准噶尔南部沙尘暴发生的地表条件研究

准噶尔南部可分出沙尘暴源区、易发区和少发区(或罕见区)三类,它们包括植被状况、土壤理化性质在内的地表条件存在差异。以植被盖度、植物群落多样性和土壤表层水分为变量,在费歇(Fisher)准则下建立起源区和少发区地表特征的判别函数R=-0．0576x1-0．1345x2-0.0695x2,并确定了两者划分的阈值R0=-10．07。在此基础上,对易发区地表条件的类型归属进行判别。最终查明影响沙尘暴发生的地表条件主要是植被状况,其中最为重要的是植物群落的多样性。     

气象条件对玉米不同病害的影响差异研究

农作物在生长发育过程中和有关病原生物相遇后,还需要环境条件允许活力与病原侵染和传播,病害才可能发生或迅速发展,否则病害便不会发生[1]。研究气象条件对病虫害的发生量[2]、发生期[3]、发生程度[4]的影响及损失估计[5],对不同种类的病害进行比较研究。在齐齐哈尔市玉米丝黑穗和大小斑在整个玉米病害中所占比例极大,从1990￣2002年13a中有7a玉米的病害只发生了丝黑穗和大小斑(见表1)。选取了玉米的这两个主要病害丝黑穗和大小斑进行研究。通过对齐齐哈尔市的气象条件和这两种病害发生量的分析研究,得出气象条件对不同病害影响的差异,为不…     

模糊逻辑仿真建模及其在青岛海雾分析中的应用

引入模糊推理仿真建模方法，在传统定性分析的基础上，基于观测事实和预报经验，建立起了青岛海雾定量化的模糊推理映射模型，在此基础上对青岛海雾发生发展的影响因子和变化特征进行了诊断和预报探讨。仿真试验结果表明，模糊推理方法在定量性、客观性和自动化程度方面优于传统的天气分析预报方法，在分析、预报诸如海雾等地域性特征明显的天气中有较好的实用意义和应用前景。     

瀛海漫笔

世界上的河流无虑千万条．河名也多有变化。但因受政治风云之累而“更名换姓”的．却非常罕见。刚果(Congo)河名的更迭,则为眼皮底下最近发生的新鲜实例。     

极值理论在福建沿海地区地震预测中的研究与应用

利用陈培善等人对极值理论修改后的极值分布函数模型对1971年1月-2012年9月福建沿海地区的地震资料进行统计分析,单位时间内最小与最大地震的确定分别考虑相关区域内台网的监控能力以及删除余震后的实际情况.根据修正后的极值理论统计计算出该地区地震的复发周期及截至2015年12月可能发生的相应地震的次数与发震概率,并对有关结果进行映震能力分析,为今后福建沿海地区地震趋势分析提供可遵循的理论依据.     

地震来了怎么办

地震发生时,至关重要的是要有清醒的头脑,镇静自若的态度。只有镇静,才能运用平时学到的知识判断地震的大小和远近。近震常以上下颠簸开始,之后才左右摇摆。远震却以左右摇摆为主,而且声脆,震动小。一般小震和远震不必外逃。     

基于SuperMap的鄱阳湖综合治理信息系统关键技术研究

运用3S技术、多媒体技术、海量数据库技术、可视化建模开发技术、虚拟现实技术等,构建了鄱阳湖重点区域综合治理信息系统。系统多角度展示了环鄱阳湖周边各区县中存在的各类纠纷隐患及其原因,以及此区域上曾发生的案(事)件等信息,并能对事件的整治进展情况进行跟进和全面掌握执法力量分布情况,以便更好更科学地为综治办、渔政、海事、公安等涉湖相关单位及时排查隐患、综合治理湖区,为建设和谐鄱阳湖提供高效、快捷的服务。     

首都圈地区震源机制解综合研究

Comprehensive statistical analysis was performed on the basic features of focal mechanisms of 619 ML≥2.0 earthquakes which occurred in the capital circle area from January 2002 to June 2010. By dividing the capital area into three studying regions based on regional tectonic characteristics, cluster analysis was conducted on the focal mechanisms of all subregions using the longest distance method in the statistical cluster analysis to study the characteristics of tectonic stress tensors. The result shows that dominant P-axis azimuth distribution is NNE-NEE and that of T-axis is NNW--NWW, most of the focal areas are controlled by a horizontal stress field and rupture is mainly of horizontal strike-slip. The maximum principal compression stress orientation is NE75° in the west, NE62° in the middle, and near EW in the east of the capital area. The regional tectonic stress field is characterized by horizontal compression.     

Objective Analysis of Circulation Extremes During the 21 July 2012 Torrential Rain in Beijing

It has been reported that the heaviest rain event since 1951 hit Beijing on 21 July 2012 （henceforth referred to as the 721 case）.The frequency and extreme attributes of the large-scale circulation patterns observed during the 721 case are explored by using obliquely rotated T-mode principle component analysis （PCA） and reanalysis data from NCEP/NCAR.The occurrence frequency of the 721-type circulation during the summers of 1951-2012 is 10.9%,while the frequency of torrential rain under this type of circulation is 4.51%.Relative to other rainstorms with similar large-scale circulations during the study period,the 721 case is characterized by a more westward extension of the subtropical high over the western North Pacific,a stronger low-level jet in the lower troposphere over the south of Beijing,a larger amount of ambient precipitable water,and a stronger vertical wind shear over Beijing.Among the 621 days with the 721-type circulation during the study period,the 721 case ranks the 54th in terms of the 925-hPa low-level jet south of Beijing,the 209th in terms of the local vertical wind shear,and the 8th in terms of the local precipitable water.The 721 case is particularly extreme with respect to the 925-hPa low-level jet south of Beijing and local precipitable water.Cases with similar circulations and equal or greater values of the 925-hPa low-level jet south of Beijing and local precipitable water have occurred thrice during the summers of 1951-2012 （i.e.,once every 21 years）.     

CH/T4018―2013《基础地理信息应急制图规范》解读

1制定的背景我国是世界上遭受自然灾害影响最为严重的少数国家之一,灾害种类多,发生频率高,分布地域广,造成的损失大。基础地理信息是国家应对各类自然灾害及突发公共事件重要的基础性信息支撑。基于现有的基础地理信息数据,在事发的第一时间,快速制作应急区域各种类型的应急地图,是测绘应急高效服务的首要任务。