闽江河口潮流数值模拟     

梁金焰 《台湾海峡》1997,16(1):1-9

应用边界拟合坐标系统，解决了闽江河口河道曲折汊道多造成的计算方向与河底走向交角过大的难点；针对闽江河口长宽比相差较大的特点，移植了通常用于河道计算的沿纵向求解大尺度矩阵问题转化为沿横向小尺度矩阵求逆的水流方程求解方法，采用全隐差分格式，使闽江口数模网格步长最小控制在50m左右，时步长达3min，潮位、流场与实测拟合良好。  相似文献   

区域性地质灾害气象预报方法研究   总被引：8，自引：5，他引：8  

薛建军  徐晶  张芳华  牛若芸  张金艳  杨元琴 《气象》2005,31(10):24-27

从气象的角度，基于对全国地质灾害预警区域的划分，利用历史地质灾害记录以及历史气象资料，分区建立了全国范围的区域气象潜势预报模型，并从2003年6月1日开始投入业务应用。总体预报服务效果较好，收到了较好的社会效益。同时还要进一步加强科学研究，提高科技含量，优化预报模型。  相似文献   

Modeling the relationship of land use change and some geophysical indicators for the interlock area of farming and pasturing in China     

DENG Xiangzheng  LIU Jiyuan  ZHUANG Dafang  ZHAN Jinyan  ZHAO Tao 《地理学报》2002,12(4):397-404

This paper discusses land-use changes in the interlock area of farming and pasturing (IAFP)in northern China. It presents detailed analyses of land-use features in the IAFP, which are controlled by the macro geomorphic units and geophysical conditions-constraints or advantages. Additionally, it selects some indicators, according to the availability in acquiring and processing their quantitative data, to analyze the canonical correlations between the typical conversion of grassland and geophysical conditions. The preliminary study indicates that the physical conditions are of great advantages to the development of grassland. There exists significant correlation between land use change and some geophysical conditions.  相似文献   

Regional characteristics of dust events in China     

WANG Shigong  WANG Jinyan  ZHOU Zijiang  SHANG Kezheng  YANG Debao  ZHAO Zongsuo 《地理学报》2003,13(1):35-44

The regional characteristics of dust events in China has been mainly studied by using the data of dust storm, wind-blown sand and floating dust from 338 observation stations through China from 1954 to 2000. The results of this study are as follows: (1) In China, there are two high frequent areas of dust events, one is located in the area of Minfeng and Hotan in the South Xinjiang Basin, the other is situated in the area of Minqin and Jilantai in the Hexi Region. Furthermore, the spatial distributions of the various types of dust events are different. The dust storms mainly occur in the arid and semiarid areas covering the deserts and the areas undergoing desertification in northern China. Wind-blown sand and floating-dust not only occur in the areas where dust storms occur, but also extend to the neighboring areas. The range of wind-blown sand extends northeastward and southeastward, but floating-dust mainly extends southeastward to the low-latitude region such as the East China Plain and the area of the middle and lower reaches of the Yangtze River. Compared with wind-blown sand, the floating-dust seldom occurs in the high latitude areas such as North Xinjiang and Northeast China. (2) The affected areas of dust storms can be divided into seven sub-regions, that is, North Xinjiang Region, South Xinjiang Region, Hexi Region, Qaidam Basin Region, Hetao Region, Northeastern China Region and Qinghai-Xizang (Tibet) Region. The area of the most frequent occurrence of dust storms and floating-dust is in South Xinjiang Region, and of wind-blown sand in the Hexi Region. In general, the frequency of dust events in all the seven regions shows a decreasing tendency from 1954 to 2000, but there are certain differences between various dust events in different regions. The maximum interannual change and variance of dust events during this time happened in South Xinjiang Region and Hexi Region. The dust events generally occur most frequently in April in most parts of China. The spring occurred days of dust events occupied 60-70% of the whole year in Hetao Region and Northeastern China Region. However, in South Xinjiang Region and North Xinjiang Region, which was less affected by monsoon climate, dust events may occur at any time of the year, less than 50% of the events in this region occur during spring. In the remaining three regions 50-60% of the dust events occur in spring of a year.  相似文献   

1995年海南东方近海5.2级地震特征分析     

胡久常  陈金燕 《华南地震》1997,17(1):39-45

总结了１９９５年海南东方近海５．２级地震的地质背景，宏观烈度，地震序列特征，前兆异常以及地震活动与环境因子的对应关系，并提出了未来一年或稍长时间内，该区及附近地区仍存在发生５～６级地震的危险性。  相似文献   

陕西宁强胡家坝地区震旦系灯影组风暴沉积特征     

刘明博  林晋炎  高硒  王晓伟  华洪  徐乔 《城市地质》2018,(2):57-63

陕西宁强胡家坝地区新元古界震旦系灯影组出露较好,为一套碳酸盐岩和碎屑岩组合,岩性组合可划分为3段:藻白云岩段、高家山段和碑湾段,其中高家山段风暴沉积发育,为本文研究重点。风暴沉积构造特征在高家山剖面和狮子崖剖面各不相同,高家山剖面丘状交错层理发育,为风暴沉积典型特征;狮子崖剖面碎屑岩沉积可见底面构造、粒序层、水平层理现象等,灰岩层发育水平层理。通过野外实测、室内薄片鉴定等,认为高家山剖面高家山段中部化石层位为海水较浅的近源风暴沉积,而狮子崖相应层位为相对海水较深的远源风暴沉积。  相似文献   

国家级天气预报检验分析系统建设与应用   总被引：1，自引：1，他引：0       下载免费PDF全文

韦青  李伟  彭颂  薛峰  赵声蓉  张金艳  齐丹 《应用气象学报》2019,30(2):245-256

为了适应精细化预报和业务管理的发展需求,国家气象中心建设开发了基于Web的国家级天气预报检验分析系统。系统分为预报检验、检验文件解析处理、检验数据查询分析与检验平台管理4个功能模块,关键技术包括标准化的数据管理、开放式的算法模块管理与调度和检验数据的可视化分析。系统建立了规范高效的检验业务数据流程,兼容处理预报分析制作系统（MICAPS）数据、GRIB2数据、城镇报数据、自动气象站数据等其他专业气象数据,涵盖了国家级省级智能网格预报、全国城镇天气预报、定量降水预报、大城市空气质量预报等数十项检验业务产品,给出了空间分布、柱状图及数据表格等展现形式。系统为全国各级预报员、模式开发人员和管理人员提供预报检验反馈信息,为各省以及国家级预报业务考核提供了信息支撑;同时系统提供逐旬、月、年度的智能网格预报以及城镇天气预报的检验结果对比,有力支撑了智能网格预报产品业务研发和业务试验。  相似文献   

福建上杭紫金山铜金矿床地质简介   总被引：2，自引：0，他引：2  

姚金炎  彭振安 《矿产与地质》1992,6(2):89-94

以宏观角度介绍紫金山铜金矿床地质背景,论述了火山机构、次火山岩、隐爆角砾岩、围岩及围岩蚀变、矿化带及矿化特征,着重总结该矿床找矿标志,以期在地质找矿中得以借鉴。  相似文献   

博格达山白杨河地区中基性岩墙地球化学特征及其地质意义   总被引：3，自引：1，他引：3  

欧阳征健  周鼎武  林晋炎  冯娟萍 《大地构造与成矿学》2006,30(4):495-503

白杨河地区中基性岩墙地球化学研究显示,该岩墙属于亚碱性系列,为岩浆高度演化的产物,轻稀土元素适度富集,轻重稀土分异中等,Nb、Ta强烈亏损,Ti、Zr和Hf适度亏损,不相容元素(K、Rb、Ba、Sr、LREE)与Pb富集,说明该岩墙源自与俯冲作用有关的交代地幔,且在侵位过程中受到地壳物质的混染。该岩墙侵位时期可能为270~250Ma左右,为造山期后伸展环境下的产物,是中亚造山带后碰撞阶段陆壳垂向生长的重要标志。  相似文献   

导航卫星自主定轨中系统误差△Ω和△t的消除方法     

李征航  卢珍珠  刘万科  余金艳 《武汉大学学报(信息科学版)》2007,32(1):27-30

为了消除利用星间距离或速度观测值进行自主定轨时可能存在的卫星星座整体旋转和卫星钟差整体漂移的误差，提出利用单点定位的方法来研究并消除上述两项误差。当导航卫星整体旋转△Ω角时，单点定位所求得的测站经度也会偏移△Ω角，据此就能用具有精确地面坐标的控制点来测定△Ω角。当各卫星钟中均舍有系统误差△t时，利用单点定位所求得的接收机钟差中也会出现同样的误差，通过与标准时间比对就能测定△t值。算倒结果表明，该方法是有效的，可行的。  相似文献