变差函数在赣杭构造带火山岩型铀矿田(床)评价中的应用     

李瀚波  潘蔚  毛玉仙 《铀矿地质》2010,26(5):301-305

在简要介绍变差函数的原理、算法和研究区地质情况的基础上,将变差函数引入火山岩型铀成矿作用与地形相关性研究中。详细描述了赣杭构造带中不同成矿规模矿田(床)区地形高程变差统计的过程,初步分析了变差统计结果的地质意义。研究结果表明,地形高程值变差函数的长轴方向可以反映研究区的主要构造方向,变差函数的长短轴半径与铀矿床的成矿规模在一定程度上具有对应关系。  相似文献   

Characterizing landscape spatial heterogeneity in multisensor images with variogram models     

Bingwen Qiu  Canying Zeng  Chongcheng Cheng  Zhenghong Tang  Jianyang Gao  Yinpo Sui 《中国地理科学(英文版)》2014,24(3):317-327

Most evaluation of the consistency of multisensor images have focused on Normalized Difference Vegetation Index （NDVI） products for natural landscapes, often neglecting less vegetated urban landscapes. This gap has been filled through quantifying and evaluating spatial heterogeneity of urban and natural landscapes from QuickBird, Satellite pour l＇observation de la Terre （SPOT）, Ad- vanced Spacebome Thermal Emission and Reflection Radiometer （ASTER） and Landsat Thematic Mapper （TM） images with variogram analysis. Instead of a logarithmic relationship with pixel size observed in the corresponding aggregated images, the spatial variability decayed and the spatial structures decomposed more slowly and complexly with spatial resolution for real multisensor im- ages. As the spatial resolution increased, the proportion of spatial variability of the smaller spatial structure decreased quickly and only a larger spatial structure was observed at very coarse scales. Compared with visible band, greater spatial variability was observed in near infrared band for both densely and less densely vegetated landscapes. The influence of image size on spatial heterogeneity was highly dependent on whether the empirical sernivariogram reached its sill within the original image size. When the empirical semivariogram did not reach its sill at the original observation scale, spatial variability and mean characteristic length scale would increase with image size; otherwise they might decrease. This study could provide new insights into the knowledge of spatial heterogeneity in real multisen- sor images with consideration of their nominal spatial resolution, image size and spectral bands.  相似文献   

顾及空间相关性的遥感影像信息量的度量方法   总被引：1，自引：1，他引：0  

张盈  张景雄 《测绘学报》2015,44(10):1117-1124

提出了一种结合信息论与地学统计法的遥感影像信息量计算的方法。此方法基于遥感影像加性噪声模型和互信息上界的计算原理,同时考虑了噪声和空间相关性等影响遥感影像信息量的因素,适于计算具有稳健空间相关性、不同地物类型的光学影像的信息含量。利用Landsat TM影像子集,分别计算了城市、农田、山地3种不同地物类型的影像信息量。结果表明,城市含有最大的信息量,同时影像信息量与影像方差呈对数正相关关系。  相似文献   

滑动窗口的普通克立格方法在降水量插值中的应用     

熊敏诠 《气象》2013,39(4):486-493

利用2009年全国2200个观测站降水量资料,使用滑动窗口的普通克立格方法对降水量资料进行格点化估计。针对滑动窗口的普通克立格方法在降水量格点化应用中存在的问题,设计了3种技术处理的试验方案。比较了全局搜索与方位邻近方法的误差,讨论了最大影响半径及屏蔽效应对插值效果的作用。提出了方位邻近法的样本点选择策略,结果表明,相对传统滑动窗口的普通克立格方法较常使用的全局搜索法而言,方位邻近法显著降低了计算资源的耗用,同时又具有较高的插值精度,特别是在站点密集地区有突出的优势;试验结果也表明:变程为4°～5°的经(纬)线弧长时,在方位邻近法下,我国大部分区域有较好的插值效果;屏蔽效应弱,ε取值为0.1时,降水量插值准确率较高,随着ε增大,插值误差也逐渐增大。  相似文献   

Exact formulas for approximating variogram function integrals     

Mark R. Dunn  H. Dennis Tolley  J. Richard Alldredge 《Mathematical Geology》1980,12(6):577-588

The application of regionalized variables requires the estimation of the variogram function and the evaluation of its integral. By representing the variogram by a polygonal function the integral may be easily approximated by closed form representations of polygonal integrals. This approach provides a basis for more extensive statistical evaluation not evident in existing approximation methods. This paper provides the closed form representations for two-dimensional variogram functions whose domain is represented by a finite collection of rectangles.  相似文献   

Random vectors and spatial analysis by geostatistics for geotechnical applications     

Dae S. Young 《Mathematical Geology》1987,19(6):467-479

Geostatistics is extended to the spatial analysis of vector variables by defining the estimation variance and vector variogram in terms of the magnitude of difference vectors. Many random variables in geotechnology are in vectorial terms rather than scalars, and its structural analysis requires those sample variable interpolations to construct and characterize structural models. A better local estimator will result in greater quality of input models; geostatistics can provide such estimators: kriging estimators. The efficiency of geostatistics for vector variables is demonstrated in a case study of rock joint orientations in geological formations. The positive cross-validation encourages application of geostatistics to spatial analysis of random vectors in geoscience as well as various geotechnical fields including optimum site characterization, rock mechanics for mining and civil structures, cavability analysis of block cavings, petroleum engineering, and hydrologic and hydraulic modelings.  相似文献   

A comparison between cokriging and ordinary kriging: Case study with a polymetallic deposit     

Guocheng Pan  Dave Gaard  Ken Moss  Tim Heiner 《Mathematical Geology》1993,25(3):377-398

Cokriging is applied to the estimation of mineral resources in a polymetallic deposit. Several major steps, which should be taken in using cokriging, are highlighted as necessary practical considerations. The case study is related to an ultramafic copper-nickel deposit. Six elements, Cu, Ni, Au, Ag, Pt, and Pd, occurring in the deposit, are partitioned into three subgroups and the elements within each group are simultaneously estimated on the basis of over 4000 drill assays. A comparison was made between ordinary kriging and cokriging methods through cross-validation. The results show that cokriging has significantly improved the estimates of resources by reducing the overall estimation error by over 15% and the variance of error by over 20%.  相似文献   

Testing variograms for positive-definiteness     

Margaret Armstrong  Phil Diamond 《Mathematical Geology》1984,16(4):407-421

A method based on Bochner's theorem is described for demonstrating the positive-definiteness of variogram models and for generating classes of valid variogram functions.Work performed while on leave at the Centre de Géostatistique et de Morphologie Mathématique.  相似文献   

变异函数模型参数的非线性加权总体最小二乘法     

赵英文  王乐洋  陈晓勇  鲁铁定 《测绘科学》2017,42(1)

针对球状模型和指数模型两种变异函数模型线性化后的系数矩阵具有非线性形式,系数矩阵元素含有随机误差等问题,该文使用非线性加权总体最小二乘法估计变异函数模型参数。以高程异常数据为例,利用变异函数值的点对数定权法和系数矩阵中距离值的方差-协方差传播律定权法迭代解算参数,并与最小二乘法,加权最小二乘法和非线性总体最小二乘法进行对比分析。实验结果表明:非线性加权总体最小二乘法能够得到更高精度的变异函数模型参数。  相似文献   

中国旅游经济空间格局演变特征及其影响因素分析   总被引：8，自引：4，他引：4  

吴媛媛  宋玉祥 《地理科学》2018,38(9):1491-1498

基于中国地级单元2005~2015年旅游经济及相关指标的面板数据,运用ESDA、空间变差函数、空间计量方法,揭示中国旅游经济空间格局演变特征及影响因素。结果表明：① 中国旅游经济空间相关性显著为正,高高和低低集聚现象明显。高高集聚区分布在三大经济区以及闽东沿海地区内,低低集聚区分布在西部地区及东北北部地区。② 中国旅游经济空间差异不断减小,旅游外汇和国内旅游收入分别在东南-西北和东-西方向上空间差异最大。③ 经济发展水平、旅游资源禀赋、旅游服务设施、交通条件、信息化程度共同影响着中国旅游经济空间格局的形成与演变。  相似文献