应用“0”域概念进行对流云防雹(增雨)作业

人工防雹(增雨)作业所依据的原理是成雹(增雨)机制和雹云(积云)结构特征,而作业的难题是判断作业的部位和时机。利用冰雹存在成长“穴道”的新概念,对所获取的雷达基本反射率、反射率剖面(RCS)、速度剖面(VCS)及风廓线(VWP)等资料进行分析,找到相对水平风速为0的区域,即可准确判定“0”域的位置,找到冰雹成长的“穴道”,解决人工防雹(增雨)作业中作业部位和时机的判断问题,以此指导人工防雹(增雨)作业。     

大港枣园油田枣北孔店组砂岩储层微观非均质性与改善开发效果分析

砂岩储层的微观非均质性主要由砂岩孔隙特征、粘土矿物和孔喉分布等表征。通过岩心样品的常规薄片,铸体薄片、扫描电镜观察和粘土矿物X—衍射分析以及孔隙结构图象分析,揭示了大港枣园油田孔一段砂岩微观非均质性为中到强非均质储层,孔二段砂岩为强非均质储层,并建立了各层段的非均质模式,提供了相应的增产改造措施,使开发效果得到改善。     

Comparison of input data with different spatial resolution in landscape pattern analysis – A case study from northern Latvia

A suitable spatial scale needs to be selected in geographical and landscape ecological research, and this requires great consideration as different scales have profound effect on derived landscape spatial patterns. Numerous studies have investigated the effects of different scales on landscape metrics using simulated patterns, but few have been conducted to compare different data sources with variable scale for regional- and landscape-scale assessments. Possibly this has occurred because researchers have been prone to use the best available source, a well-known standard, and easiest to use. This study was conducted to assess the impact of input data resolution on values of landscape pattern metrics in four landscapes at scales 1:10 000, 1:50 000 and 1:100 000. The aim was to determine the applicability of three data sources for thematic models in landscape pattern analyses in the Eastern Baltic region. We found that the utility of CORINE Land Cover data for comprehensive structural assessment in mosaic-type landscapes was very limited, as the level of cartographic generalization excluded many small and linear landscape structure elements with potentially high importance for landscape functioning, such as habitat continuity. We also found that actual area harvested using clearcuts was considerably higher than shown in CORINE data, due to clearcuts size being much smaller than the minimum mapping unit. In the light of this, we suggest using data with spatial resolution corresponding to a cartographic scale of at least 1:50 000, in cases when spatial patches have size up to 25 ha.     

Two‐phase dynamic analysis by material point method

This paper extends the material point method to analyze coupled dynamic, two‐phase boundary‐valued problems via a velocity formulation, in which solid and fluid phase velocities are the variables. Key components of the proposed approach are the adoption of Verruijt's sequence of update steps when integrating over time and the enhancement of volumetric strains. The connection between fractional step method and the time‐stepping algorithm presented in this paper is addressed. Enhancement of volumetric strains allows lower order variations in pressure and mitigates spurious pressure fields and locking that plague low‐order finite‐element implementations. A stress averaging technique to smoothen stress variations is proposed, and the local damping procedure adopted by FLAC is extended to handle two‐phase problems. Special Kelvin‐Voigt boundaries are developed to suppress reflections at artificial boundaries. Idealized examples are presented to demonstrate the capability of the proposed framework to accurately capture the physics of wave propagation, consolidation and wave attack on a sea dike. Copyright © 2012 John Wiley & Sons, Ltd.     

2014—2022年古田人工增雨随机试验物理检验

基于2014—2022年福建古田地面火箭人工增雨随机试验样本, 利用回波强度、回波顶高和负温层厚度等雷达宏观参量以及双偏振参量差分反射率和差分相位差, 开展人工增雨随机试验物理检验及催化个例的物理响应研究。结果表明:与作业后非催化样本回波强度小幅上升后快速减弱相比, 81.6%的催化样本在作业后回波强度增强, 其中52.6%的样本最大增幅为0~20%(不含0), 21.1%的样本增幅为20%~50%(不含20%), 7.9%的样本增幅超过50%;作业后52.6%的催化样本出现回波顶高升高和负温层增厚现象, 其中36.8%的样本增长0~20%(不含0), 13.2%的样本增长20%~50%(不含20%), 2.6%的样本增长超过50%;催化样本的双偏振参量差分反射率和差分相位差在作业后也出现持续增强;个例分析显示, 催化作业有助于云体发展、增强和维持, 促使降水量显著增加, 不仅降水粒子增多增大, 云体生命史也延长。     

Comparison of Satellite Altimetric Gravity and Global Geopotential Models with Shipborne Gravity in the Red Sea

The determination of high-resolution geoid for marine regions requires the integration of gravity data provided by different sources, e.g. global geopotential models, satellite altimetry, and shipborne gravimetric observations. Shipborne gravity data, acquired over a long time, comprises the short-wavelengths gravitation signal. This paper aims to produce a consistent gravity field over the Red Sea region to be used for geoid modelling. Both, the leave-one-out cross-validation and Kriging prediction techniques were chosen to ensure that the observed shipborne gravity data are consistent as well as free of gross-errors. A confidence level equivalent to 95.4% was decided to filter the observed shipborne data, while the cross-validation algorithm was repeatedly applied until the standard deviation of the residuals between the observed and estimated values are less than 1.5 mGal, which led to the elimination of about 17.7% of the shipborne gravity dataset. A comparison between the shipborne gravity data with DTU13 and SSv23.1 satellite altimetry-derived gravity models is done and reported. The corresponding results revealed that altimetry models almost have identical data content when compared one another, where the DTU13 gave better results with a mean and standard deviation of ?2.40 and 8.71 mGal, respectively. A statistical comparison has been made between different global geopotential models (GGMs) and shipborne gravity data. The Spectral Enhancement Method was applied to overcome the existing spectral gap between the GGMs and shipborne gravity data. EGM2008 manifested the best results with differences characterised with a mean of 1.35 mGal and a standard deviation of 11.11 mGal. Finally, the least-squares collocation (LSC) was implemented to combine the shipborne gravity data with DTU13 in order to create a unique and consistent gravity field over the Red Sea with no data voids. The combined data were independently tested using a total number of 95 randomly chosen shipborne gravity stations. The comparison between the extracted shipborne gravity data and DTU13 altimetry anomalies before and after applying the LSC revealed that a significant improvement is procurable from the combined dataset, in which the mean and standard deviation of the differences dropped from ?3.60 and 9.31 mGal to ?0.39 and 2.04 mGal, respectively.     

Image Filtering by Factorial Kriging—Sensitivity analysis and application to Gloria side-scan sonar images

Factorial Kriging (FK) is a data- dependent spatial filtering method that can be used to remove both independent and correlated noise on geological images as well as to enhance lineaments for subsequent geological interpretation. The spatial variability of signal, noise, and lineaments, characterized by a variogram model, have been used explicitly in calculating FK filter coefficients that are equivalent to the kriging weighting coefficients. This is in contrast to the conventional spatial filtering method by predefined, data-independent filters, such as Gaussian and Sobel filters. The geostatistically optimal FK filter coefficients, however, do not guarantee an optimal filtering effect, if filter geometry (size and shape) are not properly selected. The selection of filter geometry has been investigated by examining the sensitivity of the FK filter coefficients to changes in filter size as well as variogram characteristics, such as nugget effect, type, range of influence, and anisotropy. The efficiency of data-dependent FK filtering relative to data-independent spatial filters has been evaluated through simulated stochastic images by two examples. In the first example, both FK and data-independent filters are used to remove white noise in simulated images. FK filtering results in a less blurring effect than the data-independent fillers, even for a filter size as large as 9 × 9. In the second example, FK and data-independent filters are compared relative to the extraction of lineaments and components showing anisotropic variability. It was determined that square windows of the filter mask are effective only for removing Isotropie components or white noise. A nonsquare windows must be used if anisotropic components are to be filtered out. FK filtering for lineament enhancement is shown to be resistant to image noise, whereas data-independent filters are sensitive to the presence of noise. We also have applied the FK filtering to the GLORIA side-scan sonar image from the Gulf of Mexico, illustrating that FK is superior to the data-independent filters in removing noise and enhancing lineaments. The case study also demonstrate that variogram analysis and FK filtering can be used for large images if a spectral analysis and optimal filter design in the frequency domain is prohibitive because of a large memory requirement.     

低渗卤水盆地提高CO2注入性的技术方法: 以江汉盆地为例

注入性是关系CO₂地质储存成功与否的一个关键的技术和经济问题, 评价与提高CO₂在中国陆相沉积盆地普遍存在的低渗储层中的注入能力对于碳捕集与封存技术在中国的应用与推广具有重要意义.以江汉盆地江陵凹陷为例, 通过数值模拟的方法开展高盐低渗储层CO₂注入能力评估与提高方案研究.结果表明: 预注入淡水和低盐度的微咸水溶液均可不同程度地缓解注入井周围的盐沉淀问题; 预注入CO₂饱和溶液或稀盐酸溶液, 可显著提高注入井周围的孔渗值, 提高CO₂注入性, 但由于储层本身的低渗性, 迁移距离有限, 短时间内较难实现CO₂注入速率的大幅度提高.采取水力压裂措施可显著提高低渗储层中CO₂的注入性, 其提升能力取决于压裂裂缝的半长度以及压裂程度.对于单个垂直井, 通过水力压裂对储层加以改造, 并采取多层注入的方式, 在低渗储层中实现数十万吨的年注入量是可能的.      

人工增雨效果的数值统计评估方法

利用1995～2001年河南省春季降水资料，采用数值预报与统计相结合的方法，对飞机人工增雨的效果进行检验。该方法的基本思路是根据降水的气候特征设定增雨效果的评估区，在同一评估区内应用数值模式MM5V3对历史降水过程的降水量进行数值预报，从而获得一组预报雨量，对非增雨过程的数值预报雨量与降水实况进行统计分析，建立预报雨量与实况雨量的数理统计关系。对增雨作业过程的降水同样采用相同的数值模式进行预测，并与增雨后的实况雨量比较，从而得到飞机人工增雨效果。评估结果表明：1995～2001年春季飞机人工增雨效果比较明显，豫北区(Ⅰ区)平均为16．7％，豫东区(Ⅱ区)平均为19．3％。     

多普勒雷达在对流云火箭增雨作业中的应用

介绍了多普勒雷达速度PPI产品图像定性识别方法,分析了与对流性降水云体有关的图像特征:①冷暖平流与大尺度辐合辐散运动相结合的零速度线;②风向性辐合辐散与风速性辐合辐散引起的正、负速度面积的不对称及正、负速度数值的差异;③较强对流单体显示的中小尺度的辐合、辐散、逆风区等。结合火箭人工增雨作业指标,给出了由雷达产品确定作业最佳时机和最佳部位的方法:辐合发展期为作业最佳时机,辐合最强区域为作业最佳部位,并由此定量计算出火箭发射的方位角、仰角;由垂直累积液态含水量和回波顶高度产品定量计算出作业区的体积,进而求得作业所需用弹量。