【作者】 邓浩；

【导师】 毛先成；

【作者基本信息】 中南大学 ， 地图学与地理信息系统， 2008， 硕士

【摘要】 矿产资源预测与评价逐渐进入基于GIS技术定量预测与评价的新阶段,GIS已成为矿产资源预测与评价定量化的核心技术。传统的二维GIS只能表达面上的信息,对于大比例尺下的隐伏矿体预测中矿床的三维空间信息往往不能很自然地表达与分析。三维GIS和三维地学建模系统的出现弥补了二维GIS的不足,使对地质对象进行真三维表达成为可能。然而在这种真三维空间数据环境下的矿产资源定量预测与评价过程中,需要有高效与稳健的三维地质建模和三维空间分析技术来支撑。论文首先对隐伏矿体预测中三维地质建模技术进行了研究,讨论了地质对象的空间数据表达,给出了一种通过表面建模建立地质体几何轮廓,由体素模型表达地质体,将体素模型以线性八叉树存储的解决方案。为了满足大规模地质体高分辨率下线性八叉树建模的需要,论文提出了一种硬件加速条件下的由面表示模型动态生成线性八叉树算法。算法利用深度缓存判断体元在实体内外,通过栈结构来存储八叉树分解的情况,在对栈的操作中输出编码,省去了结点的排序和压缩过程。进一步利用深度缓存中的信息,算法对实体进行了分块,并按分块构造线性八叉树达到加速效果。实验结果表明线性八叉树生成过程可以在高分辨率下快速地执行。为了满足地质控矿指标定量提取的需要,论文对隐伏矿体预测中基于体素模型的空间分析若干技术进行了研究。首先给出了一种适用于离散化三维地质空间的距离分析方法,该方法通过欧式距离变换生成欧式距离场进行量算。基于数学形态学滤波,论文提出了一种地质体趋势形态分析方法;论文利用欧式距离场与数学形态学对地质体形态起伏分析方法进行了研究,提出了一种对地质体形态起伏进行分级定量提取的方法。论文以数学形态学膨胀运算的原理生成空间实体的栅格缓冲体,提出了一种基于GPU的栅格缓冲体生成算法。基于这些空间分析方法,论文还对地质控矿作用模拟进行了研究,模拟了地质体控矿作用,岩体-围岩理想接触带控矿作用和接触面间倾角。更多还原

【Abstract】 The prediction and evaluation of mineral resources gradually enter a new stage of quantitative prediction and evaluation using GIS techniques, while GIS has become core techniques of quantitative prediction and evaluation of mineral resources. Traditional two-dimensional GIS can only represent information based on face. For three-dimensional spatial information of deposits in the prediction of buried ore bodies at large-scale, 2D GIS can not represent and analysis very well. This shortcoming in 2D GIS can be overcome by three-dimensional GIS and 3D geological modeling system, in which geological objects can be true 3D represented. Under these true 3D spatial data environment, however, the procedure of prediction and evaluation of mineral resources needs the efficient and robust techniques of 3D geological modeling and 3D spatial analysis to support.First the techniques of 3D geological modeling in the prediction of buried ore bodies were studied. The spatial data representations of geological objects were discussed. The paper gives a solution in which the geometric contours of geological body were built by surface modeling while geological body were represented by voxel model, and stored in linear octrees. In order to meet the needs of high-resolution modeling of massive geological bodies, moreover, a hardware accelerated algorithm which can generate linear octrees dynamically from surface representation models was presented. In the algorithm, depth buffers were used to determine whether a voxel is inside or outside a 3D object, a stack structure were used to store the decomposition status of octree, and the codes are exported during the stack operation so the sort and compression of nodes is avoided. The depth buffers are further used to divide the object. Based on this division, the construction of linear octree can be accelerated. The result shows the process of linear octree generation can be run fairly fast under high resolution.To meet the needs of quantitative extraction of ore-controlling indicators, the paper studied some techniques on voxel model based spatial analysis in the prediction of buried ore bodies. A distance analysis method is proposed which is suitable in concrete three-dimensional geological space. In this method Euclidean distance transform is employed to generate Euclidean distance field. Moreover, the paper presents a morphological filtering based algorithm which can get trend shape of geological body. Based on Euclidean distance field and mathematical morphology, the method for morphological character of geological body was studied. By using the method given in study, the undulant range of morphological changes of geological body can be sebquential extracted. Furthermore, employing dilation operation in mathematical morphology to generate raster buffer of an objects, the paper presents a GPU based algorithm for raster buffer generation. Based on these techniques for spatial analysis, the study also focused on modeling the geological ore-controlling actions, which included modeling ore-controlling actions of geological bodies, the contact zone of rock and country rocks, and modeling the angles of contact surfaces.更多还原