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1.
设计加工扇形渗流槽模型,开展定流量单孔完整井抽水试验,结合自然电位(SP)实时动态监测,研究了潜水含水层抽水过程中水位变化及SP响应特征。结果表明：抽水时,潜水位和SP均快速下降并逐渐稳定,但潜水位降低至稳定时间较短,SP降低至稳定所需时间较长,具有滞后性。抽水流量越大,潜水位和SP降低幅度越大;距离抽水井壁越远,SP稳定所需时间越长。自然电位差ΔSP与水位降深sw之间满足线性函数关系,ΔSP和径向距离r之间满足指数函数关系,根据拟合公式计算得到模型中不同位置处水位降深值,与观测水位降深比较发现两者之间误差较小,表明利用该式可以对抽水过程中潜水位进行计算预测。 相似文献
2.
为了更加准确地确定含水层参数,提出了利用地下水流数值模拟软件Modflow耦合大型抽水试验和长观孔水位两个模型的方法,对含水层参数进行了识别与校验。该方法求得的含水层参数避免了只利用抽水试验模型校验所带来的不确定性,同时利用抽水实验数据进行抽水与恢复的全过程曲线拟合,水位降深模拟相对误差小于6%,提高了含水层参数的准确性。 相似文献
3.
地下水资源评价与地下水可开采量计算,需要对地下含水层组参数进行分析确定。本文结合鲁北地区两个地下水水源地采用抽水试验确定承压含水层水文地质参数的实践,探讨定流量(单孔或多孔)抽水试验确定含水层参数的可行性,并对定降深抽水试验确定水文地质参数方法进行了探索。 相似文献
4.
为求取含水层水文地质参数,常用的试验方法是抽水试验。在进行抽水试验时,经常有越流现象,计算时一般采用越流模型计算。越流模型假定非抽水含水层的水位恒定不变,但在实际抽水过程中,抽水含水层和非抽水含水层间通过越流相互影响、相互作用。如果只考虑抽水含水层的水位变化而不考虑非抽水含水层的水位变化,会导致计算的水文地质参数不准确。实际工作中,有时会在非抽水含水层中布置一口观测井来观测抽水含水层抽水时对非抽水含水层的影响。如果采用多层含水层系统模型的方法,即可利用各含水层观测井中的数据计算出每个含水层和相关弱透水层的水文地质参数,提高参数计算精度、节省资金和工作量。 相似文献
5.
含水层参数对于定性分析区域地下水资源评价、数值模拟及预报、开发利用与保护及科学管理具有重要意义,而江汉平原水文地质参数求解的研究却相对较少.2015年江汉平原1:50 000水文地质调查项目完成杨林尾图幅与陆溪口图幅,选择杨林尾图幅和陆溪口图幅中的4个代表性钻孔,分别做了3组抽水试验和一组压水试验.对抽水数据使用Dupuit公式法结合抽水稳定阶段数据求解含水层参数,同时利用Aquifer Test软件中Theis标准曲线法、直线图解法对抽水试验中非稳定条件下抽水数据对含水层参数求解,得到孔隙水含水层渗透系数及弹性给水度;利用压水试验工程规范求解基岩裂隙含水层的渗透系数.探讨了利用非稳定抽水试验条件下求解含水层参数方法的可行性及该方法的优势.计算结果表明:杨林尾镇浅层(20.2~64.55 m)含水层渗透系数为0.075 m/d,弹性给水度为5.8×10-2;深层(138~160 m)含水层渗透系数为9.89 m/d,弹性给水度为2.3×10-5;陆溪口镇浅层(19.4~36.4 m)含水层渗透系数1.26 m/d,弹性给水度为1.1×10-1;基岩渗透系数为0.012 m/d.通过结果对比分析发现对于单孔非稳定抽水试验,对前期水位降深数据筛选分析,同样可以利用非稳定井流理论反演含水层参数,结果比较可靠. 相似文献
6.
确定含水层参数的全程曲线拟合法 总被引：9，自引：3，他引：6
含水层参数的确定是地下水资源评价、数值模拟、开发利用与保护以及科学管理的重要基础,抽水试验法是确定含水层参数的主要方法。根据含水层抽水试验的泰斯（Theis）公式,运用优化理论,结合计算机技术,提出利用抽水试验数据确定含水层参数的全程曲线拟合法。该方法充分考虑抽水过程中水位快速下降段、水位缓慢下降段和水位恢复段的观测资料,满足计算水位与实测水位之间的误差平方和最小、计算的水位过程线与抽水过程的实测曲线最佳拟合。实例研究表明,该方法速度快、精度高、求参结果最优,既适用于承压含水层求参,又可推广到潜水含水层求参。 相似文献
7.
根据流体运动的能量变化计算单井稳定流抽水涌水量 总被引：1，自引：0，他引：1
赵文玉 《水文地质工程地质》1991,18(1):58-58
在抽水过程中,如果已知某一降深地下水通过井壁周围岩层的孔隙和裂隙流入井内的速度V、过水断面W,可以求出这一降深的涌水量Q=WV。就如图1所示承压井而言,此承压井含水层厚度为M,井半径为v,水位降深为S,抽水前的稳定水位距含水层底板的距离为H_1,抽水后井内的水位距含水层的底板的距离为H_2,设含水断面的有效孔隙率为n_e(即多孔介质 相似文献
8.
抽水试验是获取地下水含水层水文地质参数的有效手段之一。为了准确掌握各含水层特征及水力联系,以巴拉素井田为例,通过抽水试验、理论分析、水质化验等方法对井田先期开采地段内开采煤层富水情况、各主要含水层水文地质特征及其水力联系等进行研究。结果表明:矿井未来开采的2、3、8号煤的富水性均较弱;主要含水层中,除第四系含水层富水性中～强、白垩系洛河组含水层富水性中等以外,其它含水层均富水性弱;第四系含水层和白垩系洛河组含水层之间水力联系密切,侏罗系直罗组含水层与白垩系洛河组含水层之间未发现水力联系,侏罗系直罗组含水层与2号煤之间未发现水力联系;3号煤与8号煤之间未发现水力联系。本次抽水试验成果,为矿井未来水文地质及防治矿井水害工作提供了有力的理论依据,同时对周边条件类似矿井具有一定的借鉴价值。 相似文献
9.
煤矿疏降水工程需要以含水层组参数为基础进行合理布设。结合某矿区内的非稳定流双孔干扰抽水试验,在无观测孔情况下,根据抽水井资料分别利用通用直线法、水位恢复法、解析法及优化拟合四种方法确定承压含水层的导水系数,并利用后期疏降水孔资料对上述方法进行验证,结果表明通用直线法和水位恢复法计算结果可靠。 相似文献
10.
汤邦义 《水文地质工程地质》1984,(3)
本文研究了适用于变流量抽水情况的无越流无限含水层的非稳定流公式,供实际工作中应用。因水平所限,不当之处请指正。一、流向变流量抽水完整井的非稳定流水井公式(一)承压水的非稳定流水井公式假设:(1)含水层各向同性、等厚、产状及原始水位水平;(2)无垂向越流补给,含水层具瞬时释放;(3)地下水为平面二维流,抽水量 Q(t)随时间变 相似文献
11.
Field observation and numerical simulations were carried out to evaluate the hydraulic relationship between the shallow and deep aquifer of a High Plains Aquifer system, in which shallow and deep aquifers are separated by an aquitard. Pumping from the lower aquifer resulted in a small drawdown in the upper aquifer and a larger drawdown in the aquitard; pumping from the shallow aquifer caused a small drawdown in the aquitard and the deep aquifer. Analysis of pumping test data gives the values of the hydraulic conductivity of the aquitard and the deep aquifer. Long-term observation of groundwater levels in the shallow and deep aquifers showed that a strong downward hydraulic gradient was maintained during an irrigation season. Numerical simulations were used to calculate the induced leakage of water from the shallow to the deep aquifer. Water budget analyses suggested that after pumping continues for a couple of days, the leakage from the overlying layers begins to supply the majority of the withdrawal from the deep aquifer. However, the induced leakage from the upper shallow aquifer can travel only a few meters into the aquitard, and it can not reach the lower aquifer during a 90 day pumping period. The major portion of the induced leakage occurred during the pumping period, but a small leakage can continue as a residual effect after the pumping period. The vertical hydraulic conductivity of the aquitard plays a major role in partitioning the ratio of the induced leakage for the pumping and after-pumping periods. 相似文献
12.
Investigation into subsidence hazards due to groundwater pumping from Aquifer II in Changzhou,China 总被引：2，自引：1，他引：1
Ye-Shuang Xu Yao Yuan Shui-Long Shen Zhen-Yu Yin Huai-Na Wu Lei Ma 《Natural Hazards》2015,78(1):281-296
This paper presents an investigation into increased deformation of Aquifer II caused by groundwater pumping from the aquifer in Changzhou, China. As groundwater levels of aquifers have been decreasing in recent decades due to uncontrolled water pumping, land subsidence is becoming a serious geohazard in Changzhou. Based on recently reported field data, the compression of aquitards has not increased compared to that of aquifers with the same scale of layer thickness. The Cosserat continuum model was adopted to analyse the observed phenomenon in this study. A classic Cauchy continuum model is also used for comparison. The comparison between these two models indicates that the proposed approach can interpret the increased deformation well, and the classic Cauchy continuum model underestimates the aquifer deformation as it does not consider shear displacement and macro-rotation. A discussion on the relationship between the groundwater level in the aquifer and subsidence is then undertaken. The results show that the severity of the annual subsidence is correlated with the variation in groundwater level in Aquifer II. To mitigate the subsidence hazards, countermeasures should be adopted to avoid the shear stress in aquifers which results from the high hydraulic gradient, by the appropriate allocation of pumping wells and by restricting groundwater withdrawal volume from each pumping operation. 相似文献
13.
Theis模型、Dupuit模型等经典井流模型分析非均质含水层井流试验数据有一定的局限性,获取的参数不适合表征非均质含水层特性。而GRF模型可以获取含水层流动特性的数据。相比于Theis模型、Dupuit模型,GRF模型更能表征非均质含水层特性。以黄石东湖新村棋盘洲长江大桥的抽水试验数据为例,采用Theis模型和GRF模型计算含水层渗透系数,结合实际水文地质条件,对比分析不同方法计算的水文地质参数,并计算含水层水流维数和表观压力传导系数（Kf /Ssf）。结果表明:研究区含水层为细砂夹条带状黏土透镜体的非均质含水层,采用GRF模型计算结果更符合实际情况,渗透系数为 4.09×10?3cm/s;含水层水流维数为1.61,地下水为双线性流动状态,含水层对抽水试验的响应主要受黏土条带控制;观测井和抽水主井的Kf /Ssf呈非线性相关,进一步验证了含水层的非均质性。在非均质孔隙含水层中,应用多孔联合非稳定GRF井流试验方法不仅能确定水文地质参数,并且能丰富对含水层特性的认知。 相似文献
14.
李超峰 《吉林大学学报(地球科学版)》2021,51(6):1801-1810
为了定量研究与评价含水层之间地下水水力联系程度,首次提出了水力联系系数C（hydraulic connection coefficient）的概念。将水力联系系数C定义为观测孔目的含水层水位降深与该观测孔位置抽水含水层水位降深的比值。通过水力联系系数,可定量评价某含水层水平上同层之间和垂向上不同含水层之间的水力联系程度。依据鄂尔多斯盆地白垩系洛河组各含水层段的水力联系系数C值,将含水层之间水力联系分为5个等级。其中,0.000 0 ≤ C<0.062 5,0.062 5 ≤ C<0.125 0,0.125 0 ≤ C<0.250 0,0.250 0 ≤ C<0.500 0,C ≥ 0.500 0,分别代表水力联系等级为极弱、弱、中等、强、极强。以高家堡井田钻孔抽（放）水试验数据为例,采用水力联系系数和观测孔水位响应时间两个指标定量评价了区内巨厚层状非均质洛河组含水层内部水力联系。结果表明：洛河组中上段水平同层之间的水力联系系数分别为0.373 0、0.413 8,观测孔水位响应时间较短（约为5 min）,水力联系强;洛河组下段水平同层之间水力联系系数分别为0.440 1、0.491 1,观测孔水位响应时间较短（为9~20 min）,水力联系强;洛河组中上段与下段垂向水力联系系数分别为0.000 2、0.007 2、0.089 7,观测孔水位响应时间较长（大于60 min）,水力联系极弱至弱。 相似文献
15.
Environmental tracers are used to estimate groundwater ages and travel times, but the strongly heterogeneous nature of many subsurface environments can cause mixing between waters of highly disparate ages, adding additional complexity to the age-estimation process. Mixing may be exacerbated by the presence of wells because long open intervals or long screens with openings at multiple depths can transport water and solutes rapidly over a large vertical distance. The effect of intraborehole flow on groundwater age was examined numerically using direct age transport simulation coupled with the Multi-Node Well Package of MODFLOW. Ages in a homogeneous, anisotropic aquifer reached a predevelopment steady state possessing strong depth dependence. A nonpumping multi-node well was then introduced in one of three locations within the system. In all three cases, vertical transport along the well resulted in substantial changes in age distributions within the system. After a pumping well was added near the nonpumping multi-node well, ages were further perturbed by a flow reversal in the nonpumping multi-node well. Results indicated that intraborehole flow can substantially alter groundwater ages, but the effects are highly dependent on local or regional flow conditions and may change with time. 相似文献
16.
Analysis of Steady-State Flow To Multiscreened Wells Under Natural Vertical Flow Conditions 总被引：2，自引：0，他引：2
Water levels measured at multiscreened wells in unconfined aquifers may not coincide, in general, with the elevation of the
water table. The presence of vertical gradients (as often is the case in recharge areas) or the existence of confining layers
may cause the water levels to differ from local hydraulic heads in the aquifer. In these cases, a misinterpretation of water
levels may lead to the erroneous conclusion that observed drawdowns are provoked by overpumping. In this paper, we analyze
the effect that a natural vertical gradient has on water levels in wells screened over their entire saturated thickness. As
one would expect, it is observed that, even without pumping, the water level in the wells lies below the water table. Type
curves relating the steady-state drawdown to the vertical gradient and to the hydraulic conductivity anisotropy are presented.
These curves were obtained using a groundwater flow numerical model (FREESURF: Neuman and Witherspoon, 1970). The theoretical
results are checked with field data from deep wells in the detrital Madrid aquifer. In this particular aquifer, it is observed
that the effect of vertical gradients is important both in terms of drawdowns and flow rates.
相似文献
17.
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
18.
为进一步查明孟加拉国巴拉普库利亚煤矿水文地质特征及含水层间水力联系,为矿井水害防治提供理论依据,以19组水质化验数据为基础,结合含水层及隔水层空间展布特征、井田构造特征、水位历时曲线、水化学类型、氢氧同位素特征等,综合分析新近系UDT含水层、Ⅵ煤顶板含水层、Ⅵ煤含水层之间的水力联系。结果表明,井田北部LDT隔水层局部缺失,为UDT含水层水向含煤地层补给提供了条件;井田北翼煤层顶板含水层与UDT含水层水位变化规律密切相关,且水位相近,初步证明两者存在水力联系;各含水层水均为HCO3-Ca·Na·Mg型,均为低矿化度水,进一步证明各含水层间存在水力循环;聚类分析结果表明各含水层水质存在一定关联度,推演含水层间水力联系程度;氢(δD)氧(δ18O)同位素特征点分布于全球大气降水线附近,表明大气降水是各含水层共同的补给水源。研究成果可以指导孟加拉国巴拉普库利亚煤矿Ⅵ煤层开采时水害防治方向。 相似文献
19.
Zhou Xun Chen Mingyou Wan Li Department of Water Resources Environmental Engineering China University of Geosciences Beijing China Wang Juping Ning Xuesheng Beihai Institute of Hydrogeology Engineering Geology Mineral Resour 《中国地质大学学报(英文版)》2000,11(3)
INTRODUCTIONThe city of Beihai,located on the south coast ofGuangxi,China,relies heavily on groundwater for its potablewater supply and agricultural irrigation.With rapid increasein population (for instance,from 134 0 0 0 in 1987to 47930 0in1995 ) and in developm ent program s,the demand for freshwater has been growing. Approxim ately 170 0 0 0 m3/ d ofgroundwater has been pumped from the productive coastalaquifers in recent years.Contamination of the fresh water inthe coastal aquifers b… 相似文献
20.
指出承压含水层盖层的弯曲变形与开采井周围的径向地下水运动存在相互作用, 而这一效应在传统的井流理论中没有被认识到.通过引入弹性薄板理论, 建立了无越流的承压含水层井流-顶板弯曲效应的解析模型, 同时考虑了含水层和水的压缩性, 结果表明Theis井流方程给出的抽水降深偏小.在此基础上推导了有越流承压含水层井流-盖层弯曲效应的偏微分方程, 求出了解析解, 并与传统理论的结果进行了对比, 表明Hantush-Jacob公式计算的降深也是偏小的.在抽水井附近和抽水初期, 传统理论可能导致显著的相对误差. 相似文献