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鄂尔多斯盆地周边分布着神东、陕北、黄陇和宁东四个大型煤炭基地,煤炭资源丰富,但开采利用程度低,是我国＂十二五＂期间重点开发的矿区。在系统分析盆地内侏罗系煤层顶板白垩系裂隙含水层和第四系萨拉乌苏组孔隙含水层富水性的基础上,揭示了含水层与煤层的叠置关系;以煤炭开采破坏含水层、煤层与含水层距离、煤层与地表距离、含水层富水性为依据,将含水层破坏模式划分为：破坏顶板萨拉乌苏组含水层亚区、煤层埋藏浅破坏顶板含水层及生态环境亚区、破坏顶板含水层富水性较好亚区、破坏顶板含水层富水性较弱亚区,并对含水层破坏程度进行了分区评价;最后提出了含水层保护措施,为煤炭开采后的防治水工作提供了依据。 相似文献
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“Source du (?)ez”岩溶含水层系统(北蒙皮立(North Montpellieran)岩溶区-Franle S.E.)是内陆类型的岩溶含水层系统演化的地质控制的例子。岩溶含水层系统的演化主要受气候(和古气候)、地质和生物的控制。气候控制水进入岩溶含水层系统后,地质就成了主要的控制因索。地质控制包括: 1.岩性(和古沉积岩相)控制; 2.构造控制; 3.地形雕塑作用和其平面控制; 4.其它地质控制(电磁的,变质的,火山的) 相似文献
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复合含水层系统地下水资源评价三维数值模型 总被引：6，自引：5，他引：1
江苏省盐城市地下含水系统为一复合含水层系统,采用真三维模型,将其概化为三度空间上的非均质各向异性.在对模型进行识别、验证的基础上,结合对地面沉降、咸水入侵等地质环境控制的要求,规划、预测了到2020年12月底,第Ⅱ承压含水层、第Ⅲ承压含水层和第Ⅳ承压含水层中的最低地下水位分别恢复到-20 m、-30 m和-40 m时,各含水层中地下水的开采量及地下水的最优开采布局,并预测了未来各含水层地下水位降落漏斗趋于稳定的地下水开采量. 相似文献
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在分析煤矿开发方案及其地质环境的基础上,从含水层的结构、水位和水质三个方面研究煤矿开采对含水层的破坏,并提出留设防水煤柱、污水处理和含水层监测的含水层防治措施,以保护地下水资源. 相似文献
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山西庞庞塔矿地下水化学特征及含水层间水力联系分析 总被引：1，自引：0，他引：1
依据矿区补勘钻孔抽水取得的水质化验资料,重点对影响煤层开采的奥陶系中统石灰岩岩溶裂隙含水层和太原组灰岩岩溶裂隙含水层进行了水化学特征分析,结果发现,奥陶系峰峰组含水层中SO42-离子含量普遍较高,大部分地段高于HCO3-离子含量,阳离子以Ca2+和Mg2+离子为主,水化学类型以SO4-Ca· Mg型为主;上马家沟组含水层SO42-离子含量较峰峰组岩溶裂隙水明显下降.根据各钻孔水质化验的主要离子成分、矿化度、总硬度及水化学类型进行各含水层间的水力联系分析,认为峰峰组含水层与上马家沟组含水层、太灰含水层与奥灰含水层水力联系均较弱.该研究可为矿井开采中开展水害防治提供参考. 相似文献
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依据岩性岩相研究、孔隙度研究、物探洲井解译等成果,对鄂尔多斯白垩系盆地含水层系统的结构进行了划分与研究.结果袁明:盆地北部沙漠高原区含水层系统为单一结构,表现为强富水与中等富水含水层在垂向上叠置与组合,无区域性连续稳定的隔水层,由下到上构成含水统一体;南部黄土高原区为多层结构,表现为含水层与隔水层上下叠置,垂向水文地质分层明显:盆地南、北含水层的结构类型明显不同.利用孔隙度、渗透系数、单位涌水量3个参数,对含水层的富水性级别进行了划分,盆地中共划分出7个强富水含水层、7个中等富水含水层和2个弱富水舍水层.盆地南、北比较,北部含水层孔隙度大,富水性强,地下水主要富集于盆地北部地区.垂向上比较,盆地北部由上到下,孔隙度由大变小,富水性由强变弱,地下水主要富集于浅层和中层:南部上部罗汉洞组和下部洛河组孔隙度较大,富水性好,中部环河组相对较差.地下水主要富集于罗汉洞组和洛河组. 相似文献
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横河煤矿底含放水孔与井田内供水井连通试验研究 总被引：1，自引：0，他引：1
在邹城市宏河矿业集团横河煤矿井田范围内,有多眼供水井.由于这些供水井大部分穿透了第四系松散层,致使上部含水层和底部含水层串通,造成对矿井水的补给.但较长时期以来,由于缺乏直接的证据,对供水井与煤矿底含涌水之间的关系看法不一,从而造成对矿井水防治决策的困扰.通过化学示踪法跟踪地下水的流向,证实是供水井自身结构串通了第四系含水层上、中、下组,从而造成上组含水层对底部含水层的补给. 相似文献
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用稳定流承压含水层公式对半承压含水层求参数时,计算出的导水系数“T”比非稳定流计算出的要大,影响半径R与经验系数相比普通偏小.用水位恢复法计算也同样.原因在于半承压含水层中地下水受潜水垂向越流补给及水平径向补给,因而用稳定流承压含水层法计算时,或者修改公式,或者用非稳定流计算. 相似文献
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为加强地下水管理,摸清区域含水层分布,介绍了利用现有水井,应用物探方法测量其剖面视电阻率曲线,确定含水层分布的方法。 相似文献
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为实现滨海含水层地下水开采-回灌方案优化、控制海水入侵面积和降低海水入侵损失等多重管理目标,建立了海水入侵条件下地下水多目标模拟优化管理模型SWT-NPTSGA。模拟模型采用基于变密度流的数值模拟程序SEAWAT来模拟海水入侵过程。优化模型采用小生境Pareto禁忌遗传混合算法NPTSGA来求解,该算法在保证多目标权衡解的收敛性和计算效率的前提下,能维护整个进化群体的全局多样性。将SWT-NPTSGA程序应用于一个理想滨海含水层地下水开采方案和人工回灌控制海水入侵的优化设计中,结果表明该管理模型能够同时处理最大化总抽水流量、最小化人工回灌总量和最小化海水入侵范围等3个目标函数之间的权衡关系。通过采用人工回灌海水入侵区的减灾策略,既能增加滨海地区的供水量,又可减少海水入侵的范围,由此进一步验证了模型的有效性和可靠性。 相似文献
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A modeling study of seawater intrusion in Alabama Gulf Coast,USA 总被引：4，自引：0，他引：4
A numerical model of variable-density groundwater flow and miscible salt transport is developed to investigate the extent
of seawater intrusion in the Gulf coast aquifers of Alabama, USA. The SEAWAT code is used to solve the density-dependent groundwater
flow and solute transport governing equations. The numerical model is calibrated against the observed hydraulic heads measured
in 1996 by adjusting the zonation and values of hydraulic conductivity and recharge rate. Using the calibrated model and assuming
all the hydrogeologic conditions remain the same as those in 1996, a predictive 40-year simulation run indicates that further
seawater intrusion into the coastal aquifers can occur in the study area. Moreover, the predicted intrusion may be more significant
in the deeper aquifer than the shallower ones. As the population continues to grow and the demand for groundwater pumping
intensifies beyond the 1996 level, it can be expected that the actual extent of seawater intrusion in the future would be
more severe than the model prediction. Better strategies for groundwater development and management will be necessary to protect
the freshwater aquifers from contamination by seawater intrusion.
相似文献
| Jin LinEmail: |
13.
Seawater intrusion is one of the most serious environmental problems in many coastal regions all over the world. Mixing a small quantity of seawater with groundwater makes it unsuitable for use and can result in abandonment of aquifers. Therefore, seawater intrusion should be prevented or at least controlled to protect groundwater resources. This paper presents development and application of a simulation‐optimization model to control seawater intrusion in coastal aquifers using different management scenarios; abstraction of brackish water, recharge of freshwater, and combination of abstraction and recharge. The model is based on the integration of a genetic algorithm optimisation technique and a coupled transient density‐dependent finite element model. The objectives of the management scenarios include determination of the optimal depth, location and abstraction/recharge rates for the wells to minimize the total costs for construction and operation as well as salt concentrations in the aquifer. The developed model is applied to analyze the control of seawater intrusion in a hypothetical confined coastal aquifer. The efficiencies of the three management scenarios are examined and compared. The results show that combination of abstraction and recharge wells is significantly better than using abstraction wells or recharge wells alone as it gives the least cost and least salt concentration in the aquifer. The results from this study would be useful in designing the system of abstraction/recharge wells to control seawater intrusion in coastal aquifers and can be applied in areas where there is a risk of seawater intrusion. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
14.
Monitoring and methods to analyse the groundwater quality degradation risk in coastal karstic aquifers (Apulia,Southern Italy) 总被引：1，自引：0，他引：1
A multi-methodological approach based on monitoring and spatio-temporal analysis of groundwater quality changes is proposed.
The presented tools are simple, quick and cost-effective to give service to all sorts of users. The chief purpose of the monitoring
network is the detection of the piezometric or potenziometric level in the aquifer. The spatial and multi-temporal analysis
of usual chemical and physical data provides both an assessment of the spatial vulnerability of the aquifer to seawater intrusion,
defining a salinity threshold between fresh groundwater and brackish groundwater and of the water quality trend in terms of
salinity. The evaluation of the salinity trend or of salinity-correlated parameters highlights the effects of groundwater
mismanagement. The multiparameter logging provides a rapid groundwater quality classification for each well. The whole approach
allows evaluating the effects of current management criteria and designing more appropriate management targets. The Apulian
karstic coastal aquifers have been selected as a case study (Southern Italy). Three types of aquifer zones can be distinguished:
(1) areas with low vulnerability to seawater intrusion, (2) areas with high vulnerability and (3) areas with variable vulnerability
in which the salt degradation largely depends on the ability to manage the well discharge. The water quality degradation caused
by seawater intrusion appears to be a combined effect of an anomalous succession of drought periods observed from about 1980
onwards and increased groundwater pumping, particularly during drought periods. A management criterion based on aquifer zones
is proposed. 相似文献
15.
A thirty-year artificial recharge experiment in a coastal aquifer in an arid zone: The Teboulba aquifer system (Tunisian Sahel) 总被引：1，自引：0，他引：1
With the increased demand for groundwater resulting from fast demographic growth, accelerated urbanization, economic and agricultural activity diversification, and the increase of per capita consumption, ground water resources, in particular in coastal regions, remain relatively low, compared to demand. The groundwater quality and piezometric variations result mainly from intensive exploitation, agricultural activities and the intrusion of seawater. This phenomenon is observed mostly in semi-arid areas, such as the oriental Sahel of Tunisia, where an apparent reduction in rainfall in recent years can be seen. Groundwater becomes overexploited especially as its natural recharge by rainwater does not succeed in maintaining the hydrologic balance. The imbalance between water demand and resources induces the degradation of the water quality. In such a case, the artificial recharge of water-table aquifers by water from dams is a credible alternative to improve the hydrodynamic and physicochemical conditions of the groundwater. Like most coastal aquifers, the Teboulba water-table aquifer is threatened by overexploitation for at least three decades. This threat appears by a considerable piezometric level drop and by water salinisation, due to seawater intrusion. Given this alarming situation, since 1971, artificial recharge through wells with surface water from a dam was tested in order to restore the water levels and to improve water quality. The piezometric and chemical surveys of the Teboulba aquifer permitted one to describe the temporal and spatial piezometric and geochemical conditions of the aquifer and to show the effect of the artificial recharge. Indeed, the artificial recharge undertaken since 1971 made the geochemical and piezometric conditions of the Teboulba aquifer improve. This example is a rare, well-documented case-study of the benefits of artificial recharge in a coastal aquifer, over the long term. 相似文献
16.
A review of seawater intrusion and its management in Australia 总被引：5，自引：3，他引：2
Adrian D. Werner 《Hydrogeology Journal》2010,18(1):281-285
Extended periods of below-average rainfall combined with a rising population density in the Australian coastal margin have led to higher stresses on coastal water resources, and the risk of seawater intrusion has increased. Despite reports of seawater intrusion in the majority of states and evidence that some Australian coastal aquifers are seriously depleted, comprehensive seawater intrusion investigations have only been completed for coastal systems in Queensland and to a lesser degree in Western Australia and South Australia. The degree of assessment appears to be linked to the perceived economic value of the groundwater resource. The most detailed studies include those of the Pioneer Valley and Burnett basins in Queensland, for which conceptual and mathematical models have been developed at the regional scale, and have been used to underpin trigger-level management approaches to protect against further seawater intrusion. Historical responses to seawater intrusion include the establishment of artificial recharge schemes; the most prominent being that of the Lower Burdekin aquifers in Queensland. Recommendations for future solutions include enhanced fit-for-purpose seawater intrusion monitoring, continuing research into investigation methods, and improved knowledge-sharing through education programs and the development of national guidelines for seawater intrusion assessment and management. 相似文献
17.
Greece is dependent on groundwater resources for its water supply. The main aquifers are within carbonate rocks (karstic aquifers)
and coarse grained Neogene and Quaternary deposits (porous aquifers). The use of groundwater resources has become particularly
intensive in coastal areas during the last decades with the intense urbanization, tourist development and irrigated land expansion.
Sources of groundwater pollution are the seawater intrusion due to over-exploitation of coastal aquifers, the fertilizers
from agricultural activities and the disposal of untreated wastewater in torrents or in old pumping wells. In the last decades
the total abstractions from coastal aquifers exceed the natural recharge; so the aquifer systems are not used safely. Over-exploitation
causes a negative water balance, triggering seawater intrusion. Seawater intrusion phenomena are recorded in coastal aquifer
systems. Nitrate pollution is the second major source of groundwater degradation in many areas in Greece. The high levels
of nitrate are probably the result of over-fertilization and the lack of sewage systems in some urban areas. 相似文献
18.
Groundwater resource sustainability in the Wadi Watir delta, Gulf of Aqaba, Sinai, Egypt 总被引：3，自引：2，他引：1
Mustafa A. Eissa James M. Thomas Greg Pohll Ronald L. Hershey Kamal A. Dahab Maher I. Dawoud Abdelfattah ElShiekh Mohamed A. Gomaa 《Hydrogeology Journal》2013,21(8):1833-1851
The Wadi Watir delta, in the arid Sinai Peninsula, Egypt, contains an alluvial aquifer underlain by impermeable Precambrian basement rock. The scarcity of rainfall during the last decade, combined with high pumping rates, resulted in degradation of water quality in the main supply wells along the mountain front, which has resulted in reduced groundwater pumping. Additionally, seawater intrusion along the coast has increased salinity in some wells. A three-dimensional (3D) groundwater flow model (MODFLOW) was calibrated using groundwater-level changes and pumping rates from 1982 to 2009; the groundwater recharge rate was estimated to be 1.58?×?106 m3/year. A variable-density flow model (SEAWAT) was used to evaluate seawater intrusion for different pumping rates and well-field locations. Water chemistry and stable isotope data were used to calculate seawater mixing with groundwater along the coast. Geochemical modeling (NETPATH) determined the sources and mixing of different groundwaters from the mountainous recharge areas and within the delta aquifers; results showed that the groundwater salinity is controlled by dissolution of minerals and salts in the aquifers along flow paths and mixing of chemically different waters, including upwelling of saline groundwater and seawater intrusion. Future groundwater pumping must be closely monitored to limit these effects. 相似文献
19.
Evaluation and numerical modeling of seawater intrusion in the Gaza aquifer (Palestine) 总被引：3，自引：1，他引：3
A numerical assessment of seawater intrusion in Gaza, Palestine, has been achieved applying a 3-D variable density groundwater flow model. A two-stage finite difference simulation algorithm was used in steady state and transient models. SEAWAT computer code was used for simulating the spatial and temporal evolution of hydraulic heads and solute concentrations of groundwater. A regular finite difference grid with a 400 m2 cell in the horizontal plane, in addition to a 12-layer model were chosen. The model has been calibrated under steady state and transient conditions. Simulation results indicate that the proposed schemes successfully simulate the intrusion mechanism. Two pumpage schemes were designed to use the calibrated model for prediction of future changes in water levels and solute concentrations in the groundwater for a planning period of 17 years. The results show that seawater intrusion would worsen in the aquifer if the current rates of groundwater pumpage continue. The alternative, to eliminate pumpage in the intruded area, to moderate pumpage rates from water supply wells far from the seashore and to increase the aquifer replenishment by encouraging the implementation of suitable solutions like artificial recharge, may limit significantly seawater intrusion and reduce the current rate of decline of the water levels. 相似文献
20.
To investigate the relative importance of projected sea-level rise, climate change effects on recharge, and groundwater extraction on seawater intrusion in important coastal aquifers in Atlantic Canada, a three-dimensional numerical model of density-dependent groundwater flow coupled with solute transport was developed for the Richibucto region of New Brunswick. The model was used, with an efficient 2k factorial design approach, to perform simulations for the period 2011–2100. The results of the factorial analyses indicate that the relative importance of the three factors investigated varies depending on the model location considered. The effect of declining recharge is most significant at shallow to intermediate depths along the freshwater–seawater transition zone, while the effect of increasing pumping rates dominates at a location relatively close to the well field. The effect of sea-level rise is shown to be significant only at the much deeper inland toe of the transition zone. The spatial variation in importance is related to how different model boundary conditions influence freshwater flow at the different locations within the model domain. This investigation indicates that sea-level rise has the least significant effect (of the three factors considered) on future seawater intrusion in sandstone aquifers in the Richibucto region. 相似文献