基于特征分析法的琼南矽卡岩型矿床成矿预测研究     

吴传军  许德如  周迎春  候茂洲  于亮亮  胡国成 《大地构造与成矿学》2015,(3)

在系统总结琼南矽卡岩型矿床区域成矿地质背景与成矿规律的基础上,分析和提取了地质、物探、化探、重砂、遥感等多元有利找矿信息,具体包括碳酸盐岩地层、燕山晚期中酸性侵入岩、控矿断裂、航磁推断磁性蚀变带、化探Cu、Pb、Zn、Au、Ag单元素异常及Cu-W-Mo、Pb-Zn、Au-Ag组合元素异常、自然重砂Fe、Pb-Zn异常以及遥感羟基和铁染蚀变异常等。并利用上述找矿信息及6个模型控制单元(即已知含矿单元)建立了特征分析初始矿化模型M1,同时为解决模型M1中控制单元不足的问题,我们从中筛选了联系度f≥4的26个单元作为新的模型控制单元,重新建立了广义矿化模型M2,并据此圈定了4个A级、2个B和2个C级矽卡岩型矿床找矿预测靶区,为本区矽卡岩型矿床的找寻提供了重要的科学依据。  相似文献   

武汉地区梅雨期暴雨预报方法初探          下载免费PDF全文

徐迎春  刘立  庞晶 《气象与减灾研究》2017,40(3):231-235

使用地面降水观测资料和高空探测资料,运用线性倾向估计法和相关性分析法,分析了2000—2012年武汉地区梅雨期(6—7月)暴雨的气候特征,并建立了暴雨天气预报方程。结果表明,6—7月武汉地区各旬暴雨日数呈先升后降趋势,其中最大值出现在6月下旬;暴雨集中期为6月下旬—7月中旬,占梅雨期总暴雨日数的61%;暴雨局地性强,雨强呈上升趋势。筛选出武汉站强天气威胁指数、百色站850 hPa层的露点温度和怀化站850 hPa层的风向、风速作为预报因子,建立武汉地区梅雨期暴雨预报方程,实际预报效果检验结果表明该方程的预报质量优于实际业务中常用的数值预报产品。  相似文献   

Changes in Wind Speed and Extremes in Beijing during 1960--2008 Based on Homogenized Observations   总被引：3，自引：0，他引：3  

LI Zhen  YAN Zhongwei  TU Kai  LIU Weidong  WANG Yingchun 《大气科学进展》2011,28(2):408-420

Daily observations of wind speed at 12 stations in the Greater Beijing Area during 1960–2008 were homogenized using the Multiple Analysis of Series for Homogenization method. The linear trends in the regional mean annual and seasonal (winter, spring, summer and autumn) wind speed series were-0.26,-0.39,-0.30,-0.12 and-0.22 m s-1 (10 yr)-1 , respectively. Winter showed the greatest magnitude in declining wind speed, followed by spring, autumn and summer. The annual and seasonal frequencies of wind speed extremes (days) also decreased, more prominently for winter than for the other seasons. The declining trends in wind speed and extremes were formed mainly by some rapid declines during the 1970s and 1980s. The maximum declining trend in wind speed occurred at Chaoyang (CY), a station within the central business district (CBD) of Beijing with the highest level of urbanization. The declining trends were in general smaller in magnitude away from the city center, except for the winter case in which the maximum declining trend shifted northeastward to rural Miyun (MY). The influence of urbanization on the annual wind speed was estimated to be about-0.05 m s-1 (10 yr)-1 during 1960–2008, accounting for around one fifth of the regional mean declining trend. The annual and seasonal geostrophic wind speeds around Beijing, based on daily mean sea level pressure (MSLP) from the ERA-40 reanalysis dataset, also exhibited decreasing trends, coincident with the results from site observations. A comparative analysis of the MSLP fields between 1966–1975 and 1992–2001 suggested that the influences of both the winter and summer monsoons on Beijing were weaker in the more recent of the two decades. It is suggested that the bulk of wind in Beijing is influenced considerably by urbanization, while changes in strong winds or wind speed extremes are prone to large-scale climate change in the region.  相似文献   

基于雷达资料4DVar的低层热动力反演系统及其在北京奥运期间的初步应用分析   总被引：13，自引：5，他引：8  

陈明轩  王迎春  高峰  王婷婷 《气象学报》2011,69(1):64-78

在变分多普勒雷达分析系统(VDRAS)中,通过对雷达资料的质量控制和预处理、云尺度模式的暖雨参数化方案、中尺度初猜场的插值分析方法、循环同化的冷启动和热启动中尺度背景场的计算方案等进行改进,实现了VDRAS对低层动力和热力场的分析反演及其在北京奥运期间的实时应用.改进后的VDRAS利用四维变分(4DVar)同化技术和一...  相似文献   

Estimating the number of casualties in earthquakes from early field reports and improving the estimate with time     

Yingchun Li  Zhongliang Wu  Yizhe Zhao 《Natural Hazards》2011,56(3):699-708

We investigate the time dependence of the number of deaths reported through Internet after earthquakes and/or earthquake-generated tsunami. An approximate relation N(t) = N ₀ [1 − exp(−αt)] is used to describe such temporal variation, in which N(t) is the number of deaths reported at time t, N ₀ is the final number of deaths, and α is the coefficient reflecting the rescue process. We considered 12 earthquake cases since 2001 using the information from the web, which shows that the N-t relation approximates the data, and the logarithm of α is reversely proportional to the magnitude of earthquake, albeit with significant uncertainties. Quick and rough estimate of the final death toll can be made using this simple and approximate relation, with the empirical α-M relation as a reference. For the 12 cases under consideration, quick and rough estimate of fatalities can be obtained 2 days after the earthquake, fitting the real situation in the order of magnitudes. Although being very rough, this estimate can assist the emergency decision-making and can be revised as time lapses. When more and more data becomes available, curve fitting can provide both N ₀ and α at the same time. The method is tested against the data of the recent Yushu earthquake on April 14, 2010.  相似文献   

北京“7.21”暴雨雨团的发生和传播机理   总被引：6，自引：2，他引：4  

陈明轩  王迎春  肖现  高峰 《气象学报》2013,71(4):569-592

基于京津冀5部新一代天气雷达、区域5min自动站和中尺度数值模式模拟资料,通过雷达资料快速更新循环四维变分同化技术和三维数值云模式对低层三维动力和热动力特征的模拟分析,为北京"7.21"特大暴雨中尺度对流系统(Mesoscale Convective System,MCS)的结构特征和传播机理的分析提供了佐证。结果表明:(1)低层动力场和地形强迫对MCS的触发、增强和维持起到关键作用。在MCS形成阶段,地形强迫有利于低空偏南气流带来的暖湿空气在山前的辐合上升。随着MCS的加强,强降水区域呈现与地形走向接近的"西南—东北"向带状分布,单体移动具有明显的"列车效应",而MCS整体则向东偏南缓慢传播。在MCS传播前沿(山前)形成强的出流风场,低层2 km以下均为深厚的辐合上升区且进一步加强,表明地形强迫和低层风辐合对偏南暖湿空气抬升起到重要作用,有利于MCS长时间"列车效应"的维持和MCS的发展。MCS出流风场与平原地区近地面偏南风交汇,使得在距MCS传播前沿约50 km的、已经存在的一个接近"西西南—东东北"走向的出流边界明显增强。在MCS传播前沿存在较为明显的0-3 km风垂直切变,由MCS出流与低层偏南风形成的风向切变以及地形强迫造成的风速切变构成,切变区域与地形走向及MCS伸展方向密切相关,切变强度达到中纬度低层强切变阈值范围。低层风垂直切变与MCS存在明显的正反馈效应,亦有利于MCS的长时间发展和维持。(2)低层热动力场为MCS的发展、传播提供了重要条件。在MCS传播前方的环境低层是明显的暖湿区,而在传播后方的低层则是由于地面冷锋及MCS降水造成的冷区,冷暖空气交汇对MCS的高度组织化和强降水的持续起到重要作用。低层的热力层结不稳定区域主要分布在MCS的南部到西南部地区,为MCS尾部风暴单体的不断新生和移动传播创造了良好的热力条件。最后,通过观测和模拟结果综合分析,初步得出了与此次强降水MCS发展演变密切相关的低层热、动力配置的概念模型,为MCS"列车效应"和后向传播特征的机制分析提供了依据。  相似文献   

近50a石河子棉区≥10℃积温时空变化特征     

胡启瑞  王森  李迎春  吉春容 《沙漠与绿洲气象(新疆气象)》2022,16(6):146-151

利用石河子棉区4个气象站1971-2020年的逐日气象资料,采用气候倾向率、累计距平、均方差、Mann-Kendall突变检验等方法,分析了石河子棉区10℃积温的时空变化特征。结果表明;石河子棉区各地及全区≥10℃初日呈显著提前趋势,≥10℃终日略微推迟,≥10℃持续日数显著延长,≥10℃积温明显增多。≥10℃积温及持续日数均在1964年发生了由少到多的突变,≥10℃积温主要在5-9月,7月为高峰值。≥10℃积温正常年份最多,概率超过64%,依次向两端递减。≥10℃积温偏低地区主要在莫索湾,≥10℃积温偏高地区主要在乌兰乌苏。阶段Ⅱ（1995-2020年）与阶段Ⅰ（1961-1994年）相比,≥10℃积温3500-3800℃·d明显减少,3800-4100℃·d明显增多。气候变化背景下,石河子棉区热量条件有较好的改善,棉花低温冷害会有所减轻,石河子棉区品中布局仍应以早熟或特早熟为主。  相似文献   

注浆工程扰动下煤系砂岩含水层水岩作用机理——以桃园煤矿为例     

郭艳  桂和荣  魏久传  倪建明  成荣发  庞迎春  张治  洪荒  胡满聪  崔亚利  梁展  李俊  陈家玉  李晨 《煤田地质与勘探》2021,49(1):232-240

煤系砂岩裂隙水是煤矿重要的充水水源之一,以淮北煤田桃园煤矿二叠纪煤系为研究对象,在分析该矿水害注浆治理以来煤系水水化学特征的基础上,阐明了地下水水文地球化学作用机理及其控制因素。结果表明:注浆治理期间,煤系水中主要阳离子为Na+,主要阴离子为SO₄2-;阳离子质量浓度由大到小为Na+、Ca2+、Mg2+,阴离子质量浓度由大到小为SO₄2-、HCO₃-、Cl-;通过Durov水化学图分析,注浆治理期间煤系水化学类型以Na-SO₄和Na-HCO₃为主;煤系水中存在黄铁矿氧化或碳酸盐、硫酸盐溶解作用,并伴随着一定程度的阳离子交换作用与脱硫酸作用,特别是在注浆治理工程实施期间,阳离子交换作用增强;大型突水、注浆治理防治水工程、地质构造背景及采矿活动等均不同程度地影响了煤系水水岩作用,且随注浆治理范围增大,影响程度增大。该研究成果对于煤矿涌（突）水水源识别及水害防治具有重要意义,为类似条件下的其他煤矿（区）在突水或注浆治理扰动下的地下水水文地球化学研究及应用提供参考。   相似文献   

南极横贯南极山脉休斯陡崖花岗质岩体的成因     

崔迎春  马立杰  刘晨光  王庆超  Andreas L&#;UFER 《地质力学学报》2021,27(5):783-795

为了探讨横贯南极山脉休斯陡崖花岗质岩体的岩石成因,对其开展了岩相学和岩石化学分析。结果表明,休斯陡崖岩体主体岩石为二长花岗岩,后期被细粒二长花岗岩岩脉侵入。二者都具有高硅、富碱和高钾特征,里特曼指数小于3,岩石铝饱和指数(A/CNK)值小于1;微量元素原始地幔标准化分布型式具有Rb、Th、U和K元素富集,Nb、Ta、Nd和Ti等元素亏损特征;稀土元素总量偏低,轻稀土富集。主期二长花岗岩的稀土元素球粒陨石标准化分布型式具有轻微的负Eu异常,而岩脉具有正的Eu异常。休斯陡崖岩体的岩石类型为钙碱性准铝质I型花岗岩,源区为下陆壳,并伴有幔源物质的混入。在源区,岩浆发生了不同程度的斜长石、钛铁矿、金红石和磷灰石的分离结晶作用,其形成的构造环境为与俯冲作用有关的火山岛弧环境。   相似文献   

A unified model for the formation and distribution of both conventional and unconventional hydrocarbon reservoirs     

Xiongqi Pang  Chengzao Jia  Junqing Chen  Maowen Li  Wenyang Wang  Qinhong Hu  Yingchun Guo  Zhangxin Chen  Junwen Peng  Keyu Liu  Keliu Wu 《地学前缘(英文版)》2021,12(2):695-711

The discovery and large-scale exploration of unconventional oil/gas resources since 1980s have been considered as the most important advancement in the history of petroleum geology;that has not only changed the balance of supply and demand in the global energy market,but also improved our understanding of the formation mechanisms and distribution characteristics of oil/gas reservoirs.However,what is the difference of conventional and unconventional resources and why they always related to each other in petroliferous basins is not clear.As the differences and correlations between unconventional and conventional resources are complex challenging issues and very critical for resources assessment and hydrocarbon exploration,this paper focused on studying the relationship of formations and distributions among different oil/gas reservoirs.Drilling results of 12,237 exploratory wells in 6 representative petroliferous basins of China and distribution characteristics for 52,926 oil/gas accumulations over the world were applied to clarify the formation conditions and genetic relations of different oil/gas reservoirs in a petroliferous basin,and then to establish a unified model to address the differences and correlations of conventional and unconventional reservoirs.In this model,conventional reservoirs formed in free hydrocarbon dynamic field with high porosity and permeability located above the boundary of hydrocarbon buoyancy-driven accumulation depth limit.Unconventional tight reservoirs formed in confined hydrocarbon dynamic field with low porosity and permeability located between hydrocarbon buoyancy-driven accumulation depth limit and hydrocarbon accumulation depth limit.Shale oil/gas reservoirs formed in the bound hydrocarbon dynamic field with low porosity and ultra-low permeability within the source rock layers.More than 75%of proved reserves around the world are discovered in the free hydrocarbon dynamic field,which is estimated to contain only 10%of originally generated hydrocarbons.Most of undiscovered resources distributed in the confined hydrocarbon dynamic field and the bound hydrocarbon dynamic field,which contains 90%of original generated hydrocarbons,implying a reasonable and promising area for future hydrocarbon explorations.The buried depths of hydrocarbon dynamic fields become shallow with the increase of heat flow,and the remaining oil/gas resources mainly exist in the deep area of“cold basin”with low geothermal gradient.Lithology changing in the hydrocarbon dynamic field causes local anomalies in the oil/gas dynamic mechanism,leading to the local formation of unconventional hydrocarbon reservoirs in the free hydrocarbon dynamic field or the occurrence of oil/gas enrichment sweet points with high porosity and permeability in the confined hydrocarbon dynamic field.The tectonic movements destroy the medium conditions and oil/gas components,which leads to the transformation of conventional oil/gas reservoirs formed in free hydrocarbon dynamic field to unconventional ones or unconventional ones formed in confined and bound hydrocarbon dynamic fields to conventional ones.  相似文献