模式识别方法在华东地区的应用——地震危险区划分          下载免费PDF全文

谢华章  王爱玲 《地震地质》1989,11(2):7-15

按I.M.Gelland等人建立的模式识别Cora-3修改算法研究华东地区的地质构造、地貌和地球物理特征并用于识别本地区破坏性地震。破坏性地震易发生在新构造运动的沉降区内、白垩纪或新生代构造(断陷)盆地的内部或边缘、新构造垂直差异运动的地质块体边界附近以及活动断层数较多的地方。 “投票”结果表明误识率较低(ε=0.061—0.098)。根据“投票”结果,划分出五个D节点相对密集的地震危险区。 控制试验表明识别结果是比较稳定和可靠的  相似文献   

专家系统在 TM 图像分类中的应用     

匡霞  陈贻运  戴昌达 《遥感学报》1989,(4)

提高TM图像的分类精度,是图像处理及应用领域中一个很重要的研究课题。本文在总结已有成果基础上,首先利用现有的统计分类技术,对待分类图像进行预分类,并检测出“不确定”像元。然后综合光谱、地理、土壤类型、早期判别结果、目视判读经验等各种知识和信息,充分发挥专家系统的推理判断能力,对“不确定”像元的类别作进一步判别,使得整幅图像的分类精度得到改善。并据此初步建立了一个土地利用的分类系统。试验证明,这种分类方法的精度比仅用单一多光谱信息的统计分类法(最大似然法)提高约8％。  相似文献   

图像的空间频谱识别与分类   总被引：2，自引：0，他引：2  

汪逢熙 《测绘学院学报》1995,(4)

本文介绍一种光学－计算机混合处理系统对图像进行空间频谱分析的原理和方法。该系统的光学部分是一个夫琅和费衍射装置，它把光学图像转换成二维的傅立叶频谱，即空间频谱。计算机则负责频谱数据的采集与分析。鉴于遥感地质日视解译中区分岩类的主要识别指标是遥感图像的影纹特征，文中以岩石的遥感图像的空间频谱采样与特征提取，对空间频谱进行识别和分类为例，阐明利用衍射图样对图像进行识别的方法。  相似文献   

山西省降水规律特性研究     

杨普义 《地下水》2007,29(4):1-3

以降水的成因和来源为基础出发点,对山西省的降水发生发展和分布特点进行全面研究,分析其在时间和空间上的变化趋势和特点,对水资源根本基础进行深入探讨,为整个地区的水资源分析评价和水资源发展战略规划及水生态和水环境保护提供科学参考依据.  相似文献   

运用图型动力学观点研究地震的孕育与发生     

兰从欣  郭大庆  杨立明  郭心 《中国地震》2000,16(1):37-47

从细观损伤力学及损伤演化的角度探索地震活动中的演化诱致发震是一种全新的方法.本文简要介绍了细观损伤演化诱致突变理论和图型动力学的基本原理,并对首都圈地区张家口-渤海地震带上ML 5.0以上地震进行分析研究.结果表明,实际震例与图型动力学理论存在较好的一致性,按演化的最终状态可分为两种演化模式,即整体稳定模式(GS模)和演化诱致突变模式(EIC模),两模式间没有明显界限,存在过渡区,过渡区明确给出了地震孕育过程的不确定性和随机影响的作用.此研究为地震预报提供了更为科学的思路和方法.  相似文献   

Simulated Influence of the Atlantic Multidecadal Oscillation on Summer Eurasian Nonuniform Warming since the Mid-1990s     

Xueqian SUN  Shuanglin LI  Xiaowei HONG  Riyu LU 《大气科学进展》2019,(8):811-822

Based on ensemble experiments with three atmospheric general circulation models(AGCMs), this study investigates the role of the Atlantic Multidecadal Oscillation(AMO) in shaping the summer nonuniform warming over the Eurasian continent since the mid-1990 s. The results validate that the positive-phase AMO can indeed cause nonuniform warming,with predominant amplified warming over Europe–West Asia and Northeast Asia, but with much weaker warming over Central Asia. The underlying mechanism is then diagnosed from the perspective that the boundary forcing modulates the intrinsic atmospheric variability. The results highlight the role of the Silk Road Pattern(SRP), an intrinsic teleconnection pattern across the subtropical Eurasian continent propagating along the Asian jet. The SRP can not only be identified from the AGCM control experiments with the climatological sea surface temperature(SST), but can also be simulated by the AMO-related SST anomaly(SSTA) forcing. Furthermore, diagnostic linear baroclinic model experiments are conducted, and the results suggest that the SRP can be triggered by the AMO-related tropical diabatic heating. The AMO-triggered SRP-like responses feature anticyclonic circulations over Europe–West Asia and Northeast Asia, but cyclonic circulation over Central Asia. These responses cause increased warm advection towards Europe–West Asia and Northeast Asia, reduced precipitation and cloud cover, and then increased downward shortwave radiation. This increased warm advection and increased downward shortwave radiation together cause amplified warming in Europe–West Asia and Northeast Asia. The situation is opposite for Central Asia.  相似文献   

Possible connection between anomalous activity of Scandinavian Atmospheric Teleconnection Pattern and winter snowfall in the Yangtze-Huaihe River Basin of China          下载免费PDF全文

ZHU Lin  CHEN Haishan 《大气和海洋科学快报》2019,(3):218-225

利用中国地面气候资料日值数据集(V3.0)逐日气象资料研究了我国江淮冬季降雪的时空变化及其与斯堪的纳维亚遥相关型(SCAND)的可能联系。结果表明:江淮冬季降雪表现出空间一致的年际变化,SCAND与江淮地区冬季降雪异常关系密切。江淮冬季降雪偏多通常对于SCAND正位相,500hPa阻塞高压、东亚大槽加强,有利于冷空气活动增强,江淮地区垂直运动增强,水汽输送增强;降雪偏少则对应SCAND负位相。研究结果有助于深入理解江淮冬季降雪异常的相关机理。  相似文献   

珠江口赤潮生成的天气分型研究     

任湘湘  何恩业  李海  蔡怡 《海洋预报》2007,24(3):46-58

赤潮的爆发是生物、化学、物理等多因素综合作用的结果。温度、风力、风向、气压等气象条件,海况、潮汐、海流及海水的理化特征,如海水温度、盐度、营养盐、微量元素等都是赤潮爆发的重要因子或诱导因素。当前由于海洋生态领域的数值预报仍不成熟,国内的赤潮预测主要还是依靠经验和统计方法为主,如气象条件预报法、水文条件预报法、化学条件预报法、生物条件预报法、卫星遥感预报法或是综合预报法等。本文根据2001年～2005年《沿海海洋赤潮专报》中广东省阳江到汕尾沿海(112°～116°E)即珠江口地区发生赤潮的记录,使用NCEP再分析数据,从气象条件诱发赤潮的角度分析得出最易引发珠江口赤潮的5种天气形势,并用相关性分析方法得出其中两种天气形势的典型场,对预测珠江口沿海的赤潮发生具有一定的指导意义,可在实践中加以应用。  相似文献   

神经网络计算机及其在遥感应用中的展望     

谈正 《遥感学报》1991,(3)

本文概述了神经网络计算机的基本特点、神经网络的形式化描述、目前国际上神经网络计算机的现况以及在遥感图像处理中应用的潜力和展望。  相似文献   

Interannual variation of East Asian summer monsoon and its impacts on general circulation and precipitation     

YU Shuqiu  SHI Xiaohui  LIN Xuechun 《地理学报》2009,19(1):67-80

Using NCEP/NCAR reanalysis geopotential height (GHT) and wind at 850 hPa, GHT at 500 hPa, precipitation rate, sea level pressure (SLP) and precipitation observations from more than 600 stations nationwide in June–August from 1951 to 2006, and focusing on the East Asia–West Pacific region (10o–80oN, 70o–180oE), interannual variation of East Asian summer monsoon (EASM) and its correlations with general circulation and precipitation patterns are studied by using statistical diagnostic methods such as 9-point high pass filtering, empirical orthogonal function (EOF) analysis, composite analysis and other statistical diagnosis, etc. It is concluded as follows: (1) EOF analysis of SLP in the East Asia–West Pacific region shows the existence of the zonal dipole oscillation mode (APD) between the Mongolia depression and the West Pacific high, and APD index can be used as an intensity index of EASM. (2) EOF analysis of GHT anomalies at 500 hPa in the East Asia–West Pacific region shows that the first EOF mode is characterized with an obvious meridional East Asian pattern (EAP), and EAP index can also be used as an EASM intensity index. (3) The composite analysis of high/low APD index years reveals the close correlation of APD index with EAP at 500 hPa (or 850 hPa). The study shows an obvious opposite correlation exists between APD index and EAP index with a correlation coefficient of –0.23, which passes the confidence test at 0.10 level. (4) Both APD and EAP indexes are closely correlated with precipitation during flood-prone season in China and precipitation rate over the East Asia–West Pacific region. The significant correlation area at 5% confidence level is mainly located from the southern area of the Yangtze River valley to the ocean around southern Japan, and the former is a positive correlation and the latter is a negative one.  相似文献