淮南市朱集东矿井新生界松散层地下水开采保证程度评价     

王海波  李磊 《中国煤炭地质》2011,(9):42-44,51

利用淮南市朱集东矿井新生界松散层供水水文地质勘探成果和抽水试验资料,查明了区内新生界松散层供水含水层的供水水文地质条件,认为第一含水层埋藏浅,易受污染,水量随季节变化大,不宜作为生活饮用水供水水源,第三含水层水质较差,亦不作为生活饮用水供水水源,确定了第二含水层为矿区主要供水层位。采用解析法对第二含水层的水量进行了计算,并设计了布井方案,计算了井群水量;水位预报结果表明,开采50a后,3#、4#井中的水位最大降深为35.229m,小于其顶板埋深,说明拟建井群布置是合适的。评价结果为矿井供水设计提供了依据。  相似文献   

浅议测井曲线在松树头煤矿含水层解释中的应用     

马永祥  海晶 《中国煤炭地质》2011,(11):57-59

以松树头煤矿水文地质勘查为例,介绍了测井曲线在含水层解释中的应用。实例表明,自然伽马、自然电位和视电阻率三种曲线对含水层具有明显的异常反应,在含水层中,前二种曲线表现为负异常,后者表现为正异常;对于隔水层,前二种曲线则表现为正异常,而视电阻率表现为负异常。根据测井解释成果与钻孔消耗量、岩心及抽水试验资料相互印证,解释松树头煤矿ZK5-2钻孔368.30～406.42m段,从上到下依次为含水层、隔水层、含水层、隔水层四段。另外,从实例应用的三种曲线可知,视电阻率曲线对于岩石粒度及含水层具有明显的响应特征,极差高达117Ω.m。  相似文献   

The hydraulic conductivity field and groundwater flow in the unconfined aquifer system of the Keta Strip,Ghana     

《Journal of African Earth Sciences》2013

This study investigates the hydraulic conductivity field and the groundwater flow pattern as predicted by a calibrated steady state groundwater flow model for the Keta Strip, southeastern Ghana. The hydraulic conductivity field is an important parameter in evaluating aquifer properties in space, and in general basin-wide groundwater resources evaluation and management. This study finds that the general hydraulic conductivity of the unconsolidated unconfined aquifer system of the Keta Strip ranges between 2 m/d and 20 m/d, with an average of 15 m/d. The spatial variation in horizontal hydraulic conductivity appears to take the trend in the variations in the nature of the material in space. Calibrated groundwater recharge suggests that 6.9–34% of annual precipitation recharges the shallow aquifer system. This amount of recharge is significant and suggests high fortunes in terms of groundwater resources development for agriculture and industrial activities in the area. A spatial distribution of groundwater recharge from precipitation is presented in this study. The spatial pattern appears to take the form of the distribution in horizontal hydraulic conductivity, and suggests that the vertical hydraulic conductivity takes the same pattern of spatial variation as the horizontal hydraulic conductivity. This is consistent with observations in other areas. The resulting groundwater flow is dominated by local flow systems as the unconfined system is quite shallow. A general northeast – southwest flow pattern has been observed in the study area.  相似文献   

Numerical modeling of groundwater inflow from a confined aquifer into Sangan open pit mine,northeast Iran     

《Geomechanics and Geoengineering》2013,8(3):189-199

Numerical models are useful in the evaluation of the interaction between groundwater systems and mining activities. They can be successfully used to predict the quantity of inflow into open pits and to design an appropriate dewatering system. In this paper, a two-dimensional axi-symmetric finite element model called SEEP/W has been used to predict the groundwater inflow into Sangan open pit mine (anomaly north C). The Sangan iron mine is located at 280 km south-east of Mashhad, Iran, in arid and warm climate conditions wherein precipitation is generally limited. The water inflow to the pit is mainly from a confined aquifer, mainly by horizontal flow in the upper layers and vertical flow at the pit bottom. The results of the numerical model of the ground water inflow are presented and compared with those obtained from Theis, Cooper-Jacob and Jacob-Lohman analytical solutions. Ground water inflow monitoring was also carried out in a trial excavation at the Sangan mine in order to calibrate the model. The model was then used to predict groundwater inflow into Sangan open pit mine during its advancement. This model provides valuable information for designing an appropriate dewatering system.  相似文献   

Genesis of an endoreic piezometric coastal depression in sub-Sahelian Western Africa: the Continental Terminal Aquifer of Trarza (Mauritania)     

《Geodinamica Acta》2013,26(5):389-400

Despite its capital importance, the genesis of endoreic water table depressions in Western sub-Sahelian Africa is not well known yet. It is the case of the Trarza Aquifer, which is the main resource of drinkable water for Nouakchott. While water needs are growing steadily, global warming is threatening this resource. The genesis of piezometric depression is the object of this study, which analyses it in the light of the hydrochemistry of the western border of the Trarza aquifer, which is located in proximity of the Atlantic Ocean and its salt wedge.

The hydrochemical facies of groundwater in the Idini pumping site, 60 km East of Nouakchott, and that of a Nouakchott to the Senegal River transect, should be categorised into 3 groups: 1) chloro-sulfated 2) sulfato-chlorinated and chloro-bicarbonated. Such facies, which are also sodocalcic, indicate that mineralization is of mixed origin (marine and continental).

After reviewing the main mathematical models for piezometric depression, the present study attempts a conceptualization of the piezometric evolution of this phreatic aquifer (Continental Terminal) during the Quaternary. It highlights the dominant role of evaporation in the evolution of the water table of the Trarza aquifer, whose impact is similar to the one of the Quaternary marine level increase.  相似文献   

昆明市地热田越流含水系统中地下热水的数值模拟   总被引：7，自引：0，他引：7  

薛传东  刘星  杨浩  李保珠  谈树成 《地球科学进展》2003,18(6):899-905

深层基岩地下（热）水水化学污染问题日趋严重,急需定量而仿真地模拟和预报天然状态和各种人为工程经济活动下地下（热）水流动及溶质（或污染物）的运移。在充分认识地质、水文地质条件的基础上,建立了考虑温压变化和越流条件的昆明市地热田深层基岩地下热水系统中水流和溶质运移的准三维非稳定流数学模型。模型用于开采条件下地热田地下热水水位及 F^－、Cl^－浓度的模拟,模拟结果具有较高的仿真性,拟合误差一般小于 2％～5％,表明模型合理、可靠。应用所建模型预测了开采条件下昆明市地热田II块段地下热水流场和溶质浓度动态的变化趋势,并提出了控制地下热水环境进一步恶化的措施。  相似文献   

Optimal design of pumping tests in leaky aquifers for stream depletion analysis     

Steen Christensen  Vitaly A. Zlotnik  Daniel M. Tartakovsky 《Journal of Hydrology》2009,375(3-4):554-565

We analyze the optimal design of a pumping test for estimating hydrogeologic parameters that are subsequently used to predict stream depletion caused by groundwater pumping in a leaky aquifer. A global optimization method is used to identify the test’s optimal duration and the number and locations of observation wells. The objective is to minimize predictive uncertainty (variance) of the estimated stream depletion, which depends on the sensitivities of depletion and drawdown to relevant hydrogeologic parameters. The sensitivities are computed analytically from the solutions of Zlotnik and Tartakovsky [Zlotnik, V.A., Tartakovsky, D.M., 2008. Stream depletion by groundwater pumping in leaky aquifers. ASCE Journal of Hydrologic Engineering 13, 43–50] and the results are presented in a dimensionless form, facilitating their use for planning of pumping test at a variety of sites with similar hydrogeological settings. We show that stream depletion is generally very sensitive to aquitard’s leakage coefficient and stream-bed’s conductance. The optimal number of observation wells is two, their optimal locations are one close to the stream and the other close to the pumping well. We also provide guidelines on the test’s optimal duration and demonstrate that under certain conditions estimation of aquitard’s leakage coefficient and stream-bed’s conductance requires unrealistic test duration and/or signal-to-noise ratio.  相似文献   

Contribution of magnetic resonance sounding to aquifer characterization and recharge estimate in semiarid Niger   总被引：4，自引：0，他引：4  

J.M. Vouillamoz  G. Favreau  S. Massuel  M. Boucher  Y. Nazoumou  A. Legchenko 《Journal of Applied Geophysics》2008,64(3-4):99-108

To improve the knowledge of the regionally important Continental Terminal 3 (CT3) aquifer in south-western Niger, fifteen magnetic resonance soundings (MRS) were carried out in December 2005 in the vicinity of wells and boreholes. The output MRS geophysical parameters, i.e. water content and decay constants versus depth, were compared to hydrogeological characteristics, i.e. water table depth, total porosity, specific yield and transmissivity estimated from direct measurements, pumping tests and transient groundwater modelling. The MRS-determined parameters were then used to estimate the rates of groundwater recharge.Contained in poorly consolidated Tertiary sandstones, the CT3 aquifer's water table has continuously risen by 4 m in total over the past four decades. Additionally, a significant portion of this increase has occurred in the past decade alone, with an annual rise now ranging between 0.1 and 0.3 m depending on the monitored well. Increase in groundwater recharge due to land clearance and deforestation explains this situation. According to previous estimations, the pre-clearing recharge ranged from 1 to 5 mm per year in 1950–60 s, while more recent recharge rates (1990s–2000s) range from 20 to 50 mm per year. These recharge values are directly affected by estimated aquifer specific yield value, while the spatial variation of rates of water table rise can be attributed to large scale hydrodynamic heterogeneities in the aquifer. However, few field measurements were available to confirm these assumptions.The main results of this study are: (1) The water table depth and aquifer transmissivity are estimated from MRS output parameters with an average accuracy of ± 10% and ± 9% respectively. (2) The MRS-determined water content is linked to both the total porosity and the specific yield of the aquifer, but no quantitative formulation can be proposed as yet. (3) Using the average MRS-determined water content over the investigated area, i.e. 13%, the groundwater recharge rates can be estimated to be ~ 2 mm per year in the 1950–1960s (pre-clearing period), and ~ 23 mm per year for the last decade. (4) The variations in specific yield and transmissivity cannot explain by themselves the spatial variability of the rise of the water table. (5) The ranges in transmissivity and water content obtained from MRS are more realistic than the groundwater modelling outputs. Therefore, MRS could be used to better constrain the aquifer parameters in groundwater modelling with a dense site network.Finally, this work illustrates how MRS can successfully improve characterisation and transient multi-year groundwater balance of commonly found sedimentary aquifers, particularly when integrated with well observations and pumping tests.  相似文献   

用水位恢复数据反演越流承压含水层参数   总被引：1，自引：0，他引：1  

杨建民  郑刚 《岩土力学》2008,29(6):1602-1606

水文地质勘测中,由于水位恢复阶段没有人力和机械因素干扰,由测量数据可以画出平滑的曲线,更适宜于分析水文地质参数,但经典非稳定流Theis公式和Theis水位恢复法所依据的若干假设条件在实际中难以满足。针对越流承压含水层具有补给条件而很快稳定以及非稳定抽水阶段流量常“抖动”的特点,论证了利用稳定流量和Hantush-Jacob越流模型计算的可行性,并用扩展的卡尔曼滤波器反演水文地质参数,经文献中历史数据和实地抽水试验检验结果表明,由该方法反演的预测值和实测值吻合良好。  相似文献   

探地雷达测量近地表含水量的研究   总被引：1，自引：0，他引：1  

董航  刘四新  王春晖  曾昭发  鹿琪  王者江  易兵 《吉林大学学报(地球科学版)》2009,39(1):163

为充分验证探地雷达方法用于测量近地表含水量的有效性和可靠程度,基于探地雷达的反射波法,根据介电常数、电磁波传播速度和含水量三者之间的关系,着重分析了探地雷达反射波法用于测量含水量的相关理论和特点,设计了适用于高频雷达信号的速度分析算法,建立了用于分析该问题的局部含水层模型。利用FDTD方法模拟分析了不同测量方式下,局部含水层的探地雷达响应,借助速度分析理论及Topp公式,反演得到了研究区域的含水量。  相似文献