岩土性质的空间信息统计分析

运用地质统计学的原理与方法 ,以变差函数为工具 ,在工程实测数据的基础上对静止水位进行了分析 ,得到不同方向上的实验变差函数及理论变差函数模型 ,并提出了一个变异性综合指标 ,实现了对岩土性质空间变异性的定量化分析。     

基于局部地表形态的可变过水宽度多流向算法

流向是地形分析中的重要内容之一,在分布式水文模型等研究中起着重要作用。文章提出基于局部地表形态的多流向算法,即对每一个DEM栅格,在以其为中心的3×3窗口中进行局部地形分析,确定基于随坡度和过水宽度而变化的水流分配系数。该方法被应用在实际数字地形模型上,并以汇水面积和比汇水面积为研究指标,与目前流行的D8、Dinf等算法进行了相似性分析。结果表明,该方法能够获得更为符合实际的水流汇集的空间分布。     

Using Dummy Variables to Estimate Economic Base Multipliers

Economic base analysis is a cost-effective and accurate means of predicting employment impacts in relatively small and uncomplicated regional (community) economies. Extending previous research using the Arizona Community Data Set, this paper estimates economic base multipliers in different types of communities by introducing dummy variables into regression equations. Total employment, transfer payments, and population potential are used as explanatory variables. Manufacturing centers are shown to have larger multipliers than diversified places, mining settlements, service and trade communities, and utility towns.     

深切河谷区地应力场测试数据的统计分析

以某深切峡谷区应力解除法和水压致裂法实测数据为基础资料，运用统计分析方法对该区河谷和岸坡中的地应力场的特征进行分析，分别获得了整个坝区、河谷区和岸坡中最大水平应力的方向，以及河谷区最大水平应力量值与埋深的拟合方程。并根据岸坡中地应力场的变化特征，对空间地应力测试数据进行了筛选，最终获得了代表岸坡相对稳定区的地应力场的量值和方向。     

几何不等式问题的推广及应用

本文对几何不等式问题做些推广，并提出了广义几何不等式，通过构造随机变量，利用随机变量数学期望的概率性质，给出几何不等式及广义几何不等式的概率证明，最后给出几何不等式的一个直接应用，所得的结果是文献（１－４）的补充和拓广。     

Teacher''s Aide: Geologic Characteristics of Hole-Effect Variograms Calculated from Lithology-Indicator Variables

Variograms calculated from binary variables, such as from two lithologies, tend to show sinusoidal forms with decreasing amplitudes for increasing lag distances. This cyclicity is observed often when analyzing drill-hole data for rock sequences with alternating lithologies, and the variograms are thus labeled hole-effect variograms. Such variograms show a variety of forms: (1) Low to moderate variation in lithologic-body dimensions causes variograms to have strong cyclicity with decaying amplitude. (2) Variograms with one or more peaks and troughs usually result from a binary variable for which lithologies are about equally abundant but possibly large variations exist in the size of lithologic bodies. (3) Variograms show poor cyclicity if one lithology has highly variable body sizes and the other has moderately variable body dimensions. (4) Variograms that attain a plateau at short lag distances represent extremely high or low sandstone fraction, high variability in size of the most abundant lithology, and low variability in the other. Information about the dimensions of lithologic bodies makes it possible to approximate characteristics of the variogram of the lithology variable without numerous wells. Conversely, a hole-effect variogram of lithology may be used to estimate lithologic dimensions.     

基于自适应可变滤镜的地类变化预测模型

随着土地开发建设规模不断扩大,土地利用情况也在逐年发生变化,准确预测未来土地利用的发展趋势,可以为本地区的土地利用规划提供依据,提升本地区的土地利用效率。传统方法一般采用CA_Markov、ANN以及CA_ANN模型进行预测,存在训练时间长、预测精度不足和缺乏说服力等问题。本文针对上述问题,结合元胞自动机以及人工神经网络模型,建立一种自适应可变滤镜网络模型,针对特定大小区域内的土地类别数目,创建多类数据集来训练不同参数的多个神经网络,可以成功预测未来土地变化的情况,这样就避免了训练单一网络时数据对网络权值的抵消。相比于传统模型中效果最好的CA_ANN模型,本文建立的自适应可变滤镜网络模型不仅总体精度提高了1%~3%,各种地类转化精度提高了12.82%~33.33%,模型预测时间也缩减了49.47%。     

Statistical mineral prediction without defining a training area

Statistical mineral prediction without defining a training area is one of the most important problems in mathematical geology. A mineralized favorability index (MFI) model is proposed. It is assumed that a certain geological environment related to the ore deposits or bodies considered can be described by a snythesis variable Y=_ix_i, where x_i (i=1 ... k) are k geological variables and _i are the weights, respectively. Y and _i are to be estimated. The study area is divided into equal-sized cells and assessed by comparing the Y values in the cells with each other.This paper is based on the main result of the author's master thesis, Wuhan College of Geology, Wuhan, China     

水文地质变异因素的定量分析——方差分析在水文地质工作中的应用

能引起地下水质量或数量发生变化的因素很多。这些因素可能单独作用于地下水,也可能交互作于用地下水。通过方差分析可以定量评价某个变异因素的影响是否显著;在有重复试验的条件下,两个变异因素的方差分析还可以确定有无交互作用。此外,通过多重比较还可以进一步确定某个变异因素对地下水的影响程度。     

划分重力区域异常与局部异常的变阶滑动趋势分析法

本文在分析一般趋势分析缺陷的基础上,提出了变阶滑动趋势分析法,并用正交变换代替趋势分析中的解线性方程组,避免了线性方程组病态而造成的异常失真。最后用理论模型和实际资料处理结果说明了变阶滑动趋势分析的优点。