This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ent...This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.展开更多
Based on observed data from Tanggu District in Tianjin, a back-propagation neural network (BPNN) model was introduced to predict possible land subsidence due to exploitation of groundwater. According to model estimati...Based on observed data from Tanggu District in Tianjin, a back-propagation neural network (BPNN) model was introduced to predict possible land subsidence due to exploitation of groundwater. According to model estimation under various hypothetical extraction scenarios, patterns of land subsidence at Tanggu District were studied and discussed.The predicted average background land subsidence rate of Tanggu is 9.47 mm/a.The significance of contribution of aquifers to land subsidence descends in order of units Ⅳ,Ⅲ,Ⅴ,Ⅱ.Land subsidence tends to deteriorate with the increase in total extraction rate.展开更多
Nowadays, the researches of using Differential Interferometric Synthetic Aperture Radar (D-InSAR) tech- nique to monitor the land subsidence are mainly on how to qualitatively analyze the subsidence areas and values, ...Nowadays, the researches of using Differential Interferometric Synthetic Aperture Radar (D-InSAR) tech- nique to monitor the land subsidence are mainly on how to qualitatively analyze the subsidence areas and values, but the analysis of subsidence process and mechanism are insufficient. In order to resolve these problems, 6 scenes of ERS1/2 images captured during 1995 and 2000 in a certain place of Jiangsu province were selected to obtain the subsidence and velocities in three time segments by ''two-pass'' D- InSAR method. Then the relationships among distributions of pumping wells, exploitation quantity of groundwater, and confined water levels were studied and the subsidence mechanism was systematically analyzed. The results show that using D-InSAR technique to monitor the deformation of large area can obtain high accuracies, the disadvantages of classical observation methods can be remedied and there is a linear relationship among the velocities of land subsidence, the water level and the exploitation quantity.展开更多
There is a potential to certain extend for groundwater development in the piedmont plain in south edge of Tarim Basin. If the surface water use keeps the scale as present, the maximum safe yield of groundwater is abou...There is a potential to certain extend for groundwater development in the piedmont plain in south edge of Tarim Basin. If the surface water use keeps the scale as present, the maximum safe yield of groundwater is about 2.05 × 109m3/a that is 55.8% of the recharge. Thus the evapotranspiration discharge will reduce 60.4%, while spring water reducing 35.6%. If the surface water use rate is up to 80% and coefficient of canal water use increase to 0.55 in the future, the maximum safe yield of groundwater will reduce to 1.85 × 109m3/a with the recharge reducing to 3.1 × 109m3. However, the sustainable groundwater development is depended on the protection of the quality aspect linked with the quantity aspect. In particular, protection of the glaoier and water conservation forestry in the Kunlun Mountains and coordinating development of surface water and groundwater should be taken seriously. Besides, the legislation, administrative management and the technology construction, and ability construction are also critical important and necessary.展开更多
Based on five basic assumptions, of the ground subsidence and collapse was using theoretical analysis method, the nature revealed from the mechanics point. Divided into four phases as groundwater level descent, soil c...Based on five basic assumptions, of the ground subsidence and collapse was using theoretical analysis method, the nature revealed from the mechanics point. Divided into four phases as groundwater level descent, soil cavity formation, soil cavity expansion, and ground collapse emersion, the whole process of ground subsidence and collapse was analyzed in detail. The study shows that ground subsidence and collapse is the macro- scopic performance and inevitable result of the soil cavity expansion and development, and the dynamic mechanics is the spalling force induced by the groundwater falling. The activities of underground water play a very important role in the process from the formation of soil cavity to the production of ground subsidence.展开更多
Phreatic water resources are widely found in thick unconsolidated surface layers in western China, where water levels respond sensitively and quickly to large-scale underground mining in conjunction with shallow coal ...Phreatic water resources are widely found in thick unconsolidated surface layers in western China, where water levels respond sensitively and quickly to large-scale underground mining in conjunction with shallow coal seams. Longwall face #32201 of the Bulianta Coal Mine, in the Shendong coalfield was selected as an industrial trail base, where field observations on ground-water levels were conducted when the working face was below a water-rich area. The space-time variation in the behavior of un-consolidated water levels in response to underground mining and its relation with of advance were observed through the field trials. The basic conditions for water preservation in mines are presented and the mechanisms of water preservation in mining analyzed, given the geological condition of two key strata and a severely weathered layer buried in the overburden. The field trails show that water preservation in mining shallow coal seams can be successful under suitable conditions, providing new technology for envi-ronmental protection in the desert coalfields of northwestern China.展开更多
It is very important for secure mining under water bodies to study the effects of Iongwall mining on the underground water. In order to study this problem, piezometers for monitoring underground water levels were esta...It is very important for secure mining under water bodies to study the effects of Iongwall mining on the underground water. In order to study this problem, piezometers for monitoring underground water levels were established in an American coalmine. Large amounts of pre-mining and post-mining monitoring data were collected. Based on the data the effects of Iongwall mining on the underground water was studied. The results demonstrate that when the piezometer monitoring wells have an interburden thickness less than 72.7 m, the groundwater level decreases immediately to immeasurable levels and go dry after undermining. The height of the fractured zone in is 72.7-85.3 m in this geological and mining conditions. The results also show that the calculated value of fractured zone by the empirical formulae used in China is smaller than the actual results. Therefore, it is not always safe to use them in analysis of mining under water bodies.展开更多
As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mini...As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.展开更多
Al Jabal al Akhdar(Green Mountain) in arid northern Oman has freshwater resources that had supported small communities for hundreds of years. Jabal Akhdar receives more rainfall(300-400 mm) when compared to the desert...Al Jabal al Akhdar(Green Mountain) in arid northern Oman has freshwater resources that had supported small communities for hundreds of years. Jabal Akhdar receives more rainfall(300-400 mm) when compared to the desert plains. In the last few years, this region had undergone enormous changes due to rapid development. The resident and transient populations have increased and their activities exert severe stress on the water resources. There are 24 retention reservoirs in the area, but most are eutrophic and the nutrient loading is due to input of animal fecal matter via surface run-off. As expected, these waters contaminated with coliform bacteria and some have pathogenic Escherichia coli. Drinking water needs of all the villages met by groundwater extraction. Because of poor quality, the surface water in the reservoirs is under-utilized. A low-cost lowmaintenance treatment system designed, constructed and operated in one village to clean the reservoir water for non-drinking human use. The treatment unit improved the water quality parameters. A survey among the adult male population of the village showed their eagerness to adopt this system and use the treated reservoir water for uses other than agriculture. Establishment of these treatment units in other villages should reduce the pressures on groundwater extraction.展开更多
Florida's artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a un...Florida's artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a unique freshwater ecology dependent on perennial flows, constant temperature and chemistry, and high light transmissivity. Numerous observations indicate that Florida's springs flows are declining as a result of the increasing extraction of groundwater for human uses. North Florida's karst environment is especially susceptible to nitrogen pollution from agricultural and urban development. An empirical springs/aquifer water budget is needed to better understand these spring stressors. Discharge data from 393 of the state's 1,000+ artesian springs are used to estimate trends in total spring discharge by decade since 1930-39. This analysis indicates that average spring flows have declined by about 32%. Large groundwater pumping centers are altering spring flows over the whole springs region. Existing groundwater pumping rates from the Floridan Aquifer in 2010 were more than 30% of average annual aquifer recharge, and allocated groundwater use in north-central Florida is nearly double current estimated uses. Based on biological research conducted in Florida springs, these flow reductions are from two to six times greater than declines known to result in significant harm to aquatic resources.展开更多
The Gondo plain lies between Mali and Burkina Faso and it is in interland basin into the West African Craton. Since 2003, this study has been carried out two research projects on the southwest part of the plain, where...The Gondo plain lies between Mali and Burkina Faso and it is in interland basin into the West African Craton. Since 2003, this study has been carried out two research projects on the southwest part of the plain, where the piezometric levels are very low (50 m to 100 m). It has two main purposes: find water resources to provide drinking water supply to Ouahigouya town and assess the exploitation possibility of the deep aquifer for rural water supply. Combined methods were used to reach the objectives of this study--remote sensing, geology, geophysics (electromagnetism and resistivity methods), hydrochemistry and isotope chemistry. So, the methodology allows to specify the geology and the tectonic of the eastern border of the basin, identify and characterize the different aquifers and their relationships. Through the implementation of 250 m deep drilled boreholes, this study reveals that the water level of the lower Cambrian limestones can be under pressure below the continental terminal deposits. The study highlights paleo-karstic zones in the Gondo plain and shows that water chemistry and isotope chemistry can be used to differentiate water sheets and evaluate their recharge.展开更多
The purpose of this paper is to clarify how the Kabu-ido system can be employed to successfully regulate groundwater pumping. This was accomplished by analyzing surviving historical documents, including budgetary note...The purpose of this paper is to clarify how the Kabu-ido system can be employed to successfully regulate groundwater pumping. This was accomplished by analyzing surviving historical documents, including budgetary notes and a diary. The Kabu-ido system was a customary institution for groundwater management in a ring levee area of the Noubi Plain in Japan that consisted of three programs: restriction of groundwater pumping through a permit system, groundwater pricing and economic compensation. The system was created in the 1810s and survived for 100 years. This paper covers the Kabu-ido system from the 1810s to the 1860s, the first half of the 100-year history. Excessive groundwater pumping is not a new environmental problem. Although many case studies have investigated remedial actions, few have investigated how local residents addressed the problem before the 20th century because of a lack of documents. The Kabu-ido system is an exception in which of the procedure was documented in writing. The historical data indicate that it was a pioneering institution for groundwater management.展开更多
This article presents the results of dividing the hydrogeological structure zones in aquifer of Cai Phan Rang river basin, Ninh Thuan province, Viet Nam, and the relationship between parameters of hydrogeological stru...This article presents the results of dividing the hydrogeological structure zones in aquifer of Cai Phan Rang river basin, Ninh Thuan province, Viet Nam, and the relationship between parameters of hydrogeological structure zones with water storage capacity of hydrogeological structure. Research results divided hydrogeological structure of Cai Phan Rang River Basin into four zones, including three zones with depression bedrock and one zone with slope bedrock, and the results assessed: (1) specific discharge of exploitation well is proportional to zone area of hydrogeological structure; (2) specific discharge of exploitation well is inversely proportional to slope of bedrock surface, slope of water level in zone and area of drainage surface of hydrogeological structure zone; (3) water level fluctuation in zone is proportional to slope of bedrock surface, slope of water level in zone and inversely proportional to distribution area of zone; (4) total mineralization of water is proportional to bedrock surface slope and water level slope in zone, and inversely proportional to drainage surface area of zone and volume of structural depression. Research results are practical significance in solutions proposal to increase exploitation capacity for various water use purposes.展开更多
The most useful indicators should be established, designed and customized based on local issues of a target area. In order to establish groundwater sustainability indicators for the Vietnam capital, Hanoi, in this stu...The most useful indicators should be established, designed and customized based on local issues of a target area. In order to establish groundwater sustainability indicators for the Vietnam capital, Hanoi, in this study, the sustainability assessment framework of groundwater resources from an economic perspective is proposed for the first time with the focus of Hanoi current groundwater problems. An AHP (Analytical Hierarchy Process) approach is employed to generate the main components (aspects and indicators) of this framework, because development of composite indicators is considered to be a best approach for sustainability evaluation. To do this, the current problems of Hanoi groundwater resources were carefully reviewed and explored to propose three main aspects (quantity, quality and management) and appropriately construct their 9 MESIs (Macroeconomic Sustainability Indicators). As for the results, the sustainability indices of the quantity, quality and management aspects were appropriately assessed as good, excellent and good sustainability levels, respectively. As a result, the sustainability of Hanoi groundwater resources development is economically good, indicating that there has been a big effort to improve the groundwater sustainability from both sides, the local government and communities.展开更多
The projection for groundwater states that the total domestic water demand for greater Bangalore would increase from 1,170 MLD in 2010 to 1,336 MLD in 2016. Dependence on groundwater is ever increasing due to rapid In...The projection for groundwater states that the total domestic water demand for greater Bangalore would increase from 1,170 MLD in 2010 to 1,336 MLD in 2016. Dependence on groundwater is ever increasing due to rapid Industrialization & Urbanization. It is estimated that almost 40% of the population of Bangalore is dependent on groundwater. Due to the unscientific disposal of domestic and industrial waste generated, groundwater is getting highly polluted in the city. The scale of this impact will depend mainly upon the water-service infrastructure, the superficial geology and the regional setting. The quality of ground water is equally important as that of quantity. Jointed and fractured granites and gneisses constitute the major aquifer system of BBMP (Bruhat Bengaluru Mahanagara Palike) area. Two new observatory borewells were drilled and lithology report has been prepared. Petrographic Analysis (XRD/XRF) and Water Quality Analysis were carried out as per the standard methods. Petrographic samples were analysed by collecting chip of rock from the borewell for every 20 ft depth, most of the samples were similar and samples were identified as Biotite-Gneiss, Schistose Amphibolite. Water quality analysis was carried out for individual chemical parameters for two borewells drilled. The 1st Borewell struck water at 150 ft (total depth-200 ft) & 2nd struck at 740 ft (total depth-960 ft). Five water samples were collected till end of depth in each borewell. Chemical parameter values such as, Total hardness (360-348, 280-320) mg/ltr, Nitrate (12.24-13.5, 45-48) mg/ltr, Chloride (104-90, 70-70) mg/ltr, Fe (0.75-0.09, 1.288-0.312) mg/ltr etc. are calculated respectively. Water samples were analysed from various parts of BBMP covering 750 sq kms, also thematic maps (IDW method) of water quality are generated for these samples for post-monsoon season. The study aims to explore the sub-surface lithological layers and the thickness of weathered zone, which indirectly helps to know the groundwater pollution source near surface water bodies, dug wells, etc. The above data are interpreted for future ground water resources planning and management.展开更多
In order to study the effect of Iongwall mining on surface stream water, monitoring stations of water flow rate was established. A lot of water flowing data were collected before, during and after Iongwall mining. Bas...In order to study the effect of Iongwall mining on surface stream water, monitoring stations of water flow rate was established. A lot of water flowing data were collected before, during and after Iongwall mining. Based on monitoring data, the effects of Iongwall mining on surface stream water were analyzed. The results demonstrate that Iongwall mining has effects on the surface stream water; and the stream water would be lost and decrease due to Iongwall mining but never go into underground through fractured zone. Also, the mechanism of water loss due to Iongwall mining was presented. The stream water can go into the surface cracks in the intersection of stream and surface cracks, longwall mining subsidence can change the surface stream slope and the downstream water flowing status. The results also show the effects of Iongwall mining on stream water are temporary and about one or two years later, surface stream water can be recovered.展开更多
The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of ...The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×10^8m^3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×10^8m^3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons: firstly, water transfer project will bring to the Basin 60x108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows: keeping strengthening water demand management, raising water price as well as subsidies for the low- income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.展开更多
The judicious use and management of natural resources is vital to achieve sustainable development.Land and water are prime natural resources,and their depletion and degradation can lead to serious threats like land su...The judicious use and management of natural resources is vital to achieve sustainable development.Land and water are prime natural resources,and their depletion and degradation can lead to serious threats like land subsidence.Land subsidence is a phenomenon of the alteration of elevation at a point on the earth through the sinking of the surface.It occurs when the earth’s surface loses its support.The major causes of land subsidence include groundwater extraction,mining,construction overload,and other similar factors that increase pressure on the surface and eventually subsidize the land.Urban centers with excessive groundwater extraction and infrastructure development are at a high risk of subsidence.Lahore,the second-largest city in Pakistan,is undergoing an enormous increase in population density,uncontrolled urbanization with very large-scale construction projects,and intensive groundwater extraction which are responsible for subsidence directly or indirectly.Therefore,studies on groundwater status and unplanned urban appraisals have seriously urged monitoring of the subsidence in Lahore.Herein,we used freely available Sentinel-1 data for one year(from August 2018 to August 2019),with a high spatial and temporal resolution,to monitor subsidence in Lahore.The data were processed using the SNAP/Sta MPS approach for Persistent Scatterer Interferometric Synthetic Aperture Radar(PSI)analysis,which is an advanced InSAR technique.The displacement velocity map from InSAR processing shows a significant land deformation in the area with values ranging from-114 to 15 mm yr^(-1).Along with the Sentinel-1 data,we also used supplementary data obtained from various government agencies of Pakistan to study the land cover map,transportation network and waterways of Lahore,soil types,population density,and field points for assessing the results and understanding the roles of various factors in the occurrence of uplift or subsidence.A strong correlation was established between subsidence and various parameters such as groundwater extraction and lowering of the water table,soil type variations,land cover changes,surface water channels,and population density.The deformation map confirms the greatest subsidence in the central part of Lahore,while the uplift is observed in the less populated and rural areas situated near Ravi River.The land subsidence and uplift could be attributed to groundwater extraction and recharge through the canal system and the river,respectively.展开更多
基金supported by the National Nature Science Foundation of China (U1234206 and 61503311)+4 种基金support under the Railways Technology Development Plan of China Railway Corporation (2016X008-J)the Fundamental Research Funds for the Central Universities (2682015CX039)supported by the National United Engineering Laboratory of Integrated and Intelligent Transportation
文摘This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.
基金Supported by Tianjin Land Subsidence Controlling Office(No.kJ/095).
文摘Based on observed data from Tanggu District in Tianjin, a back-propagation neural network (BPNN) model was introduced to predict possible land subsidence due to exploitation of groundwater. According to model estimation under various hypothetical extraction scenarios, patterns of land subsidence at Tanggu District were studied and discussed.The predicted average background land subsidence rate of Tanggu is 9.47 mm/a.The significance of contribution of aquifers to land subsidence descends in order of units Ⅳ,Ⅲ,Ⅴ,Ⅱ.Land subsidence tends to deteriorate with the increase in total extraction rate.
基金provided by the National Natural Science Foundation of China (No.41071273)the Fundamental Research Funds for the Central Universities (No. 2010QNA21)the Project Sponsored by the Scientific Research Foundation of Key Laboratory for Land Environmentand Disaster Monitoring of SBSM (No. LEDM2011B07)
文摘Nowadays, the researches of using Differential Interferometric Synthetic Aperture Radar (D-InSAR) tech- nique to monitor the land subsidence are mainly on how to qualitatively analyze the subsidence areas and values, but the analysis of subsidence process and mechanism are insufficient. In order to resolve these problems, 6 scenes of ERS1/2 images captured during 1995 and 2000 in a certain place of Jiangsu province were selected to obtain the subsidence and velocities in three time segments by ''two-pass'' D- InSAR method. Then the relationships among distributions of pumping wells, exploitation quantity of groundwater, and confined water levels were studied and the subsidence mechanism was systematically analyzed. The results show that using D-InSAR technique to monitor the deformation of large area can obtain high accuracies, the disadvantages of classical observation methods can be remedied and there is a linear relationship among the velocities of land subsidence, the water level and the exploitation quantity.
基金the auspices of the National Natural Science Foundation of China(No. 49731010).
文摘There is a potential to certain extend for groundwater development in the piedmont plain in south edge of Tarim Basin. If the surface water use keeps the scale as present, the maximum safe yield of groundwater is about 2.05 × 109m3/a that is 55.8% of the recharge. Thus the evapotranspiration discharge will reduce 60.4%, while spring water reducing 35.6%. If the surface water use rate is up to 80% and coefficient of canal water use increase to 0.55 in the future, the maximum safe yield of groundwater will reduce to 1.85 × 109m3/a with the recharge reducing to 3.1 × 109m3. However, the sustainable groundwater development is depended on the protection of the quality aspect linked with the quantity aspect. In particular, protection of the glaoier and water conservation forestry in the Kunlun Mountains and coordinating development of surface water and groundwater should be taken seriously. Besides, the legislation, administrative management and the technology construction, and ability construction are also critical important and necessary.
基金Supported by the National Natural Science Foundation of China(10702072)the Technology Innovation Fundation of China Coal Research Institute(2009CX01)
文摘Based on five basic assumptions, of the ground subsidence and collapse was using theoretical analysis method, the nature revealed from the mechanics point. Divided into four phases as groundwater level descent, soil cavity formation, soil cavity expansion, and ground collapse emersion, the whole process of ground subsidence and collapse was analyzed in detail. The study shows that ground subsidence and collapse is the macro- scopic performance and inevitable result of the soil cavity expansion and development, and the dynamic mechanics is the spalling force induced by the groundwater falling. The activities of underground water play a very important role in the process from the formation of soil cavity to the production of ground subsidence.
基金supports for this work provided by the Research Fund of the State Key Laboratory of Coal Resources and Mine Safety (NoSKLCRSM08X2)the Jiangsu "333" High Qualified Talents, the National Natural Science Foundation of China (No50904063)the Scientific Research Foundation of China University of Mining & Technology (Nos.2008A003 and 2009A001)
文摘Phreatic water resources are widely found in thick unconsolidated surface layers in western China, where water levels respond sensitively and quickly to large-scale underground mining in conjunction with shallow coal seams. Longwall face #32201 of the Bulianta Coal Mine, in the Shendong coalfield was selected as an industrial trail base, where field observations on ground-water levels were conducted when the working face was below a water-rich area. The space-time variation in the behavior of un-consolidated water levels in response to underground mining and its relation with of advance were observed through the field trials. The basic conditions for water preservation in mines are presented and the mechanisms of water preservation in mining analyzed, given the geological condition of two key strata and a severely weathered layer buried in the overburden. The field trails show that water preservation in mining shallow coal seams can be successful under suitable conditions, providing new technology for envi-ronmental protection in the desert coalfields of northwestern China.
文摘It is very important for secure mining under water bodies to study the effects of Iongwall mining on the underground water. In order to study this problem, piezometers for monitoring underground water levels were established in an American coalmine. Large amounts of pre-mining and post-mining monitoring data were collected. Based on the data the effects of Iongwall mining on the underground water was studied. The results demonstrate that when the piezometer monitoring wells have an interburden thickness less than 72.7 m, the groundwater level decreases immediately to immeasurable levels and go dry after undermining. The height of the fractured zone in is 72.7-85.3 m in this geological and mining conditions. The results also show that the calculated value of fractured zone by the empirical formulae used in China is smaller than the actual results. Therefore, it is not always safe to use them in analysis of mining under water bodies.
基金sponsored by the National Natural Science Foundation of China (No.50974053)Pennsylvania Service Corporation at Waynesburg,USA
文摘As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.
文摘Al Jabal al Akhdar(Green Mountain) in arid northern Oman has freshwater resources that had supported small communities for hundreds of years. Jabal Akhdar receives more rainfall(300-400 mm) when compared to the desert plains. In the last few years, this region had undergone enormous changes due to rapid development. The resident and transient populations have increased and their activities exert severe stress on the water resources. There are 24 retention reservoirs in the area, but most are eutrophic and the nutrient loading is due to input of animal fecal matter via surface run-off. As expected, these waters contaminated with coliform bacteria and some have pathogenic Escherichia coli. Drinking water needs of all the villages met by groundwater extraction. Because of poor quality, the surface water in the reservoirs is under-utilized. A low-cost lowmaintenance treatment system designed, constructed and operated in one village to clean the reservoir water for non-drinking human use. The treatment unit improved the water quality parameters. A survey among the adult male population of the village showed their eagerness to adopt this system and use the treated reservoir water for uses other than agriculture. Establishment of these treatment units in other villages should reduce the pressures on groundwater extraction.
文摘Florida's artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a unique freshwater ecology dependent on perennial flows, constant temperature and chemistry, and high light transmissivity. Numerous observations indicate that Florida's springs flows are declining as a result of the increasing extraction of groundwater for human uses. North Florida's karst environment is especially susceptible to nitrogen pollution from agricultural and urban development. An empirical springs/aquifer water budget is needed to better understand these spring stressors. Discharge data from 393 of the state's 1,000+ artesian springs are used to estimate trends in total spring discharge by decade since 1930-39. This analysis indicates that average spring flows have declined by about 32%. Large groundwater pumping centers are altering spring flows over the whole springs region. Existing groundwater pumping rates from the Floridan Aquifer in 2010 were more than 30% of average annual aquifer recharge, and allocated groundwater use in north-central Florida is nearly double current estimated uses. Based on biological research conducted in Florida springs, these flow reductions are from two to six times greater than declines known to result in significant harm to aquatic resources.
文摘The Gondo plain lies between Mali and Burkina Faso and it is in interland basin into the West African Craton. Since 2003, this study has been carried out two research projects on the southwest part of the plain, where the piezometric levels are very low (50 m to 100 m). It has two main purposes: find water resources to provide drinking water supply to Ouahigouya town and assess the exploitation possibility of the deep aquifer for rural water supply. Combined methods were used to reach the objectives of this study--remote sensing, geology, geophysics (electromagnetism and resistivity methods), hydrochemistry and isotope chemistry. So, the methodology allows to specify the geology and the tectonic of the eastern border of the basin, identify and characterize the different aquifers and their relationships. Through the implementation of 250 m deep drilled boreholes, this study reveals that the water level of the lower Cambrian limestones can be under pressure below the continental terminal deposits. The study highlights paleo-karstic zones in the Gondo plain and shows that water chemistry and isotope chemistry can be used to differentiate water sheets and evaluate their recharge.
文摘The purpose of this paper is to clarify how the Kabu-ido system can be employed to successfully regulate groundwater pumping. This was accomplished by analyzing surviving historical documents, including budgetary notes and a diary. The Kabu-ido system was a customary institution for groundwater management in a ring levee area of the Noubi Plain in Japan that consisted of three programs: restriction of groundwater pumping through a permit system, groundwater pricing and economic compensation. The system was created in the 1810s and survived for 100 years. This paper covers the Kabu-ido system from the 1810s to the 1860s, the first half of the 100-year history. Excessive groundwater pumping is not a new environmental problem. Although many case studies have investigated remedial actions, few have investigated how local residents addressed the problem before the 20th century because of a lack of documents. The Kabu-ido system is an exception in which of the procedure was documented in writing. The historical data indicate that it was a pioneering institution for groundwater management.
文摘This article presents the results of dividing the hydrogeological structure zones in aquifer of Cai Phan Rang river basin, Ninh Thuan province, Viet Nam, and the relationship between parameters of hydrogeological structure zones with water storage capacity of hydrogeological structure. Research results divided hydrogeological structure of Cai Phan Rang River Basin into four zones, including three zones with depression bedrock and one zone with slope bedrock, and the results assessed: (1) specific discharge of exploitation well is proportional to zone area of hydrogeological structure; (2) specific discharge of exploitation well is inversely proportional to slope of bedrock surface, slope of water level in zone and area of drainage surface of hydrogeological structure zone; (3) water level fluctuation in zone is proportional to slope of bedrock surface, slope of water level in zone and inversely proportional to distribution area of zone; (4) total mineralization of water is proportional to bedrock surface slope and water level slope in zone, and inversely proportional to drainage surface area of zone and volume of structural depression. Research results are practical significance in solutions proposal to increase exploitation capacity for various water use purposes.
文摘The most useful indicators should be established, designed and customized based on local issues of a target area. In order to establish groundwater sustainability indicators for the Vietnam capital, Hanoi, in this study, the sustainability assessment framework of groundwater resources from an economic perspective is proposed for the first time with the focus of Hanoi current groundwater problems. An AHP (Analytical Hierarchy Process) approach is employed to generate the main components (aspects and indicators) of this framework, because development of composite indicators is considered to be a best approach for sustainability evaluation. To do this, the current problems of Hanoi groundwater resources were carefully reviewed and explored to propose three main aspects (quantity, quality and management) and appropriately construct their 9 MESIs (Macroeconomic Sustainability Indicators). As for the results, the sustainability indices of the quantity, quality and management aspects were appropriately assessed as good, excellent and good sustainability levels, respectively. As a result, the sustainability of Hanoi groundwater resources development is economically good, indicating that there has been a big effort to improve the groundwater sustainability from both sides, the local government and communities.
文摘The projection for groundwater states that the total domestic water demand for greater Bangalore would increase from 1,170 MLD in 2010 to 1,336 MLD in 2016. Dependence on groundwater is ever increasing due to rapid Industrialization & Urbanization. It is estimated that almost 40% of the population of Bangalore is dependent on groundwater. Due to the unscientific disposal of domestic and industrial waste generated, groundwater is getting highly polluted in the city. The scale of this impact will depend mainly upon the water-service infrastructure, the superficial geology and the regional setting. The quality of ground water is equally important as that of quantity. Jointed and fractured granites and gneisses constitute the major aquifer system of BBMP (Bruhat Bengaluru Mahanagara Palike) area. Two new observatory borewells were drilled and lithology report has been prepared. Petrographic Analysis (XRD/XRF) and Water Quality Analysis were carried out as per the standard methods. Petrographic samples were analysed by collecting chip of rock from the borewell for every 20 ft depth, most of the samples were similar and samples were identified as Biotite-Gneiss, Schistose Amphibolite. Water quality analysis was carried out for individual chemical parameters for two borewells drilled. The 1st Borewell struck water at 150 ft (total depth-200 ft) & 2nd struck at 740 ft (total depth-960 ft). Five water samples were collected till end of depth in each borewell. Chemical parameter values such as, Total hardness (360-348, 280-320) mg/ltr, Nitrate (12.24-13.5, 45-48) mg/ltr, Chloride (104-90, 70-70) mg/ltr, Fe (0.75-0.09, 1.288-0.312) mg/ltr etc. are calculated respectively. Water samples were analysed from various parts of BBMP covering 750 sq kms, also thematic maps (IDW method) of water quality are generated for these samples for post-monsoon season. The study aims to explore the sub-surface lithological layers and the thickness of weathered zone, which indirectly helps to know the groundwater pollution source near surface water bodies, dug wells, etc. The above data are interpreted for future ground water resources planning and management.
基金Supported by Pennsylvania Service Corporation at Waynesburg, Pennsylvania, USA the 0utstanding Youth Science Foundation of Henan Province (0612002100), China.
文摘In order to study the effect of Iongwall mining on surface stream water, monitoring stations of water flow rate was established. A lot of water flowing data were collected before, during and after Iongwall mining. Based on monitoring data, the effects of Iongwall mining on surface stream water were analyzed. The results demonstrate that Iongwall mining has effects on the surface stream water; and the stream water would be lost and decrease due to Iongwall mining but never go into underground through fractured zone. Also, the mechanism of water loss due to Iongwall mining was presented. The stream water can go into the surface cracks in the intersection of stream and surface cracks, longwall mining subsidence can change the surface stream slope and the downstream water flowing status. The results also show the effects of Iongwall mining on stream water are temporary and about one or two years later, surface stream water can be recovered.
基金supported by the National Natural Sciences Fund of China (40971298)
文摘The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×10^8m^3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×10^8m^3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons: firstly, water transfer project will bring to the Basin 60x108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows: keeping strengthening water demand management, raising water price as well as subsidies for the low- income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.
基金The National Natural Science Foundation of China(41930110)。
文摘The judicious use and management of natural resources is vital to achieve sustainable development.Land and water are prime natural resources,and their depletion and degradation can lead to serious threats like land subsidence.Land subsidence is a phenomenon of the alteration of elevation at a point on the earth through the sinking of the surface.It occurs when the earth’s surface loses its support.The major causes of land subsidence include groundwater extraction,mining,construction overload,and other similar factors that increase pressure on the surface and eventually subsidize the land.Urban centers with excessive groundwater extraction and infrastructure development are at a high risk of subsidence.Lahore,the second-largest city in Pakistan,is undergoing an enormous increase in population density,uncontrolled urbanization with very large-scale construction projects,and intensive groundwater extraction which are responsible for subsidence directly or indirectly.Therefore,studies on groundwater status and unplanned urban appraisals have seriously urged monitoring of the subsidence in Lahore.Herein,we used freely available Sentinel-1 data for one year(from August 2018 to August 2019),with a high spatial and temporal resolution,to monitor subsidence in Lahore.The data were processed using the SNAP/Sta MPS approach for Persistent Scatterer Interferometric Synthetic Aperture Radar(PSI)analysis,which is an advanced InSAR technique.The displacement velocity map from InSAR processing shows a significant land deformation in the area with values ranging from-114 to 15 mm yr^(-1).Along with the Sentinel-1 data,we also used supplementary data obtained from various government agencies of Pakistan to study the land cover map,transportation network and waterways of Lahore,soil types,population density,and field points for assessing the results and understanding the roles of various factors in the occurrence of uplift or subsidence.A strong correlation was established between subsidence and various parameters such as groundwater extraction and lowering of the water table,soil type variations,land cover changes,surface water channels,and population density.The deformation map confirms the greatest subsidence in the central part of Lahore,while the uplift is observed in the less populated and rural areas situated near Ravi River.The land subsidence and uplift could be attributed to groundwater extraction and recharge through the canal system and the river,respectively.