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1.
指示克立格法的理论及方法 总被引：5，自引：1，他引：5
地质、物化探数据的分布常出现一个长尾巴,这种分布特征影响了矿产储量计算及数据处理的精度.引起这种非正态分布的因素有:数据中有特异值,它的出现表明矿床具有高品位的矿化作用,这对储量计算及数据处理是很重要的;数据由若干个总体组成,即所谓的混合总体.对这种数据,普通克立格法是不稳健的.为此,本文介绍一种新的地质统计学方法——指示克立格法(非参数方法).文中讨论了(1)指示函数及其二阶矩;(2)指示半变异函数;(3)指示克立格方程组;(4)待估块段品位的指示克立格估计.最后,还介绍1个应用实例,并给出了计算方法和步骤. 相似文献
2.
指示克立格是一种非参数统计方法,它能在不舍弃特异值的条件下进行有效的空间估计,协同克立格以协同区域化变量的研究对象,充分考虑了变量空间相关性和变量间的统计相关性,有着单变量克立格法可可比拟的优点,因而,本文提出协同－指示克立格法这一方法,在指示克立格中考虑多变量的空间相关性和变量间的统计相关性,使指示克拉立格与协同克立格相互补充,模拟现实,提高预测精度,并以胜利油田罗家砂四上砾岩为例进行参数预测, 相似文献
3.
协同克立格法,同时兼具化探数据多元性及克立格法表征空间属性的特点。考虑到地质变量两个以上的空间属性,在化探数据处理中运用协同克立格法,可以进一步提高估计精度。运用协同克立格法对广西林旺矿区中金元素成矿进行预测,经相关性分析显示,在矿区中元素的基本组合是Au、Ag、As、Hg,协同克立格插值以Au为主要变量,伴生元素Ag、As、Hg为次要变量。把插值计算后的结果与传统多元统计方法和普通克立格法的计算结果进行比较,结果协同克立格法得到的估值误差较小,预测精度较高,在成矿元素的预测中具有一定程度的优越性。 相似文献
4.
普朗铜矿床铜品位分布地质统计学研究 总被引：5，自引：0，他引：5
运用地质统计学的方法对普朗矿区铜品位分布情况进行了研究,建立了铜品位变异规律的数学模型,分别得到了矿体厚度、倾向和走向3个方向的变异函数,该函数呈几何异向性,比值为1:1.612:3.869,反映出矿体铜品位在3个方向上的相关性较好,说明铜品位分布总体变化系数不大,有利于矿山的开采.统计得出铜品位属于正态分布,表明下一步用普通克立格法进行估值效果最好,为矿山规划设计和生产提供了理论依据. 相似文献
5.
时空多元协同克立格的理论研究 总被引：11，自引：0，他引：11
本文结合地质统计学的最新成果,在空间协同区域化理论的基础上,对时空域中多元信息的协同克立格（ＳＴＣＯＫ）理论进行了较为详细的研究。主要研究内容有：（１）ＳＴＣＯＫ中的互变异函数与互协方差函数;（２）ＳＴＣＯＫ方程组及求解估值权因子的三种方法：①传统普通协同克立格法（ＳＴＴＯＣＯＫ）,②标准普通协同克立格法（ＳＴＳＯＣＯＫ）,③简单协同克立格法（ＳＴＳＣＯＫ）;（３）排列协同克立格（ＳＴＣＯＬＣＯＫ）;（４）指示协同克立格（ＳＴＩＫＣＯＫ）。 相似文献
6.
克立格法在采场品位估计中的应用 总被引：1，自引：1，他引：1
地下矿山的采场形态变化较大，且不规则，施行克立格法估值有一定的难度。本文从矿化模型的构造入手，了如何直接对地下矿山的采场实施克立格法估值，以便是要场储量，品位和估计精度。 相似文献
7.
8.
运用地质统计学计算研究区的实验变异函数,采用球状模型,拟合了研究区的理论变异函数;采用克立格法进行品位估值,运用Surpac建立了矿体的空间品位模型及矿床地质数学模型,并对其估值结果进行了有效性检验,结果与矿体实际情况基本吻合;充分利用矿床地质数学模型的各种数据信息,实现矿山资源储量动态管理。 相似文献
9.
次生晕数据的对数正态泛克立格法研究及异常评价 总被引：2，自引：0，他引：2
首先介绍了对数正态泛克立格法的基本理论和方法,包括对数正态分布,三参数对数正态分布,求解估值(Z_v)~*所需的权系数λ_α.及求解漂移值(m_v)~*所需的权系数ρ_α的对数正态泛克立格方程组.其次,笔者应用对数正态泛克立格法探讨了华北某测区的次生晕数据、元素统计分布特征以及变异函数及结构分析.最后,给出测区估计结果,元素综合异常图,划分出5个异常区,并结合地质条件对异常进行了综合评价. 相似文献
10.
胡小荣 《物探化探计算技术》1998,20(3):249-255
泛克立格法是地质统计学的一种重要估值方法,当区域化变量在空间变异几何域内非平稳时常用泛克立格法来估值。然而,用泛克立格方程组计算估计权值时由于未对权的符号作任何限制,从而使得计算出的权值经常出现负权现象,而负权的存在有许多弊端,所以在许多应用中有必要对权值作非负要求。本文基于线性规划方法提出了一种考虑权值非负约束的泛克立格算法,该算法既考虑到了权值的非负约束条件,又利用了线性规划方法求解简便快捷的优点。 相似文献
11.
Kriging of water levels in the Souss aquifer,Morocco 总被引：2，自引：0，他引：2
Universal kriging is applied to water table data from the Souss aquifer in central Morocco. The procedure accounts for the spatial variability of the phenomenon to be mapped. With the use of measured elevations of the water table, an experimental variogram is constructed that characterizes the spatial variability of the measured water levels. Spherical and Gaussian variogram models are alternatively used to fit the experimental variogram. The models are used to develop contour maps of water table elevations and corresponding estimation variances. The estimation variances express the reliability of the kriged water table elevation maps. Universal kriging also provides a contour map of the expected elevation of the water table (drift). The differences between the expected and measured water table elevations are called residuals from the drift. Residuals from the drift are compared with residuals obtained by more traditional least-squares analysis. 相似文献
12.
Importance of Orthogonalization Algorithm in Modeling Conditional Distributions by Orthogonal Transformed Indicator Methods 总被引：1，自引：0，他引：1
A. E. Tercan 《Mathematical Geology》1999,31(2):155-173
The orthogonal transformed indicator approach to conditional cumulative distribution functions is based on the decomposition of the indicator variogram matrix as a matrix product. This paper explores the manner in which the decomposition algorithm affects the conditional cumulative distribution function as estimated by orthogonal transformed indicator kriging. Five decomposition algorithms are considered: spectral, Cholesky, symmetric, Cholesky-spectral, and simultaneous decompositions. Impact of the algorithms on spatial orthogonality and order relations problems is examined and their performances together with indicator kriging are compared using a real dataset. 相似文献
13.
Chaolunbagen Hetai Liu TingxiDept. of Water Conservancy Inner M ongolia College of Agriculture Animal Husbandry Hohhot Nei M ongol Shang Ruoyun 《《地质学报》英文版》1995,69(2):197-207
A structural analysis of K of an aquifer system in the study area is presented, and the main direction and degree of the variability of K are found by using the unstationary regionalized variable theory of geostatistics. Optimal estimation of K has been made by universal kriging method (U K M ). Both spatial variability distribution map and division map of K are given. 相似文献
14.
Sample schemes used in geostatistical surveys must be suitable for both variogram estimation and kriging. Previously schemes
have been optimized for one of these steps in isolation. Ordinary kriging generally requires the sampling locations to be
evenly dispersed over the region. Variogram estimation requires a more irregular pattern of sampling locations since comparisons
must be made between measurements separated by all lags up to and beyond the range of spatial correlation. Previous studies
have not considered how to combine these optimized schemes into a single survey and how to decide what proportion of sampling
effort should be devoted to variogram estimation and what proportion devoted to kriging
An expression for the total error in a geostatistical survey accounting for uncertainty due to both ordinary kriging and variogram
uncertainty is derived. In the same manner as the kriging variance, this expression is a function of the variogram but not
of the sampled response data. If a particular variogram is assumed the total error in a geostatistical survey may be estimated
prior to sampling. We can therefore design an optimal sample scheme for the combined processes of variogram estimation and
ordinary kriging by minimizing this expression. The minimization is achieved by spatial simulated annealing. The resulting
sample schemes ensure that the region is fairly evenly covered but include some close pairs to analyse the spatial correlation
over short distances. The form of these optimal sample schemes is sensitive to the assumed variogram. Therefore a Bayesian
approach is adopted where, rather than assuming a single variogram, we minimize the expected total error over a distribution
of plausible variograms. This is computationally expensive so a strategy is suggested to reduce the number of computations
required 相似文献
15.
以浅剖数据为源数据,钻孔实测数据为验证数据,利用普通克里金法对海底地层厚度进行空间插值得到地层分布特征,采用3种半变异函数模型和不同取样间距对某井场3组地层厚度进行普通克里金插值并验证其插值效果。结果表明:普通克里金是一种有效的海底地层厚度预测方法;结构分析最佳的模型不一定是误差最小的模型,应对不同模型下的插值结果进行综合分析来选择最合适的模型,并提出球状模型在该井场厚度估计中最优,高斯模型次之;对于球状模型,增大取样间距对地层厚度变化剧烈的地层回归效果影响较小,对地层厚度变化不大的地层回归效果影响较大;同时,SE预测值变化率分析表明对于地层厚度变化剧烈的地层,减小取样间距可以大幅度地减少插值误差,而对于地层厚度变化不大的地层,减小取样间距对插值精度提高的意义不大。 相似文献
16.
地质统计学是数学地质领域最为活跃而实用的分支,它是以区域化变量理论为基础,以变异函数为基本工具,研究那些在空间分布上既具有随机性又具有结构性的自然现象的科学。在第四纪研究中的很多特征(变量)均可看成区域化变量进行地质统计学分析。作者在讨论了经典概率论及数理统计方法简单地应用于第四纪研究可能出现的问题后,着重介绍了用于第四纪研究中的若干地质统计学方法及基本理论,同时,对地质统计学方法应用于第四纪研究中的前景进行了分析。 相似文献
17.
I. C. Lemmer 《Mathematical Geosciences》1986,18(7):589-604
For any distribution of grades, a particular cutoff grade is shown here to exist at which the indicator covariance is proportional to the grade covariance to a very high degree of accuracy. The name “mononodal cutoff” is chosen to denote this grade. Its importance for robust grade variography in the presence of a large coefficient of variation—typical of precious metals—derives from the fact that the mononodal indicator variogram is then linearly related to the grade variogram yet is immune to outlier data and is found to be particularly robust under data information reduction. Thus, it is an excellent substitute to model in lieu of a difficult grade variogram. A theoretical expression for the indicator covariance is given as a double series of orthogonal polynomials that have the grade density function as weight function. Leading terms of this series suggest that indicator and grade covariances are first-order proportional, with cutoff grade dependence being carried by the proportionality factor. Kriging equations associated with this indicator covariance lead to cutoff-free kriging weights that are identical to grade kriging weights. This circumstance simplifies indicator kriging used to estimate local point-grade histograms, while at the same time obviating order relations problems. 相似文献
18.
《Applied Geochemistry》1999,14(1):133-145
Three univariate geostatistical methods of estimation are applied to a geochemical data set. The studied methods are: ordinary kriging (cross-validation), factorial kriging, and indicator kriging. These techniques use the probabilistic and spatial behaviour of geochemical variables, giving a tool for identifying potential anomalous areas to locate mineralization. Ordinary kriging is easy to apply and to interpret the results. It has the advantage of using the same experimental grid points for its estimates, and no additional grid points are needed. Factorial kriging decomposes the raw variable into as many components as there are identified structures in the variogram. This, however, is a complex method and its application is more difficult than that of ordinary or indicator kriging. The main advantages of indicator kriging are that data are used by their rank order, being more robust about outlier values, and that the presentation of results is simple. Nevertheless, indicator kriging is incapable of separating anomalous values and the high values from the background, which have a behaviour different to the anomaly. In this work, the results of the application of these 3 kriging methods to a set of mineral exploration data obtained from a geochemical survey carried out in NW Spain are presented. This area is characterised by the presence of Au mineral occurrences. The kriging methods were applied to As, considered as a pathfinder of Au in this area. Numerical treatment of Au is not applicable, because it presents most values equal to the detection limit, and a series of extreme values. The results of the application of ordinary kriging, factorial kriging and indicator kriging to As make possible the location of a series of rich values, sited along a N–S shear zone, considered a structure related to the presence of Au. 相似文献
19.
Kriging with imprecise (fuzzy) variograms. II: Application 总被引：2，自引：0，他引：2
The geostatistical analysis of soil liner permeability is based on 20 measurements and imprecise prior information on nugget effect, sill, and range of the unknown variogram. Using this information, membership functions for variogram parameters are assessed and the fuzzy variogram is constructed. Both kriging estimates and estimation variances are calculated as fuzzy numbers from the fuzzy variogram and data points. Contour maps are presented, indicating values of the kriged permeability and the estimation variance corresponding to selected membership values called levels. 相似文献
20.
The spatial distribution of cobalt-rich crust thicknesses on seamounts is partly controlled by water depth and slope gradients. Conventional distance–direction-based variogram have not effectively expressed the spatial self-correlation or anisotropy of the thicknesses of cobalt-rich crusts. To estimate resources in cobalt-rich crusts on seamounts using geostatistics, we constructed a new variogram model to adapt to the spatial distribution of the thicknesses of the cobalt-rich crusts. In this model, we defined the data related to cobalt-rich crusts on seamounts as three-dimensional surface random variables, presented an experimental variogram process based on the distance–gradient or distance–“relative water depth,” and provided a theoretical variogram model that follows this process. This method was demonstrated by the spatial estimation of the thicknesses of cobalt-rich crusts on a seamount, and the results indicated that the new variogram model reflects the spatial self-correlation of the thicknesses of cobalt-rich crusts well. Substituted into the Kriging equation, the new variogram model successfully estimated the spatial thickness distribution of these cobalt-rich crusts. 相似文献