广西农业干旱动态评估模型     

李艳兰  罗莹  黄雪松 《气象研究与应用》2006,27(2):11-14

以自然条件下大气-作物-土壤系统的水量平衡方程为基础,结合广西干旱灾害特点,建立广西农业干旱评估模型。与广西历史农业旱情实况对比分析表明,该模型能够较客观、定量地对农业干旱的发生、发展过程进行逐日动态监测和灾中、灾后评估。  相似文献   

理想点法在矿床工业价值评价中的应用     

王睿  张立新 《贵州地质》2006,23(4):282-285

应用理想点法的基本原理,建立了一个矿床工业价值评价的数学模型,以我国贵州省兴义市雄武地区铀矿床为实例,构造评价函数得出最优解,结果表明:理想点法能够正确评价出矿床工业价值的大小,为矿石的最优开采提供有价值的参考。  相似文献   

油藏地球化学原理及其在油气勘探与油藏评价中的应用   总被引：1，自引：0，他引：1  

张枝焕  杨永才  李伟 《海相油气地质》2006,11(4):39-47

综合评述了近年来油藏地球化学基础研究方面的主要进展,包括油气藏内流体非均质性成因、烃充注成藏及混合作用模式、储层内流体与岩石相互作用、油藏内烃的地球化学变化等,阐述了烃族群划分及其地球化学意义。结合实例介绍了油藏地球化学在油气勘探、油藏评价与油田生产管理中的主要应用领域与研究现状。在油气勘探领域的应用主要包括烃运移方向的地球化学研究、烃成藏时间及期次的确定、古油水界面的判别等;在油藏评价和油田生产管理方面的应用主要有油藏流体的连通性和分隔性研究、混合开采油藏单层产能贡献研究以及油、水、干层的地球化学识别等。  相似文献   

Observed oil and gas field size distributions: A consequence of the discovery process and prices of oil and gas     

Lawrence J. Drew  Emil D. Attanasi  John H. Schuenemeyer 《Mathematical Geology》1988,20(8):939-953

If observed oil and gas field size distributions are obtained by random samplings, the fitted distributions should approximate that of the parent population of oil and gas fields. However, empirical evidence strongly suggests that larger fields tend to be discovered earlier in the discovery process than they would be by random sampling. Economic factors also can limit the number of small fields that are developed and reported. This paper examines observed size distributions in state and federal waters of offshore Texas. Results of the analysis demonstrate how the shape of the observable size distributions change with significant hydrocarbon price changes. Comparison of state and federal observed size distributions in the offshore area shows how production cost differences also affect the shape of the observed size distribution. Methods for modifying the discovery rate estimation procedures when economic factors significantly affect the discovery sequence are presented. A primary conclusion of the analysis is that, because hydrocarbon price changes can significantly affect the observed discovery size distribution, one should not be confident about inferring the form and specific parameters of the parent field size distribution from the observed distributions.This paper was presented at Emerging Concepts, MGUS-87 Conference, Redwood City, California, 13–15 April 1987.  相似文献   

Dynamic changes of habitats in China’s typical national nature reserves on spatial and temporal scales     

Ping Zhu  Lin Huang  Tong Xiao  Junbang Wang 《地理学报(英文版)》2018,28(6):778-790

Until 2015, China had established 2740 nature reserves with a total area of 1.47 million km², covering 14.8% of China’s terrestrial land surface. Based on remote sensing inversion, ecological model simulation and spatial analysis methods, we analyzed the spatial and temporal variations of fractional vegetation coverage (FVC), net primary production (NPP), and human disturbance (HD) in habitats of typical national nature reserves (NNRs) during the first 15 years of the 21st century from 2000 to 2015. And then the three indicators were compared between different NNR types and varied climate zones. The results showed that (1) the average 5-year FVC of NNRs increased from 36.3% to 37.1%, and it improved in all types of NNRs to some extent. The annual average FVC increased by 0.11%, 0.84%, 0.21%, 0.09%, 0.11% and 0.08% in NNRs of forest ecosystem, plain meadow, inland wetland, desert ecosystem, wild animal and wild plant, respectively. (2) The NPP annually increased by 2.06 g·m^-2, 1.23 g·m^-2, 0.28 g·m^-2 and 0.4 g·m^-2 in NNRs of plain meadow, inland wetland, desert ecosystem and wild animal, respectively. However, it decreased by 3.45 g·m^-2 and 2.35 g·m^-2 in NNRs of forest ecosystem and wild plant respectively. (3) In the past 15 years, besides the slight decreases in the NNRs located at the Qinghai-Tibet Plateau and the south subtropical zone, HD enhanced in most of NNRs, especially HD in the warm temperate humid zone increased from 4.7% to 5.35%.  相似文献   

Effect Blasting Excavation of Yujiapeng Tunnel on Stability of Nearby Giant Dangerous Rock Masses (DRM)     

Yu Hongming Hu Yanxin Engineering Faculty  China University of Geosciences  Wuhan 《中国地质大学学报(英文版)》2001,12(2)

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复杂结构煤层储量经济可采性分析：以五家煤矿为例     

范广忱 《煤田地质与勘探》1992,20(6):25-27

基于五家煤矿多年的生产经验及大量实际资料,作者提出了一种分析经济可采储量的思路和计算方法,指出复杂结构煤层储量的工业价值并不取决于煤层储量的大小。并用这个思路和方法对该矿现存储量进行经济可采性分析,缓和了生产与储量管理间的矛盾,为矿区建设及发展提供了较科学的依据,并在实践中取得了预期效果。  相似文献   

Quantitative assessment of mineral resources with an application to petroleum geology   总被引：2，自引：0，他引：2  

J. Harff  J. C. Davis  R. A. Olea 《Natural Resources Research》1992,1(1):74-84

The probability of occurrence of natural resources, such as petroleum deposits, can be assessed by a combination of multivariate statistical and geostatistical techniques. The area of study is partitioned into regions that are as homogeneous as possible internally while simultaneously as distinct as possible. Fisher's discriminant criterion is used to select geological variables that best distinguish productive from nonproductive localities, based on a sample of previously drilled exploratory wells. On the basis of these geological variables, each wildcat well is assigned to the production class (dry or producer in the two-class case) for which the Mahalanobis' distance from the observation to the class centroid is a minimum. Universal kriging is used to interpolate values of the Mahalanobis' distances to all locations not yet drilled. The probability that an undrilled locality belongs to the productive class can be found, using the kriging estimation variances to assess the probability of misclassification. Finally, Bayes' relationship can be used to determine the probability that an undrilled location will be a discovery, regardless of the production class in which it is placed. The method is illustrated with a study of oil prospects in the Lansing/Kansas City interval of western Kansas, using geological variables derived from well logs.  相似文献   

Developing a geographic expert system for regional mapping of volcanogenic massive sulfide (VMS) deposit potential     

R. K. T. Reddy  G. F. Bonham-Carter  A. G. Galley 《Natural Resources Research》1992,1(2):112-124

A personal computer-based geographic information system (GIS) is used to develop a geographic expert system (GES) for mapping and evaluating volcanogenic massive sulfide (VMS) deposit potential. The GES consists of an inference network to represent expert knowledge, and a GIS to handle the spatial analysis and mapping. Evidence from input maps is propagated through the inference network, combining information by means of fuzzy logic and Bayesian updating to yield new maps showing evaluation of hypotheses. Maps of evidence and hypotheses are defined on a probability scale between 0 and 1. Evaluation of the final hypothesis results in a mineral potential map, and the various intermediate hypotheses can also be shown in map form.The inference net, with associated parameters for weighting evidence, is based on a VMS deposit model for the Chisel Lake deposit, a producing mine in the Early Protoerzoic Snow Lake greenstone belt of northwest Manitoba. The model is applied to a small area mapped at a scale of 1:15,840. The geological map, showing lithological and alteration units, provides the basic input to the model. Spatial proximity to contacts of various kinds are particularly important. Three types of evidence are considered: stratigraphic, heat source, and alteration. The final product is a map showing the relative favorability for VMS deposits. The model is implemented as aFortran program, interfaced with the GIS. The sensitivity of the model to changes in the parameters is evaluated by comparing predicted areas of elevated potential with the spatial distribution of known VMS occurrences.  相似文献   

基于3S 技术的土地执法共同责任考核模型设计及系统实现--以深圳市为例     

林文娟  常鹏飞  刘赟  林楚彬 《测绘工程》2016,25(6):65-69

基于3S技术和土地执法共同责任考核制度,设计满足共同责任考核计算规则的考核模型;结合深圳市规划土地数字监察平台,基于空间分析技术,建立土地执法共同责任考核系统,为实现全过程量化指标的土地执法共同责任考核模式提供更为准确、客观的参考依据及技术支撑。  相似文献