接到地灾报告后……

7月23日上午9时,博爱县国土资源局接到许良镇郭顶村委报告：该村东沟处道路出现塌方。灾情就是命令,国土局接到报告后,立即启动防灾预案,值班局长朱勤忠立即带领应急小组冒着大雨赶赴现场,同时通知许良镇政府和许良国土资源所一同前往。     

陕北黄土高原地区极端降水事件时空分布特征

以陕西省北部6个气象站点1959-2011年逐日降水数据为基础,采用百分比方法确定各站点极端降水阈值,选取极端降水量、极端降水频率、极端降水强度、暴雨量、暴雨日数、大雨量和大雨日数,分析陕北黄土高原地区极端降水事件时空变化特征,结果表明:(1)极端降水经历近30年的持续减少后,近10多年增加较快,各极端降水指数空间上均呈自东南向西北的递减趋势.(2)极端降水量2000～ 2011年最大,极端降水阈值和极端降水量自东南向西北递减分布.(3)极端降水频率以2000～ 2011年最大,极端降水强度变化趋势不明显.空间分布上极端降水频率以绥德最高,榆林最低;极端降水强度以洛川最高,横山最低.(4)暴雨量和暴雨日数均以2000～2011年最高,空间分布呈自东而西递减,分别形成以绥德和延安、横山和吴起为中心的高值和低值区域.大雨量和大雨日数以1959 ～1969年最高.空间分布上呈自南而北的递减趋势,均形成以洛川和横山为中心的高值和低值区域.     

Intraseasonal Oscillation of the South China Sea Summer Monsoon and Its Influence on Regionally Persistent Heavy Rain over Southern China

The intraseasonal oscillation（ISO） in the South China Sea summer monsoon（SCSSM） and its influence on regionally persistent heavy rain（RPHR） over southern China are examined by using satelhte outgoing long wave radiation,NCEP/NCAR reanalysis,and gridded rainfall station data in China from 1981 to 2010.The most important feature of the ISO in SCSSM,contributing to the modulation of RPHR,is found to be the fluctuation in the western Pacific subtropical high（WPSH）,along with a close link to the Madden-Julian oscillation（MJO）.Southern China is divided into three regions by using rotated empirical orthogonal functions（REOFs）for intraseasonal rainfall,where the incidence rate of RPHR is closely linked to the intraseasonal variation in rainfall.It is found that SCSSM ISOs are the key systems controlling the intraseasonal variability in rainfall and can be described by the leading pair of empirical orthogonal functions（EOFs） for the 850-hPa zonal wind over the SCS and southern China.Composite analyses based on the principal components（PCs） of the EOFs indicate that the ISO process in SCSSM exhibits as the east-west oscillation of the WPSH,which is coupled with the northward-propagating MJO,creating alternating dry and wet phases over southern China with a period of 40 days.The wet phases provide stable and lasting circulation conditions that promote RPHR.However,differences in the ISO structures can be found when RPHR occurs in regions where the WPSH assumes different meridional positions.Further examination of the meridional-phase structure suggests an important role of northward-propagating ISO and regional air-sea interaction in the ISO process in SCSSM.     

河套地区大雨以上降水日数的气候变化特征分析

选取河套地区87个气象站1961—2010年逐日降水量资料,采用线性趋势分析、Morlet小波分析等方法,分析河套地区大雨以上降水日数的时空分布特征其及气候变化规律。结果表明:该地区大雨以上降水日数空间分布呈现"东南多、西北少",其中,年均大雨以上降水日数超过5.0 d的区域位于其东南部,包括山西南部、河南西北部和陕西东南部;该地区7月、8月、6—9月及年大雨以上降水日数总体上均呈减少趋势,其日数变化具有明显的阶段性,大雨多发期和少发期交替出现;1985年前后年均大雨以上降水日数在该地区不同区域存在增多和减少的区别;近50 a,该地区7月、8月、6—9月和年大雨以上降水日数变化的周期性显著,其变化既存在明显的2~4 a周期,也存在6~8 a周期。     

A Study on Water Vapor Transport and Budget of Heavy Rain in Northeast China

The characteristics of moisture transport and budget of widespread heavy rain and local heavy rain events in Northeast China are studied using the NCEP--NCAR reanalysis 6-hourly and daily data and daily precipitation data of 200 stations in Northeast China from 1961--2005. The results demonstrate that during periods with widespread heavy rain in Northeast China, the Asian monsoon is very active and the monsoonal northward moisture transport is strengthened significantly. The widespread heavy rainfall obtains enhanced water vapor supply from large regions where the water vapor mainly originates from the Asian monsoon areas, which include the East Asian subtropical monsoon area, the South China Sea, and the southeast and southwest tropical monsoon regions. There are several branches of monsoonal moisture current converging on East China and its coastal areas, where they are strengthened and then continue northward into Northeast China. Thus, the enhanced northward monsoonal moisture transport is the key to the widespread heavy rain in Northeast China. In contrast, local heavy rainfall in Northeast China derives water vapor from limited areas, transported by the westerlies. Local evaporation also plays an important role in the water vapor supply and local recycling process of moisture. In short, the widespread heavy rains of Northeast China are mainly caused by water vapor advection brought by the Asian monsoon, whereas local heavy rainfall is mainly caused by the convergence of the westerly wind field.     

日本气象厅将采用新的大雨洪水警报发布标准

日本气象厅将从2008年5月28日起,采用新的大雨警报和洪水警报发布标准。目前是以1、3小时和24小时降雨量作为判断是否发布警报的标准。但是,仅以降雨量为标准发布大雨、洪水警报,精确度不够。为此,气象厅决定废除24小时降雨量这一标准,增加土壤雨量指数作为判断是否发布大雨警报的标准,增加流域雨量指数作为判断是否发布洪水警报的标准。土壤雨量指数是根据土壤中积存雨水的量来判断发生泥石流或山体滑坡可能性的指标,流域雨量指数根据流入附近河流雨量来判断发生洪水可能性的指标。     

峨眉山之雨量

地理位置欲充分了解峨眉多雨之原因必先明瞭其地理位置。峨眉位北纬二十九度二十八分,东经一○三度四十一分,居四川西南部,去省会成都一五0公里.其山自东高起拔海三0七0公尺,山巅高出峨眉县城二公里,在岷江流域     

图片新闻

近期,修武县连降大雨,该县国土资源局对辖区各地质灾害隐患点进行严密监测。8月2日,该局局长王仕国带领有关人员,冒雨对各地质灾害隐患点进行逐一查看。图为在西村乡洞湾村一隐患点现场查看。     

青岛地区气旋大—暴雨的过程模式

气旋是产生大－暴雨的主要天气系统之一，根据青岛地区产生大－暴雨的特点，将气旋大－暴雨划分三个阶段，根据气旋发生前７００ｈＰａ影响系统和低层锋区上冷暖锋形式的方式，将气旋分焊接类气旋和波动类气旋。     

青海省东部地区一次大雨天气过程成因分析

利用常规实况资料,对2008年8月19日晚发生在青海省东部的大雨天气的环流背景、影响系统以及造成降水与多个物理量场的对应关系进行了分析。结果表明：西南暖湿气流与西压槽底分裂冷空气在青海省东部交绥是导致青海省东部地区大雨的主要原因,各物理量场的高低空合理配置和高能、高湿是此次降水出现必备的动力和能量条件。