundwater, and then provide a probability for discrimination of groundwater sources by using REEs.展开更多
The variation characteristics of aquifer parameters,induced by groundwater source heat pump(GWSHP) operation under variable flow,were theoretically analyzed through a case study,in which the characteristics of buildin...The variation characteristics of aquifer parameters,induced by groundwater source heat pump(GWSHP) operation under variable flow,were theoretically analyzed through a case study,in which the characteristics of building air conditioning load were considered.The results,compared with the constant flow operation,indicate that the influence on the variations of porosity,hydraulic conductivity and confined water head is decreased by 48%,51% and 71%,respectively,under variable flow operation.The security of variable flow operation is superior to that of constant flow.It is also concluded that the climate region and function of the buildings are primary factors which affect the suitability of variable flow operation in GWSHP.展开更多
By means of the pore-level simulation, the characteristics of gas-water flow and gas-water distribution during the alternative displacement of gas and water were observed directly from etched-glass micromodel. The res...By means of the pore-level simulation, the characteristics of gas-water flow and gas-water distribution during the alternative displacement of gas and water were observed directly from etched-glass micromodel. The results show that gas-water distribution styles are divided into continuous phase type and separate phase type. The water lock exists in pore and throat during the process of gas-water displacement, and it reduces the gas flow-rate and has some effects on the recovery efficiency during the operation of gas storage. According to the experimental results of aquifer gas storage in X area, the differences in available extent among reservoirs are significant, and the availability of pore space is 33% 45%.展开更多
Groundwater is a finite resource which is being overexploited due to increase in demand over the years leading to decrease in its potentiality.As it is known that ground water is the only major source of drinking wate...Groundwater is a finite resource which is being overexploited due to increase in demand over the years leading to decrease in its potentiality.As it is known that ground water is the only major source of drinking water for both urban and rural India its proper management is very essential for its sustainability. In the present study,DRASTIC model is展开更多
The impact of population pressure has been observed on several systems,groundwater resource is one among them.Mismanagement and over-exploitation has not only caused the decline of groundwater levels but also causes d...The impact of population pressure has been observed on several systems,groundwater resource is one among them.Mismanagement and over-exploitation has not only caused the decline of groundwater levels but also causes deterioration in water quality. Fluoride is one of such parameters where impact of over exploitation has been observed.Fluoride is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
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
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 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
This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeabilit...This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeability and strength of jet-grouted materials are considered.Subsequently,a calculation example is analyzed and discussed.Results show that“tension failure”mechanism is a major concern for the structural failure during a design of MWSBs.The maximum allowable seepage discharge is a crucial index for the design of MWSBs,which has a significant influence on determining the design parameters of MWSBs.Compared with the design procedure for MWSBs that is proposed in this paper,the design parameters of MWSBs determined by the stability equilibrium and seepage stability equilibrium approaches are conservative due to the fact that it fails to consider the permeability or strength of jet-grouted materials that makes a contribution to the structural safety.Based on the proposed design method,the ranges of both the thickness and depth of MWSBs for a case history of subway excavation in Fuzhou,China were determined.Finally,field pumping test results showed that the water-tightness performance of MWSBs performed at site was quite well.展开更多
The development and growing population has resulted in the increasing demand for potable water in tiny atolls of Lakshadweep group,off the western coast of India.In recent years,the groundwater quality,in such atolls,...The development and growing population has resulted in the increasing demand for potable water in tiny atolls of Lakshadweep group,off the western coast of India.In recent years,the groundwater quality,in such atolls,has been deteriorated due to indiscriminate exploitation of groundwater to meet the demand.Thus arranging a sustainable supply of groundwater has become the most challenging task on these tiny atolls for the survival of human life. Groundwater floats in the form of thin lens,which展开更多
The Turonian aquifer of the Tadla’s basin shows at present a pronounced reduction of its hydraulic potential linked to overexploitation and deficiency of effective rains.In order to make an evaluation of the resource...The Turonian aquifer of the Tadla’s basin shows at present a pronounced reduction of its hydraulic potential linked to overexploitation and deficiency of effective rains.In order to make an evaluation of the resources of water and implant the exploitation’s drillings of groundwater,a geophysical study by展开更多
In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confine...In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face.This study employed the finite element method(FEM)to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer.Subsequently,a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure,incorporating various influencing factors.The analysis yields the following conclusions:1)The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable;2)The limit support pressure increases approximately linearly with the pressure head,shield tunnel diameter,and tunnel burial depth.And inversely proportional to the thickness of the impermeable layer,soil cohesion and internal friction angle;3)Through an engineering case study analysis,the results align well with those obtained from traditional theoretical methods,thereby validating the rationality of the equations proposed in this paper.Furthermore,the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness.It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling,thus better reflecting engineering reality.展开更多
The seismoelectrical method(also called the Electroseismic method or seismo-electric) is based on the generation of electromagnetic fields in soils and rocks by seismic waves.Although the method is not reported to det...The seismoelectrical method(also called the Electroseismic method or seismo-electric) is based on the generation of electromagnetic fields in soils and rocks by seismic waves.Although the method is not reported to detect groundwater flow,it does measure the hydraulic conductivity,which is related to permeability and,therefore,to the potential of groundwater flow.Electroseismic technology is an effective tool for the siting of water wells。展开更多
基金Project(40873015) supported by the National Natural Science Foundation of ChinaProject(08010302062) supported by the Eleventh Five-year Scientific and Technological Program of Anhui Province,China
文摘Rare earth element （REE） concentrations were measured by ICP-MS for groundwater collected from deep seated Taiyuan Fm limestone aquifer （from -400 to -530 m） in Renlou Coal Mine, northern Anhui Province, China. It can be concluded that the groundwater is warm （34.0-37.2 ℃） C1-Ca, Na type water with circum-neutral pH （7.35-8.28） and high total dissolved solids （TDS, 1 746-2 849 mg/L）. The groundwater exhibits heavy REEs enrichment relative to light REEs compared with Post Archean Average Shale （PAAS）, as well as their aquifer rocks （limestone）. The enrichment of REEs is considered to be controlled by terrigeneous materials （e.g. zircon） in aquifer rocks, whereas the fractionation of REEs is controlled by marine derived materials （e.g. calcite）, to a less extent, terrigeneous materials and inorganic complexation. The Ce anomalies normalized to PAAS and aquifer rocks are weak, which probably reflects the signature of the aquifer rock rather than redox conditions or pH. The similarities of REE patterns between groundwater and aquifer rocks imply that aquifer rocks play important roles in controlling the REE characteristics of groundwater, and then provide a probability for discrimination of groundwater sources by using REEs.
基金Project(2006BAJ01B05) supported by the National Science and Technology Pillar Program during the 11th Five-Year Plane Period
文摘The variation characteristics of aquifer parameters,induced by groundwater source heat pump(GWSHP) operation under variable flow,were theoretically analyzed through a case study,in which the characteristics of building air conditioning load were considered.The results,compared with the constant flow operation,indicate that the influence on the variations of porosity,hydraulic conductivity and confined water head is decreased by 48%,51% and 71%,respectively,under variable flow operation.The security of variable flow operation is superior to that of constant flow.It is also concluded that the climate region and function of the buildings are primary factors which affect the suitability of variable flow operation in GWSHP.
基金Project(2011ZX05013-002)supported by National Science and Technology Major Projects of China
文摘By means of the pore-level simulation, the characteristics of gas-water flow and gas-water distribution during the alternative displacement of gas and water were observed directly from etched-glass micromodel. The results show that gas-water distribution styles are divided into continuous phase type and separate phase type. The water lock exists in pore and throat during the process of gas-water displacement, and it reduces the gas flow-rate and has some effects on the recovery efficiency during the operation of gas storage. According to the experimental results of aquifer gas storage in X area, the differences in available extent among reservoirs are significant, and the availability of pore space is 33% 45%.
文摘Groundwater is a finite resource which is being overexploited due to increase in demand over the years leading to decrease in its potentiality.As it is known that ground water is the only major source of drinking water for both urban and rural India its proper management is very essential for its sustainability. In the present study,DRASTIC model is
文摘The impact of population pressure has been observed on several systems,groundwater resource is one among them.Mismanagement and over-exploitation has not only caused the decline of groundwater levels but also causes deterioration in water quality. Fluoride is one of such parameters where impact of over exploitation has been observed.Fluoride is
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 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,
基金Projects(52090084, 51938008) supported by the National Natural Science Foundation of ChinaProject(2021T140474)supported by the China Postdoctoral Science Foundation。
文摘This paper presents an analytical procedure for massive water-sealing barriers(MWSBs)that are made of partially overlapped jet-grouting columns used for deep excavations,in which two crucial factors of the permeability and strength of jet-grouted materials are considered.Subsequently,a calculation example is analyzed and discussed.Results show that“tension failure”mechanism is a major concern for the structural failure during a design of MWSBs.The maximum allowable seepage discharge is a crucial index for the design of MWSBs,which has a significant influence on determining the design parameters of MWSBs.Compared with the design procedure for MWSBs that is proposed in this paper,the design parameters of MWSBs determined by the stability equilibrium and seepage stability equilibrium approaches are conservative due to the fact that it fails to consider the permeability or strength of jet-grouted materials that makes a contribution to the structural safety.Based on the proposed design method,the ranges of both the thickness and depth of MWSBs for a case history of subway excavation in Fuzhou,China were determined.Finally,field pumping test results showed that the water-tightness performance of MWSBs performed at site was quite well.
文摘The development and growing population has resulted in the increasing demand for potable water in tiny atolls of Lakshadweep group,off the western coast of India.In recent years,the groundwater quality,in such atolls,has been deteriorated due to indiscriminate exploitation of groundwater to meet the demand.Thus arranging a sustainable supply of groundwater has become the most challenging task on these tiny atolls for the survival of human life. Groundwater floats in the form of thin lens,which
文摘The Turonian aquifer of the Tadla’s basin shows at present a pronounced reduction of its hydraulic potential linked to overexploitation and deficiency of effective rains.In order to make an evaluation of the resources of water and implant the exploitation’s drillings of groundwater,a geophysical study by
基金Project(ZDRW-ZS-2021-3)supported by the Key Deployment Projects of Chinese Academy of SciencesProjects(52179116,51991392)supported by the National Natural Science Foundation of China。
文摘In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face.This study employed the finite element method(FEM)to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer.Subsequently,a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure,incorporating various influencing factors.The analysis yields the following conclusions:1)The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable;2)The limit support pressure increases approximately linearly with the pressure head,shield tunnel diameter,and tunnel burial depth.And inversely proportional to the thickness of the impermeable layer,soil cohesion and internal friction angle;3)Through an engineering case study analysis,the results align well with those obtained from traditional theoretical methods,thereby validating the rationality of the equations proposed in this paper.Furthermore,the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness.It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling,thus better reflecting engineering reality.
文摘The seismoelectrical method(also called the Electroseismic method or seismo-electric) is based on the generation of electromagnetic fields in soils and rocks by seismic waves.Although the method is not reported to detect groundwater flow,it does measure the hydraulic conductivity,which is related to permeability and,therefore,to the potential of groundwater flow.Electroseismic technology is an effective tool for the siting of water wells。
