双树复小波变换在时移微重力监测上的应用——以辽河油田SAGD区为例     

蔡贇  王真理  梁瑶  张舒扬  陈桂廷  刘净余 《地球物理学进展》2021,36(2):549-558

SAGD开发会引起地下介质密度产生较大的变化,进而引起地表重力值的变化.时移微重力监测技术通过测量地表重力值的变化来监测SAGD开发过程中蒸汽腔的形态变化,从而获得油藏开发动态变化信息.针对微重力监测技术的重力异常提取对于描述储层变化至关重要.本文利用双树复小波变换将微重力数据分解为不同尺度小波系数,结合软硬阈值折中法...  相似文献   

NURE航空计划回顾与新时代航空γ能谱勘查启示     

李敬敏  米耀辉  骆遥 《物探与化探》2021,(2):394-402

国家铀资源评价(NURE)计划实现了覆盖美国本土和阿拉斯加的1:250000 NTMS图幅航空γ能谱测量和航磁测量,通过简要回顾该计划历程,重点针对NURE中航空地球物理勘查(航空y能谱和航磁测量),讨论了航空地球物理勘查中测量技术、数据处理及解释方法等.NURE航空测量在铀矿勘查和辐射环境评价、洲际航空地球物理编图等...  相似文献   

Quantitative analysis of riverbank groundwater flow for the Qinhuai River,China, and its influence factors          下载免费PDF全文

Chengpeng Lu  Shuai Chen  Yong Jiang  Junchao Shi  Congcong Yao  Xiaoru Su 《水文研究》2018,32(17):2734-2747

Interactions of surface water and groundwater (SW–GW) play an important role in the physical, chemical, and ecological processes of riparian zones. The main objective of this study was to describe the two‐dimensional characteristics of riverbank SW–GW interactions and to quantify their influence factors. The SW–GW exchange fluxes for six sections (S1 to S6) of the Qinhuai River, China, were estimated using a heat tracing method, and field hydrogeological and thermodynamic parameters were obtained via inverse modelling. Global sensitivity analysis was performed to compare the effects of layered heterogeneity of hydraulic conductivity and river stage variation on SW–GW exchange. Under the condition of varied river stage, only the lateral exchange fluxes at S1 apparently decreased during the monitoring period, probably resulting from its relatively higher hydraulic conductivity. Meanwhile, the SW–GW exchanges for the other five sections were quite stable over time. The lateral exchange fluxes were higher than the vertical ones. The riverbank groundwater flow showed different spatial variation characteristics for the six sections, but most of the higher exchange fluxes occurred in the lower area of a section. The section with larger hydraulic conductivity has an apparent dynamic response to surface water and groundwater level differences, whereas lower permeabilities severely reduced the response of groundwater flow. The influence of boundary conditions on SW–GW interactions was restricted to a limited extent, and the impact extent will expand with the increase of peak water level and hydraulic conductivity. The SW–GW head difference was the main influence factors in SW–GW interactions, and the influence of both SW–GW head difference and hydraulic conductivity decreased with an increase of the distance from the surface water boundary. For each layer of riverbank sediment, its hydraulic conductivity had greater influence on its groundwater flow than the other layers, whereas it had negligible effects on its overlying/underlying layers. Consequently, the variations in river stage and hydraulic conductivity were the main factors influencing the spatial and temporal characteristics of riverbank groundwater flow, respectively.  相似文献   

Radio observations of the OH line in Comet Halley     

Luo Xian-han  Zhou Ti-jian  Yao De-yi

Du Sheng-fu

Qian Zhi-han  Ji De-sheng  Zhang Wei-min 《Chinese Astronomy and Astrophysics》1988,12(4):324-327

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张强凹陷长北背斜生油岩有机地球化学特征     

商出岫  姚丹姝  王瑞璞 《国土资源》1996,(4)

张强凹陷长北背斜侏罗系上统有沙海组和九佛堂组两套生油合系，其有机质丰度属中等，沙海组生油岩多为腐泥腐殖型．地球化学分析表明，沙海组下段的生油岩处于低熟—成熟阶段，该地区各层原油主要来源于侏罗系上统沙海组下段生油岩．  相似文献   

DZW型微伽重力仪弹性系统的设计     

姚植桂 《大地测量与地球动力学》1996,(2)

论述了ＤＺＷ型微伽重力仪弹性系统中有关参数的计算以及弹簧材料的选择、加工与处理。  相似文献   

断层相互作用的初步讨论     

姚兰予  聂永安  赵根模 《大地测量与地球动力学》1996,(4)

给出了半无限介质中任意倾角的多个已发震矩形断层对邻近任意倾角的潜在活断层共同作用的合应力的解析表达式，从而可以计算震后合应力的调整值，为判断潜在活断层的稳定性提供依据。合应力Ｓｒ中既包括了作用在断层面上的正应力，又包括了断层面上的剪应力，它比单独用一个应力描述应力场更有效。最后，用１９７３年２月６日炉霍地震后的实际震例说明了地震断层错动对周围孕震区的触发作用  相似文献   

近50年湖南省雷暴气候特征分析     

周明薇  万协成  唐瑶  聂新宇 《南京气象学院学报》2018,10(4):507-513

根据湖南省74个地面气象站1961-2010年的雷暴日资料,利用数理统计、小波分析及Mann-Kendall检验等方法,对近50年雷暴气候特征进行分析.结果表明：1）湖南省雷暴日数空间分布特征为南部多、北部少,最大值出现在南部山地（65.38 d/a）,最小值出现在北部平原（21.92 d/a）,月平均雷暴日呈单峰值分布,3-9月为雷暴高发期;2）湖南省年平均雷暴日数存在8、16、24和30 a的周期变化规律,其中8 a周期振荡最显著;3）多雷期和少雷期的差异主要表现在副热带高压西伸脊点的位置以及青藏高原短波槽的位置和强弱上.  相似文献   

Spatiotemporal variations of potential evapotranspiration and aridity index in relation to influencing factors over Southwest China during 1960–2013     

Yifei?Zhao  Xinqing?ZouEmail author  Liguo?Cao  Yulong?Yao  Guanghe?Fu 《Theoretical and Applied Climatology》2018,133(3-4):711-726

This study investigated the spatial–temporal patterns and trends of potential evapotranspiration (ET₀) and aridity index (AI) over Southwest China during 1960–2013 based on daily temperature, precipitation, wind speed, sunshine duration, total solar radiation, and relative humidity data from 108 meteorological stations. The Penman–Monteith model, Mann–Kendall (M–K) test, moving t test, and Morlet wavelet method were used. The results indicated that ET₀ and AI across the region displayed decreasing trends, but the former was significant. After 2000, regionally average trends in ET₀ and AI increased rapidly, indicating that droughts increased over Southwest China in recent years. Spatially, the changes of ET₀ and AI were dissimilar and not clustered, either. Temporally, both ET₀ and AI displayed obvious abrupt change points over different timescales and that of AI was during the winter monsoon period. Significant periodic variations with periods of 27, 13, and 5 years were found in ET₀, but only of 13 and 5 years existed in AI. Correlation analysis revealed that the sunshine duration and wind speed were the dominant factors affecting ET₀ and that AI showed strong negative correlation with precipitation. The findings of this study enhance the understanding of the relationship between climate change and drought in Southwest China, while the mechanism controlling the variation in drought requires further study.  相似文献   

不同类型和强度的厄尔尼诺事件对次年华南前汛期降水的可能影响     

伍红雨  吴遥 《大气科学》2018,42(5):1081-1095

根据气象行业标准（QT/T370-2017）对厄尔尼诺事件不同类型的划分结果以及国家气候中心最新颁布的华南前汛期业务监测标准,利用1961~2016年NCEP/NCAR日、月尺度再分析大气环流资料、海表温度资料（ERSST V4）以及华南261个国家气象观测站逐日降水资料,采用相关、合成等方法分析了不同类型、强度的厄尔尼诺事件特征以及与次年华南前汛期的关系,并探讨其海温和大气环流异常特征。结果表明,厄尔尼诺事件的类型、强度对次年华南前汛期降水的影响存在明显差异。中等及以上强度东部型厄尔尼诺事件次年,华南前汛期开汛早、结束晚,前汛期持续时间长、降水多;弱等级的东部型以及中部型厄尔尼诺事件次年则相反。在厄尔尼诺事件次年华南前汛期,中等及以上强度东部型厄尔尼诺相对弱东部型或中部型厄尔尼诺的大气环流存在明显差异。高层西风急流明显加强,中层北半球极涡加强,东亚大槽强,低层菲律宾以东存在反气旋异常环流,华南存在南北风的交汇和水汽辐合加强,有利于华南前汛期降水偏多。  相似文献