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991.
LBM钻井液是一种低粘度低失水量的高效造浆材料,通过在绳索取心中应用,证明了LBM钻井液具有良好的抑制水敏性地层膨胀与分散的能力.可有效防止粘附卡钻事故及解决钻杆内壁结垢问题.是绳索取心钻进较理想的钻井液材料。 相似文献
992.
鄂尔多斯盆地西峰油田白马南特低渗岩性油藏储层地质建模 总被引:2,自引:0,他引:2
以鄂尔多斯盆地西峰油田白马南长81砂岩油藏为例,应用随机序贯高斯模拟法(SUS)和序贯指示模拟法(SIS)建立研究目标的储层地质模型,进而探讨了在特低渗岩性油藏中相对高渗透储层形成的控制因素。认为长81油藏储层的形成主要受控于沉积作用;成岩作用对改善储层物性及油气的运聚起了重要的作用。砂体的三维模拟结果显示主砂体位于研究区西部,呈西南-东北向展布。储层物性参数的三维模拟也表明优质储层主要分布在主砂体带上长石溶蚀相和绿泥石薄膜胶结成岩相区。 相似文献
993.
994.
以江西省丹霞地貌景观为研究对象,介绍了遥感和地理信息系统技术在丹霞地貌景观旅游资源调查中应用的原理和方法;根据已知丹霞地貌景观的遥感影像、地质背景、三维地形模型、地形坡度等多元信息特征,总结了丹霞地貌景观的解译标志;利用这些解译标志对江西省丹霞地貌景观进行详细解译。结果表明,江西省有丹霞地貌景观123处,其中新发现的有78处。为江西省的旅游发展规划和丹霞地貌景观旅游资源的开发评价提供了重要依据。 相似文献
995.
在实际低应变基桩动测资料解释工作中常发生误判,其原因除测试人员素质的主观因素外,客观上存在反演问题多解性亦是重要原因之一。这里从正演理论计算与物理概念上阐明,在一定桩土系统的物性、几何参数与拟合精度条件下,反演问题多解性是客观存在的。并且进一步探讨了进行人工拟合时应遵守的规则,正确运用此规则能尽量避免误判的产生。在此规则指导下,对易发生误判的实测曲线进行人工拟合,进一步说明了反演多解性问题的客观存在。 相似文献
996.
The Chinese Loess Plateau is suffering from severe soil erosion. The eco-environmental changes of the plateau are believed
to have an important influence on global eco-environmental sustainability; hence, this problem has attracted considerable
attention from scientists around the world. This study has two purposes; application of remote sensing (RS) and geographic
information system (GIS) techniques in the dynamic analysis of eco-environmental changes in the semiarid zone; and using the
Longdong region of the Chinese Loess Plateau as an example, to make dynamic analysis of the eco-environmental changes of the
region during the 1986–2004 period and identify controlling factors. Landsat Thematic Mapper (TM) data at a spatial resolution
of 30 m were used for analysis. Two training areas were selected in Jingning and Qingcheng counties for analysis using 10-m
resolution SPOT and Landsat TM data. The satellite RS images were obtained from the Institute of Remote Sensing Application
(IRSA), Chinese Academy of Sciences (CAS). Each images was rectified by Albers Equal Area Conic projection based on 1:50,000
scale topographic maps after spectrum preparation of the images. To make the precision within 1 or 2 pixels, the accurate
coordinative control points of the two systems were identified. Then the interpretation key was established based on the land
use/cover survey in the study area. The images were classified into six primary environmental types (farmland, forest, grassland,
water, construction area, and desert) and 25 sub-types using a visual image interactive interpretation method to obtain vector
and attribute data. The resultant accuracy of the land use/cover classification reached 95%. Finally, the transformation areas
and ratios of various eco-environmental types in the region were calculated to obtain the transition matrixes of eco-environmental
types in the two training areas, Jingning and Qingcheng. This study demonstrates that satellite RS and GIS techniques are
effective tools to monitor and analyze the eco-environmental changes in the semiarid region. Visual image interactive interpretation
based on GIS technique provides comprehensive information on the direction, rate, and location of eco-environmental changes.
The transition matrix model can be used to precisely analyze the variation and rates of the eco-environmental types and their
spatial distribution. Great land use changes have taken place Longdong during the 1986–2004 period. These eco-environmental
changes were driven by natural and human factors. Natural factors influencing the Longdong region of the Chinese Loess Plateau
mainly include temperature, water condition, terrain, soil, and erosion; while human activities include over-cultivation,
overgrazing, and fuelwood cutting. As viewed from the extent and severity of the influences, human activities play a very
important role in altering the eco-environment of the semiarid region. The study results indicate a need for future research
and observation in the semiarid region. 相似文献
997.
Outgoing long wave radiation variability from IR satellite data prior to major earthquakes 总被引:12,自引:1,他引:12
Dimitar Ouzounov Defu Liu Kang Chunli Guido Cervone Menas Kafatos Patrick Taylor 《Tectonophysics》2007,431(1-4):211
Our analysis of the continuous outgoing long wave earth radiation (OLR) indicates anomalous variations prior to a number of medium to large earthquakes. The most recent analysis of OLR is from the M9.0 Sumatra Andaman Islands mega trust event. We compared the reference fields for December 2001 to 2004 and found OLR anomalous values, > 80 W/m2, (2σ) within the epicentral area on Dec 21, 2004, 5 days before the event. We used the NOAA/IR daily (one degree) and monthly (two and half degree) gridded data to differentiate between the global and seasonal variability and the transient local anomalies. The cause of such anomalies is not fully understood; one possible explanation is the existence of thermal outgoing radiation as a result of near ground air ionization and latent heat change due to change of air humidity and temperature. This phenomenon is hypothesized to be part of a relationship between tectonic stresses, electrochemical and thermodynamic processes in the atmosphere and increasing mid IR flux, all part of a family of electromagnetic (EM) phenomena related to earthquake activity. The time scale of the observed variations is a few weeks before the onset of the seismic event. In comparison with several years of data, the observed time-series preceding the earthquake had unusually high OLR. The OLR anomaly corresponds to a large area of ground coverage and coincides with the main epicentral zone. The significance of these observations is explored using data from most recent East Asian earthquake swarm of December 2004 and three other earthquakes. 相似文献
998.
Graciela Salinas de Salmuni Inés Velasco Mirta Fresina Alberto L. Flores 《GeoJournal》2007,70(4):273-279
Much of the central-western region of Argentina, where San Juan Province is located, experiences arid to semi-arid climatic
conditions with low average annual rainfall accompanied by substantial evapotranspiration. Consequently, a viable crop industry
depends to a large extent upon irrigation from major river systems. Increasing demand for water in the lower basin of the
San Juan River is emphasizing the need for more accurate estimates of water used for irrigation. Since the water demand for
a particular crop is very closely related to crop area, monitoring the area of crop under irrigation is considered a proxy
for the amount of water used. Landsat 5 imagery for the growing season, field data and aerial photographs were used to evaluate
crop area. 相似文献
999.
The coastal dunes of Israel have been undergoing a process of stabilization since 1948. One of the major features of this process is a change in the surface properties of the dunes – the development of a biological soil crust (BSC), and a change in the properties of the sand grains themselves. In Ashdod, at the southern coastal plain of Israel, sand properties that include the BSC, their fines (silt and clay) content and free iron-oxide (indicating their degree of rubification) have been analysed in detail using field and lab spectroscopy methods. In addition, sand erosion and deposition were measured using erosion pins to determine their effect on the presence of the above-mentioned factors. It was found that the BSC over these dunes is comprised of green algae that differs in its reflectance spectra from cyanobacterial crust, especially in the blue band. The crust was found to be particularly developed in the stable areas (mainly the interdunes) and on the north-facing slopes rather than on the south-facing slopes. A positive correlation was found between the crust fines and chlorophyll content, with stable areas showing more developed BSC. The stable areas showed also a lower albedo and slightly more developed reddish colour, indicating a slightly higher rate of rubification. This study demonstrates that the intensity of sand erosion/deposition rates affects soil properties, with the BSC being the fastest to react to the stabilization process (months to several years), followed by the content of fine particles (several years to a decade), whereas the rubification process is a much weaker marker and may need much longer time periods to develop (decades to centuries). 相似文献
1000.
介绍了内陆湖泊水质遥感监测的特点及遥感监测水质的机理;总结了国内外近年来用于内陆湖泊水质参数反演的3种常用方法:经验模型、半经验法和机理模型法,并分析了3种模型的优缺点;讨论了目前遥感在水质监测应用中存在的问题和未来该领域研究的重点。 相似文献