多普勒天气雷达资料与乡镇雨量资料的同步显示   总被引：1，自引：0，他引：1  

陈德生  魏延涛  崔炳俭  徐远远  曲楠 《气象与环境科学》2008,31(4):79-81

通过对新一代多普勒天气雷达终端显示软件的更新和配置文件夹下数据信息的修改,可将河南省GPRS乡镇雨量监测网络系统建立的SQL雨量数据库中所有关键点的每分钟雨量值,实时叠加显示在雷达探测到的反射率产品中,实现反射率因子和降水率之间的直观对比,帮助业务人员准确使用雷达产品.  相似文献   

遥感影像分类方法在水体面积估算中的比较研究   总被引：4，自引：0，他引：4  

张成才  窦小楠  张楠  张颖 《气象与环境科学》2008,31(3):24-28

随着遥感技术的广泛应用,利用遥感影像提取水体信息为水文研究提供了基础数据.目前进行水体提取所使用的遥感数据分辨率较低,影响了水体提取的精度.Landsat TM遥感影像主要依据水体在7个波段上光谱的不同特征以及其他地物与水体的区别,通过分析水体及背景地物的光谱值,利用单个波段或多个波段组合来提取水体信息.以昭平台水库的TM数据为例,对其进行了几种提取水体信息方法的研究.通过总体精度及Kappa系数的对比,选择最优分类方法,并将该方法用于水体面积的估算.  相似文献   

《地图学》网络教学系统的研制与应用   总被引：1，自引：0，他引：1  

江南  刘玉峰  陈志勇  郑声远 《测绘通报》2005,(8):65-67

通过对<地图学>教学规律的深入研究,利用网络技术、数据库技术、多媒体技术建立起资源丰富、功能强大的网络教学系统,改变传统教学方式在时空上的限制,以及教学手段落后、学习资料缺乏的局面,为学生成为学习主体提供优越环境.  相似文献   

自1:10000比例尺DEM提取地形起伏度--以陕北黄土高原的实验为例   总被引：10，自引：2，他引：8  

朱红春  陈楠  刘海英  汤国安 《测绘科学》2005,30(4):86-88

地形的起伏是反映地形起伏的宏观地形因子,是比较适合区域水土流失评价的地形指标,在区域性研究中,利用DEM数据提取地形起伏度能够快速、直观的反映地形的起伏特征。1∶10000比例尺DEM具有越来越广泛、重要的应用,系统探讨基于其提取地形起伏度的方法具有重要的理论和实践意义。本研究以陕北黄土高原不同地貌区的DEM数据为实验数据,依据地貌发育的基本理论,GIS的窗口递增分析方法结合自然地理单元———小流域划分方法,通过对比分析,确定不同地貌区的地形起伏度。通过对实验结果的对比分析证明,该方法是一种比较通用、有效的方法。  相似文献   

广东某硫酸冶炼工业区土壤铊污染及评价   总被引：4，自引：0，他引：4  

刘敬勇  常向阳  涂湘林  陈南  付善明  刘慧 《地质论评》2009,55(2):242-250

运用地累积指数法(Igeo)及富集指数法(EF)对广东某硫酸厂含铊黄铁矿冶炼废渣堆渣场周围土壤铊污染状况进行了调查和评价。结果表明,废渣周围土壤已受到了明显的土壤铊污染,铊污染物主要集中在土壤0~165cm范围,并且表现出沿垂直方向向下迅速降低的特点;土壤表层的铊吸附量未达到饱和状态,铊污染物将继续在土壤表层发生累积作用。Igeo与EF法对铊污染评价结果相似：废渣下伏土壤0~6cm范围铊污染达到中度污染水平,而在土壤约85~15cm以下为无至轻度污染水平;15cm以下没有受到土壤铊的污染;相对于下伏土壤剖面,废渣外围土壤污染更为严重,其中表层土壤0~1cm铊已经达到显著污染,土壤2~105cm范围内铊为中度污染,而在土壤约15cm以下铊为无至轻度污染。两种方法应用于工业区土壤铊污染水平分析是可行的,但是不能表明铊在土壤中存在状态、迁移能力以及生物有效性。  相似文献   

内蒙古元宝山区花岗岩的地球化学特征及构造环境初探          下载免费PDF全文

张术根  刘南  丁俊  高翔  魏黎  杨惠钫 《地质找矿论丛》2009,24(4):341-348

通过将赤峰元宝山区碱长花岗岩和二长花岗岩的地球化学数据与国内外各类型花岗岩对比和判别,认为内蒙元宝山区花岗岩属于A型花岗岩,具有富硅、富碱、贫钙镁,微量元素出现Sr,P,Eu,Ti的低谷,稀土配分模式曲线呈右倾、富轻稀土、典型的海鸥式等A型花岗岩特点。利用Eby A型花岗岩构造环境判别图解判断岩体为A1型,而且是与大陆造陆抬升有关的A型花岗岩类。  相似文献   

辽宁沿海早、中期全新世海进中的一次海退事件探讨          下载免费PDF全文

方晶  武亚芳  李瑞武  周江  康玲玲  柴锐  马楠 《地学前缘》2009,16(2):396

通过分别对辽东半岛东侧大洋河平原中部的D65孔岩心做连续的硅藻分析,以及对辽东半岛西侧的长兴岛八岔沟古泻湖平原B3孔、下辽河平原的机械钻孔X33及手动钻孔X11和X21等钻孔岩心做连续的粘土混浊水电导率测定,得到各岩心的硅藻图谱/或粘土混浊水电导率图谱。显示出在这些海岸平原均有厚度在6m以上的海相层存在。表明全新世海侵时海水达到并长期占据这些海岸平原。同时还显示在这些海相地层的5～7m深处,普遍存在一层陆相或海陆交互相地层,通过对各地点已有的14C年代数据分析,推测这层陆相层或海陆交互相地层应该形成于全新世海面上升的早全新世—中全新世时期。表明全新世海进期当中,辽宁沿海普遍存在一次海退地质事件。从下辽河平原样品的14C测年数据,推测这次海退时期大致在9300～8000aB.P.(校正年)。  相似文献   

Supercontinent formation from stochastic collision and mantle convection models   总被引：3，自引：3，他引：0  

Nan Zhang  Shijie Zhong  Allen K. McNarmara 《Gondwana Research》2009,15(3-4):267-275

The large-scale tectonics in the last billion years (Ga) are predominated by the assembly and breakup of supercontinents Rodinia and Pangea. The mechanisms controlling the assembly of supercontinents are not clear. Here, we investigate the assembly of a supercontinent with 1) stochastic models of randomly-moving continental blocks and 2) 3-D spherical models of mantle convection with continental blocks. For the stochastic models, we determined the time required for all the blocks to assemble into a single supercontinent on a spherical surface. We found that the assembly time from our stochastic models is significantly longer than inferred for Pangea and Rodinia. However, our study also suggests that the assembly time from stochastic models is sensitive to the rules for randomly assigning continental motion in the models. In our dynamic models of mantle convection, continental blocks are modeled as deformable and compositionally distinct materials from the mantle. We found that mantle convective planform has significant effects on supercontinent assembly. For models with moderately strong lithosphere and the lower mantle relative to the upper mantle that lead to degree-1 mantle convection, continental blocks always assemble to a supercontinent in  250 million years (Ma) and this assembly time is consistent with inferred for Pangea and Rodinia. However, for models with intrinsically small-scale mantle flows, we found that even when continental blocks merge to form a supercontinent, the assembly times are too long and the convective structures outside of supercontinent regions are of too small wavelengths, compared with observed.  相似文献   

Research and perspectives on geomorphology in China: Four decades in retrospect     

Weiming Cheng  Qiangyi Liu  Shangmin Zhao  Xiaoyu Gao  Nan Wang 《地理学报(英文版)》2017,27(11):1283-1310

Geomorphology is one of the main subdisciplines of geography. The research achievements and prospects in geomorphology have received considerable attention for a long time. In this paper, a general retrospect of geomorphologic research in China over the past 60 years was firstly addressed, especially the research progress during the last 40 years. Based on a summary of experience and a tendency of development, perspectives of geomorphologic research direction in the future were provided. It is concluded that the discipline of geomorphology has made great progress in the aspects of geomorphologic types, regionalization, as well as their subdisciplines such as dynamic geomorphology, tectonic geomorphology, climatic geomorphology, lithological geomorphology, palaeogeomorphology. We believe that persisting in the unity principle between morphological and genetic types would be conductive for the development of traditional landforms and integrated landforms. In addition, five perspectives aim to enhance China’s geomorphologicl research capacity were proposed. They are: (1) strengthening the research of basic geomorphologic theory and the research of integrated geomorphology to expand the research space; (2) focusing more on the research of geomorphologic structure and geomorphologic function to improve the application ability of geomorphology; (3) constructing a comprehensive resource, environmental, and geomorphologic information system and building a sharing platform to upgrade the intelligent information industry of geomorphology; (4) putting more efforts on the research of coastal geomorphology and marine geomorphology to assist the transformation of China from a maritime country to an ocean power; and (5) cultivating talents and constructing research teams to maintain a sustainable development of China’s geomorphologic research.  相似文献   

一种基于TVDI模型的煤田温度异常区面积提取方法研究     

朱小强  塔西甫拉提&#  特依拜  依力亚斯江&#  努尔麦麦提  张飞  戴岳  夏楠  张淑霞 《干旱区地理》2017,40(3):622-632

选用Landsat 8 资料构建了地表温度（Ts）与归一化植被指数（NDVI）的Ts-NDVI特征空间,计算了温度植被干旱指数（TVDI）。利用MODIS温度产品数据和实地野外采样数据进行精度验证确定煤田火区TVDI阈值。通过对遥感影像的地表热异常信息进行定性与定量分析继而对煤田温度异常区边界信息进行挖掘。结果表明：（1）利用野外实测土壤相对含水量进行验证,反演值与实测值的相关系数R²=0.66,表明干旱指数的反演精度较高,相关性较好。（2）TVDI模型对温度呈现出较高的敏感性,二维散点图集中在1∶1 线上,对NDVI的敏感性较低,有利于识别温度异常区。（3）利用MVC最大合成法,建立TVDI-MVC作为精度验证数据,火区面积为5.03 km²,其中TVDI-SC提取火区精度最大为98.50%,TVDI-SW2提取火区精度最小为88.98%。可见煤田温度异常区范围较广,潜在的灾情恶化较严重。  相似文献