Spectral Simulation and Conditioning to Local Continuity Trends in Geologic Modeling

Spectral simulation has gained application in building geologic models due to the advantage of better honoring the spatial continuity of petrophysical properties, such as reservoir porosity and shale volume. Distinct from sequential simulation methods, spectral simulation is a global algorithm in the sense that a global density spectrum is calculated once and the inverse Fourier transform is performed on the Fourier coefficient also only once to generate a simulation realization. The generated realizations honor the spatial continuity structure globally over the whole field instead of only within a search neighborhood, as with sequential simulation algorithms. However, the disadvantage of global spectral simulation is that it traditionally cannot account for the local information such as the local continuity trends, which are often observed in reservoirs and hence are important to be accounted for in geologic models. This disadvantage has limited wider application of spectral simulation in building geologic models. In this paper, we present ways of conditioning geologic models to the relevant local information. To account for the local continuity trends, we first scale different frequency components of the original model with local-amplitude spectrum ratios that are specific to the local trend. The sum of these scaled frequency components renders a new model that displays the desired local continuity trend. The implementation details of this new method are discussed and examples are provided to illustrate the algorithm.     

Fission track evidence for the Mesozoic Cenozoic tectonic uplift of Mt. Bogda, Xinjiang, Northwest China

1 IntroductionThe Mesozoic-Cenozoic tectonic evolution and ki-netics mechanism of the intracontinental orogen are thekey subjects of continental dynamics (Ma Zongjin andGao Xianglin, 2004) and the key to understanding theregional geological tectonics (Qia…     

河南省平顶山盐田盐矿床成矿特征探讨

以现有钻孔及区域资料为基础，对平顶山盐田盐矿床形成的构造条件和盐湖的沉积模式、沉积类型成矿物源进行了分析，为平顶山盐田的进一步勘查和开发提供了宝贵资料。     

基于VRMap平台上的电子沙盘研制

通过与国内外数字沙盘制作方式及功能的比较，详细介绍了数字沙盘研究方面的一些方法，并以中原油田数字沙盘的研制为例，选择北京灵图公司的VRMap2．3软件作为平台制作中原油田数字沙盘，为油田开发提供基本资料。     

How Far Is Too Far? – A Statistical Approach to Context‐contingent Proximity Modeling

Proximity is a fundamental concept in any comprehensive ontology of space ( Worboys 2001 ). The provision of a context‐contingent translation mechanism between linguistic proximity measures (e.g. “near”, “far”) and metric distance measures is an important topic in current GIS research. After a discussion of context factors that mediate the relationship between linguistic and metric distance measures, we present a statistical approach, Ordered Logit Regression, to the context‐contingent proximity modeling. The approach can predict proximity given the corresponding metric distance and context variables. An empirical case study with human subjects is carried out using this statistical approach. Interpretation and predictive accuracy of the empirical case study are discussed.     

紫外线模式预报方法的研究和试验

文章介绍了在T106全球谱模式中应用大气辐射传输模式预报紫外线辐射(UVR)的方法,给出了试验运行的结果.UVR强度的划分考虑了到达地表的UVR通量.参考国内、外紫外线(UV)预报服务的经验,制定了5个日光暴露的级别、相应的紫外线指数(UVI)及防护措施.1999年9月起,国家气象中心已在NOTES网上每月不定期地展示UVR预报的一些结果,2000年9月起,在Cray-C92业务操作系统上实施了连续的试验运行.     

Utilization of water resources,ecological balance and land desertification in the Tarim Basin,Xinjiang

Because of the human exploitation and utilization of water resources in the Tarim Basin, the water resources consumption has changed from mainly natural ecosystem to artificial oasis ecosystem, and the environment has changed correspondingly. The basic changes are: desertification and oasis development coexist, both “the human being advance and the desert retreat” and “the desert advance and the human being retreat” coexist, but the latter is dominant. In the upper reaches, water volume drawing to irrigated agricultural areas has increased, artificial oases have been enlarging and moving from the deltas in the lower reaches of many rivers to the piedmont plains. In the middle and lower reaches of the Tarim River, the stream flow has decreased, old oases have declined, natural vegetations have been degenerating, desertification has been enlarging, and the environment has deteriorated. The transition regions, which consist of forestlands, grasslands and waters between the desert and the oases, have been decreasing continuously, their shelter function to the oases has been weakened, and the desert is threatening the oases seriously.     

国际地磁学与高空物理学协会和国际地震学与地球内部物理学协会联合科学大会及地震电磁研究进展

简要介绍了 2 0 0 1年 8月 1 9～ 3 1日在越南河内召开的国际地磁学与高空物理学协会 ( IAGA)和国际地震学与地球内部物理学协会 ( IASPEI)联合科学大会以及地震电磁研究进展 ,表明地震电磁前兆在地震预测研究中具有一定的实际效果与良好的研究前景。我们建议在不久的将来能在北京举办 IAGA,IASPEI和 IUGG(国际大地测量学与地球物理学联合会 )大会。这将促进我国的科技进步 ,有助于加强我国在国际科学界的地位与影响。     

Application of Dangerous Probability Function in Risk Estimation of Surface Rupture Earthquake：Taking the Lingwu Fault in Ningxi1 Region as on Example

Based on the fitting on paleoearthquake data of intra-plate regions in the northern part of Chi-na and giving a statistical model of time interdependence,the potential damage earthquakes in a definite future period and characteristics of present shocks along the Lingwu fault have been analyzed by using dangerous probability function and some new data concerned.We have in-ferred that the fault has entered a period that earthquakes will probably occur.There exists a potential danger that a strong earthquake with Ms7.0-7.5 will occur in 10-100a.     

Quantitative reconstruction of the lake water paleotemperature of Daihai Lake, Inner Mongolia, China and its significance in paleoclimate

By measuring Sr/Ca ratios of the ostracod shells (Limnocthere cf. inopinata) in sediments of the Daihai Lake, and combined with Sr²⁺/Ca²⁺ ratios of the lake water, this paper obtained paleosalinity of the lake water. Vaporizing experiment of the lake water in laboratory showed that there was a quantitative relationship between salinity and oxygen isotope. Using this relationship, oxygen isotope values of the paleo-lake water were calculated. By measuring the oxygen isotope of the authigenic carbonate in the lake’s sediments, and in combination with the oxygen isotope values of the paleo-lake water, the paleotemperature of the lake water was calculated. Finally, based on these proxies, the paleoclimate in the lake basin was explored.