共查询到20条相似文献，搜索用时 84 毫秒
1.
密云水库三维水质模拟技术 总被引：5，自引：0，他引：5
通过水平层面间线性插值计算,模拟密云水库污染质的三维分布.给出水质模拟的3种技术方案:通过着色创建污染质浓度分布的连续图谱,自由设定浓度区间按级差着色的级差分布图谱,创建污染质浓度分布的地图式彩色数字文本浓度分布表.提供基于Windows平台上的数据共享支持. 相似文献
2.
利用高密度电阻率法监测地下介质污染问题的数值模拟 总被引：4，自引：0，他引：4
对地下介质不同污染模式的电性分布特征,给出了不同的地电模型。针对不同的地电模型,利用2.5维有限元正演模拟的方法计算出了不同监测装置形式下的异常分布特征,并给出了针对不同污染模式的最优监测装置形式和异常分析方法。同时模拟分析了对于不同污染程度监测的可行性。 相似文献
3.
本文应用地下水的污染质单离子浓度实际资料，介绍灰色理论GM（1，1）模型在地下水水质变化预报中的可能性，并给出两种参数白化微分方程的求解方法，克服了逆矩阵计算上的困难。 相似文献
4.
总磷运移二维模型的有限元法 总被引：7，自引：4，他引：7
水库中总磷的浓度是水库富营养化的重要指标，根据水库水环境条件，给出污染质总磷运移的二维数学模型；采用Galerlom有限元法进行求解，并给制了等值线图，得到水库中总磷的时空变化规律，为防治水库污染、选择最佳处理方案提供科学理论依据。 相似文献
5.
以大量的地下水测试数据为基础,从污染源分布及水文地质条件入手,对黄河下游平原地下水中有机污染物类型及污染程度进行了深入研究。黄河下游平原地下水普遍受到有机物污染并形成多个典型有机污染区,有机物总检出率为35．5％,检出的有机污染物种类达29种,单个样品检出的有机物种类最多达19种,部分有机物含量超过地下水饮用标准,致使地下水质量恶化。地下水污染区的分布及污染程度与污染源的种类和分布具有很好的相关性。 相似文献
6.
7.
本文提出了一种新的优化地下水监测网络。确定污染羽范围的方法。将监测并安装后最化的污染物存在的不确定性期望值降低到最大的位置定为监测井的最佳位置。本项研究中，将水力传导系数作为诱发不定性的因素。使用连续的随机添加（SRA）法生成水力传导系数的随机场。随着监测网络范围的增大，污染羽分布的不确定性降低。根据这个降低的量．评价某一污染羽存在的信息判定的期望值。选择采集监测井最大信息帚的最小系统为优选的监测网络。为了最化污染羽分布的不确定性。在定义域范围内．针对所有的产生的污染羽的实现值。编制污染物存在的概率图。不确定性定义为。污染物存在的概率或者不存在的概率单元的总和。在非均质水力传导系数场．本文给出了确定最佳监测网络的数值试验的结果。 相似文献
8.
本文针对长江三角洲某地区3个城市(C市、W市、S市)浅层地下水的单环芳烃进行了研究。根据研究区水样分析数据,总结出该地区单环芳烃的污染特点和分布特征,然后从研究区污染源分布、单环芳烃的挥发性、研究区降水以及包气带的防护性能等角度探讨了浅层地下水单环芳烃污染形成的原因。研究表明,该区浅层地下水单环芳烃污染呈点状分布,污染范围不大;浅层地下水单环芳烃污染相对较轻而地表水污染严重。浅层地下水单环芳烃污染特征与研究区工业企业分布、单环芳烃的挥发特性、降水以及研究区包气带防污性能密切相关。浅层地下水单环芳烃污染和工业企业分布具有很好的一致性,有机污染物高浓度的检出点均分布在污染工厂附近,无明显污染源的地段,其浅层地下水水样无有机污染物检出;各检测单环芳烃组分的亨利常数均大于1.01×102Pa·m3·mol-1,所以挥发作用是其主要迁移机理,苯的柱试验表明,苯溶液浓度从1079.0μg/L降低至6.9μg/L仅需26天;研究区包气带为河湖三角洲沉积相的淤泥质粘土,粘粒含量大,粘土矿物含量也很高,富含有机质,其含量大都在1.0%以上,此类土壤具有高的吸附能力,阻滞了污染物向浅层地下水迁移;降雨时浅层地下水中单环芳烃检出率和检出浓度都较高。4种因素综合,使得研究区浅层地下水单环芳烃呈现污染程度轻、分布零散、污染分布范围小的特点。 相似文献
9.
为查明场地污染分布特征,需对场地土壤和地下水进行钻探取样,按规范的检测指标进行逐一测试。在初查和详查阶段将获得大量的土壤和地下水污染数据,数据样本数量大、监测指标多,数据结构复杂,如何从场地大数据中提取价值信息已成为研究热点。以某有机污染场地为例,基于自组织映射神经网络（SOM）和K均值算法开展大数据分析,深入探讨地下水和土壤中各污染指标间的相关性。结果表明:（1）基于自组织映射神经网络的大数据分析可快速挖掘复杂多维的污染场地监测数据,有效完成关键信息的提取;（2）地下水中污染检出指标存在显著的聚类特征,同一聚类中的污染指标具备相似的空间分布特征。对场地污染物检测采取先分类后分级的优化筛选策略,减少污染物检测指标数目,从而有效降低场地检测费用;（3）土壤和地下水中污染检出指标存在良好的空间相关性,这与该污染场地地下水渗流速度缓慢有关。土壤和地下水污染检出指标空间分布的相关性,有助于场地污染源的追溯。 相似文献
10.
随着全球工业化迅猛发展,土壤和地下水六价铬污染日益严重。基于某铁合金厂铬渣场地现场调查与采样分析,开展铬渣场地土样吸附、渗透和弥散试验,研究六价铬在粉质黏土土样中的吸附特性和迁移规律,建立考虑对流-弥散-吸附的六价铬迁移三维动力学模型,结合数值软件获取污染源位于场地上、下游时地下水中六价铬迁移分布特征,并揭示弥散度?和分配系数 对六价铬时空分布的影响。试验结果表明,粉质黏土对六价铬吸附符合Langmuir等温吸附模型,最大吸附量为466.6 mg/kg;蒸馏水和160 mg/L 六价铬溶液入渗下粉质黏土渗透系数约为6.5×10–7～6.7×10–7 cm/s,1 000 mg/L六价铬溶液的渗透系数增大至4.4×10–6 cm/s;粉质黏土水动力弥散系数D为1.4×10–4 m2/d,计算得到阻滞因子 为4.2～10。数值模拟结果表明,场地下游受到六价铬污染时,即使不考虑分子扩散作用,上游仍有被污染的风险,污染程度取决于含水层的弥散度;考虑含水层对六价铬吸附时,土体分配系数越大,六价铬污染羽分布范围越小,在预测地下水中六价铬浓度分布时应重点考虑六价铬吸附等转化过程。 相似文献
11.
以29口钻孔的重矿物百分含量数据来分析样本,通过Q型聚类分析、因子分析方法恢复不同物源体系的发育范围及其母岩类型,并以不同物源体系的边界范围为限定条件,结合ZTR指数及其等值线图,对珠江口盆地惠州凹陷M层物源特征进行了系统的研究。研究结果表明：研究区发育3大物源沉积区,分别为东北-北部物源沉积区、西北物源沉积区和东南物源沉积区,且各区重矿物组合特征明显,主次物源分明,整体表现为母岩类型复杂的特征。东北-北部沉积物主要母岩为酸性岩浆岩,次要母岩为变质岩和沉积岩,西北沉积物主要母岩为中性及基性岩浆岩,次要母岩为酸性岩浆岩和变质岩,东南沉积物主要母岩为中性及基性岩浆岩,次要母岩为变质岩。东北-北部物源区和西北物源区为远源沉积的产物,而东南物源区为近源沉积的产物。东北-北部物源区沉积物来自北方和东北方向,而西北物源区和东南物源区沉积物分别来自西北方向和东南方向。 相似文献
12.
两种煤质分析指标的关联方程组研究 总被引：5，自引：0，他引：5
在综合分析大量文献资料的基础上，采用多元线性回归方法，利用MATLAB对大量煤质分析结果进行了回归分析，推导出了煤质元素分析与工业分析的关联方程组。新方法实现了由工业分析结果求元素分析成分的目的，具有重大的实用意义。 相似文献
13.
An algorithm andFortran-iv computer program,cabfac, forQ-mode factor analysis is described. The program will accept up to 1500 items and 50 variables on a moderate-size computer. 相似文献
14.
Ibsen Chivatá Cárdenas 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2019,13(1):53-65
In this paper, we report on the use of Bayesian networks, BNs, learnt from data generated by physical and numerical models, to overcome to a certain degree a number of complications in traditional slope stability analyses that jointly consider the mechanical and hydraulic properties of soils. Discrete Bayesian networks resulted to be useful and efficient to acquire knowledge from simulated data and to identify significant factors by the combined use of backward inference and global sensitivity analysis. Further, BNs enable decision thresholds to be estimated quickly. Along with this, backward inference and global sensitivity analysis are performed in BNs at low computation costs. Moreover, under conditions in which knowledge is scarce, we show how a practitioner can be better informed using the proposed approach. All these previously under-reported modelling features in the specialised literature encourage the further application of the proposed approach to enhance slope stability analysis. 相似文献
15.
A piston core from the southern Blake Basin penetrated nine distinct bioclastic carbonate turbidites separated by pelagic terrigenous clay units. X-ray diffraction analysis of the carbonate mineralogy of the graded, laminated, and homogenous units of the individual turbidite units indicated a general loss of unstable carbonates in the homogenous unit beyond that contained in the lower two units. Univariate and multivariate statistical tests were employed to determine the significance of the changes and to determine if different units of a turbidite sequence could be consistently grouped by statistical methods. Principal components, discriminant function, and cluster analysis were used in the multivariate tests. The graded and laminated units were closely related in mineralogy with little significant differences. The mineralogy of the homogenous units was significantly different than that of the other two units except in one example. Cluster analysis generated five groupings of the samples with the end members consisting of graded and laminated units at one end and homogenous units at the other. 相似文献
16.
以有限元结构矩阵分析为理论基础，结合应力应变测试和现场实际使用情况，利用计算机结构分析程序，对ＺＴ－Ａ系列三个不同高度钻塔的天梁、塔腿和绷绳做了结构应力分析，弄清了Ａ形塔在承受垂直荷载、水平荷载以及偏载条件下，组成钻塔的各构件的荷载及应力分布；对钻塔设计提出了改进意见；并从整体角度分析了绷绳的作用；对在不同荷载条件下有无绷绳时钻塔的结构应力从量上做了对比；最后提出了应当如何布置提升系统才会使钻塔处 相似文献
17.
Ulf Grenander 《Mathematical Geology》1975,7(3):267-278
A deformation mechanism is described and analyzed. It is intended for height patterns exposed to erosion and tectonic activity.
A simulation experiment is carried out for this model. Closedform expressions are derived for the covariance field, the properties
of spectral estimates, and for the optimal retrospective reconstruction of earlier, unknown height patterns. For obvious reasons
the author is in no position to make claims about the verisimilitude of the model. It is offered as an example of a potential
application to geology of the theory of patterns developed by the author and his coworkers in recent years. It is hoped that
those more qualified than the author in the subject matter area can extend and modify the analysis to make it closer to geological
reality.
supported by NSF grant GJ-3100X. 相似文献
18.
Paul F. Czeglédy 《Mathematical Geology》1972,4(4):291-305
On the basis of samples taken from a known topographic surface, the parameters of two types of linear models are estimated. The first category is defined by polynomials or trigonometric functions, whose parameters are simultaneously computed from available data. In the second category a set of local centers is defined, and in the neighborhood of each center a fixed-degree polynomial is developed. An approximative resemblance index is calculated, and contour maps corresponding to various models are compared with the topographic map. It is found that with an increasing number of grid points, maps of local polynomials are converging both in continuity and in resemblance. For a sufficient number of grid points, this resemblance is always higher than those produced by models of the first category. 相似文献
19.
Finite element limit analysis with plane strain condition is employed to determine the upper and lower bound solutions of the undrained limiting pressure behind soil gaps and the lateral force acting on a pile per unit length in a contiguous pile wall. Computed bound solutions confirm serious limitations of existing studies in predicting these two solutions. Predicted failure mechanisms and the arching effect behind soil gaps are discussed. A closed-form equation of the limiting pressure factor is proposed for a convenient and accurate prediction of the lateral force acting on a pile in contiguous pile walls in practice. 相似文献
20.
Keith J. Tinkler 《Mathematical Geology》1971,3(4):335-355
A quantitative analysis was made of the spatial arrangement of 149explosion craters in the western rift of Uganda. A variety of methods demonstrate that the spatial pattern of the craters reveals significant structural patterns that have guided volcanism to the surface. It is shown that the east-west elements in the field affected location, and the main rift fault is resolved into two main components. Tentatively, a possible dextral transform fault is identified that affected the relative location of the two main zones of activity. Grouping techniques demonstrate that crater groups obey an exponential rank-size rule and allow a mapping of the craters into energy classes that reveals a concentric pattern of energy in the field. The effect of the topography on energy levels and crater size show that only topography greater than 11,000ft could have prevented all eruptive activity, but the smaller energies and craters are sensitive to height differences on the order of the height of the rift wall, about 1000ft. Total energy in each crater class size is roughly constant, and the field energy could create one or two single craters comparable in size to small central volcanoes. 相似文献