GIS分析中的地理模式

GIS的强大之处在于其分析功能,GIS分析是一个从地理数据中发现地理模式和要素间关系的过程.然而,对大多数用户而言,GIS分析显得难以入门,这一方面是由于GIS分析的困难性和复杂性,另一方面则由于相关的教育和培训机构对GIS分析的基础--地理模式的忽视.基于这个原因,介绍了地理模式的两种基本元素和主要的几种基本类型,并且论述了从地理数据中发现地理模式的过程.     

2010年4月14日玉树7.1级地震前异常特征及强震动力学关系探讨

系统地分析了2010年4月14日玉树7.1级地震的地震活动性异常、前兆异常以及震前动物反常行为.研究表明,玉树7.1级地震前异常并不丰富,但觉察到的异常突出.其中中长期异常有6级、5级和4级的平静区;前兆观测有玉树表层水温、德令哈表层水温和平安电磁波等显著异常;同时震前1周还存在数量较多的动物宏观异常现象;主震前130min发生了一次4.7级地震.结合1996年以来巴颜喀拉地块边界的强震震源机制解,探讨了玉树地震孕育的动力学过程.结果表明,1996年喀喇昆仑山口7.1级、1997年玛尼7.5级和2010年玉树7.1级地震是同一动力学过程下的强震事件,且中长期存在的不同震级档平静区演化可能与上述动力学过程有关.还对强震原地复发、前震识别和玉树地震中的前兆观测等科学问题进行了讨论.     

改进不等时距权重的灰色残差组合修正模型及其应用

为提高传统不等时距灰色模型(TUTGM)的预测精度,提出了一种改进不等时距权重的灰色残差组合修正模型(IUTWGMRCC)。首先在传统不等时距灰色模型中引入时距权重分配系数,按照累加生成和累减还原过程的生成序列不同,构建了4种不同的预测模型,并依据相似度准则确定最优拟合序列和预测值;然后采用正弦函数和谐波变化生成的周期序列函数修正残差序列,进一步提高模型的预测精度;最后对建筑物3个观测点的沉降量进行预测。结果表明,累减还原过程引入不等时距权重的灰色模型预测精度最高,经残差组合修正后,预测结果的后验差比分别为0.04、0.11和0.05,精度等级为1级。     

海洋矢量过程旋转谱估计的统计分布及置信区间

本文利用一些复随机变量的分布和统计推断理论,导出了向量过程的正旋谱、负旋谱、谱差、总谱、外自谱、频域外自相关函数、外自谱的位相函数等估计量的渐近分布以及它们的置信区间,并简略地讨论了所得置信区间的最优性。最后用锚系海流计资料实例说明了所得置信区间公式在海流资料分析中的应用。     

基于MAPGISG平台的中国地学断面数字化图形库的建立

地学断面积累了丰富的地质，地球物理和地球化学等综合资料，从中得出的地学信息是提供科学决策，促进社会科技事业和生产力发展的依据。在MAPGIS软件基础上的中国地学断面数字化图形库的建立过程中，地学断面中的每一个实体，在颜色，符号以及线型等方面都被规划统一。地学断面中的特征主题进行了层名划分以及层名，实体的编码，形成分层标准和编码准则。利用MAPGIS的编辑子系统和Access关于数据库软件，建立了中国地学断面的空间数据库和属性数据库，并将它们联接起来，从而建立了整个中国地学断面数字化图形库。     

Reservoir prediction using multi-wave seismic attributes

The main problems in seismic attribute technology are the redundancy of data and the uncertainty of attributes, and these problems become much more serious in multi-wave seismic exploration. Data redundancy will increase the burden on interpreters, occupy large computer memory, take much more computing time, conceal the effective information, and especially cause the "curse of dimension". Uncertainty of attributes will reduce the accuracy of rebuilding the relationship between attributes and geological significance. In order to solve these problems, we study methods of principal component analysis (PCA), independent component analysis (ICA) for attribute optimization and support vector machine (SVM) for reservoir prediction. We propose a flow chart of multi-wave seismic attribute process and further apply it to multi-wave seismic reservoir prediction. The processing results of real seismic data demonstrate that reservoir prediction based on combination of PP- and PS-wave attributes, compared with that based on traditional PP-wave attributes, can improve the prediction accuracy.     

RUPTURE CHARACTERISTICS OF LATE QUATERNARY STRONG EARTHQUAKES ON THE WESTERN BRANCH OF THE XIAOJIANG FAULT ZONE

The Xiaojiang fault zone is located in the southeastern margin of the Tibetan plateau, the boundary faults of Sichuan-Yunnan block and South China block. The largest historical earthquake in Yunnan Province, with magnitude 8 occurred on the western branch of the Xiaojiang Fault in Songming County, 1833. Research on the Late Quaternary surface deformation and strong earthquake rupture behavior on the Xiaojiang Fault is crucial to understand the future seismic risk of the fault zone and the Sichuan-Yunnan region, even crucial for the study of tectonic evolution of the southeastern margin of Tibetan plateau. We have some new understanding through several large trenches excavated on the western branch of the Xiaojiang fault zone. We excavated a large trench at Caohaizi and identified six paleoseismic events, named U through Z from the oldest to the youngest. Ages of these six events are constrained at 40000-36300BC, 35400-24800BC, 9500BC-500AD, 390-720AD, 1120-1620AD and 1750AD-present. The Ganhaizi trench revealed three paleoearthquakes, named GHZ-E1 to GHZ-E3 from the oldest to the youngest. Ages of the three events are constrained at 3300BC-400AD, 770-1120AD, 1460AD-present. The Dafendi trench revealed three paleoearthquakes, named E1 to E3 from the oldest to the youngest, and their ages are constrained at 22300-19600BC, 18820-18400BC, and 18250-present. Caohaizi and Ganhaizi trenches are excavated on the western branch of the Xiaojiang Fault, the distance between them is 400m. We constrained four late Holocene paleoearthquakes with progressive constraining method, which are respectively at 500-720AD, 770-1120AD, AD 1460-1620 and 1833AD, with an average recurrence interval of 370~440a. Large earthquake recurrence in the late Holocene is less than the recurrence interval of~900a as proposed in the previous studies. Thus, the seismic hazard on the Xiaojiang Fault should be reevaluated. We excavated a large trench at Dafendi, about 30km away south of Caohaizi trench. Combining with previous paleoseismological research, it is found that the western branch of Xiaojiang Fault was likely to be dominated by segmented rupturing in the period from late of Late Pleistocene to early and middle Holocene, while it was characterized by large earthquakes clustering and whole segment rupturing since late Holocene.     

Geological characteristics and co-exploration and co-production methods of Upper Permian Longtan coal measure gas in Yangmeishu Syncline,Western Guizhou Province,China

Coal measure gas (also known as coal-bearing unconventional gas) is the key field and development direction of unconventional natural gas in recent years. The exploration and evaluation of coal measure gas (coalbed methane, coal shale gas and coal measure tight sandstone gas) from single coalbed methane has greatly expanded the field and space of resource evaluation, which is of positive significance for realizing the comprehensive utilization of coal resources, maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development. For the first time, in Yangmeishu Syncline of Western Guizhou Province, the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation, identified the geological conditions of coal measure gas and found high quality resources. The total geological resource quantity of coalbed methane and coal shale gas is 51.423×10⁹ m³ and the geological resource abundance is up to 566×10⁹ m³/km². In this area, the coal measures are characterized by many layers of minable coal seams, large total thickness, thin to the medium thickness of the single layer, good gas-bearing property of coal seams and coal measure mudstone and sandstone, good reservoir physical property and high-pressure coefficient. According to the principle of combination of high quality and similarity of key parameters of the coal reservoir, the most favorable intervals are No.5⁻², No.7 and No.13⁻² coal seam in Well YMC1. And the pilot tests are carried out on coal seams and roof silty mudstone, such as staged perforation, increasing hydraulic fracturing scale and “three gas” production. The high and stable industrial gas flow with a daily gas output of more than 4000 m³ has been obtained, which has realized the breakthrough in the geological survey of coal measure gas in Southwest China. Based on the above investigation results, the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the co-exploration and co-production methods, such as the optimization method of favorable intervals, the high-efficiency fracturing and reservoir reconstruction method of coal measures, and the “three gas” drainage and production system, are systematically summarized in this paper. It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.     

区间值直观模糊集的直积与相关性

在区间值直观模糊集上定义新的算子,给出这些关系与算子之间的一些重要性质,并讨论了区间值直观模糊集的相关性问题.     

京山县土地利用更新调查数据库建设编制研究

结合京山县土地利用更新调查数据库建设的生产实际,对编制过程中图宽净面积小于等于零、行政辖区面积和图斑计算面积不一致等问题产生的原因进行了分析,说明了应该如何避免这些问题的发生,阐述了所采用的利用图例板自带的属性自动赋值、计算机自动赋值、外来数据挂接赋值和手工输入赋值等4种属性数据录入方式和通过条件生成点文件功能对零星地物的录入处理。