厄尔尼诺持续时间与大气环流异常形势

针对不同持续时间的El Nio事件,进行了大尺度大气环流及其演变的合成分析研究.其结果清楚地表明,不同持续时间的El Nio事件的发生、发展和消亡过程,对流层低层风场和对流层高层速度势场的距平都有极为显著差异.分析得到了对El Nio事件的发生和消亡起着重要作用的大气环流异常形势.还发现对于持续时间较长的El Nio事件,东北太平洋上850hPa异常气旋性环流减弱和西北太平洋上异常反气旋性环流增强较慢,因此赤道太平洋异常西风维持的时间也较长,而与澳大利亚冬季风加强相关联的南半球西太平洋的速度势正距平的维持,对El Nio的持续也起一定作用;对应持续时间较短的El Nio事件,西太平洋上200hPa速度势正距平的迅速东移,对El Nio的迅速消亡起重要作用.     

滇、黔、桂三省（区）交界处致洪暴雨的特征分析

对滇、黔、桂三省(区)交界致洪暴雨进行了诊断分析，结果表明，该地区致洪暴雨发生要达到一定的能量、水汽及抬升运动，暴雨的落区位于高能、高湿舌区的辐合中心，且湿舌、能舌主要存在于对流层中、低层，当其向上伸展得越高，暴雨强度越大、持续时间越长。     

江西省2006年1-12月自然灾害公报(摘录)

受气候异常影响,2006年江西自然灾害总体发生水平与常年相比,属偏重发生年份。全省自然灾害主要以台风、暴雨洪涝、雷电、地质灾害、农林生物灾害为主。其中风雹、雷电灾害频繁,雷电死亡人数     

基于MODIS数据的额尔齐斯河上游河冰物候研究

额尔齐斯河发源于中国新疆阿尔泰山南坡,是中国唯一流入北冰洋的河流.随着中俄"冰上丝绸之路"提出,额尔齐斯河通航具有重要意义,监测其河冰物候变化显得尤为必要.本研究基于2001—2018年MOD09GQ第2波段数据,分析了额尔齐斯河布尔津至斋桑泊段每年河冰物候信息,包括开始封河时间、结束开河时间、冰/雪最大覆盖时间、冰期...     

EXPERIMENTS OF INFLUENCE OF DISCHARGE PROCESS ON CHANNEL PATTERN

Based on experimental data and theory, by means of simplified discharge durations in a small flume,the influence of discharge process on channel morphology and channel pattern was analyzed in this paper. It was concluded that on the same original channel, different discharge and channel conditions would end with different river morphology, including thalwegs and radius of bends. Different discharge process resulted in two kinds of change:tiny change in the process of “big-small-big” and distinct change in the process of “small-big-small”. Flood discharge duration was verified to be the main cause in the discharge process. Proper discharge process will change the morphologies of river, even can led to channel pattern transformation. The influences based on the relationship between the flow and the channel itself, including slope and riverbed constitution. Although not be a main cause, original channel morphology may influence its final channel pattern. Neglecting the influence of channel itself will hamper the understanding of channel patterns.     

2011年1月1日江苏建湖ML3.5地震的震源机制

据江苏数字地震台网测定：2011年1月1日前后,在江苏省建湖、阜宁交界地区发生了一次有感震群活动,最大震级为M_L3.5,时间为2011-01-01 T17：07,地点位于建湖（ψ_N33°30′,λ_E119°50′,见图1）。 由观测资料反演地震的震源机制,是地震部门的基础性工作之一,对认识震源的破裂情况具有重要意义。中、小地震,震源尺度较小,震源破裂的持续时间较短。     

地震和爆炸的P波层析成像——第二部分：由时频地震图得到的2004年苏门答腊-安达曼地震的断层破裂特征（英文）

本文分析了2004年12月26日苏门答腊-安达曼地震的宽频带地震图。目的是通过不同频率成分的子事件的发生时间了解断层的破裂过程。具体分析的是由相应宽频带地震记录得到的P波的时频地震图。分析结果说明,在S波到达前的时窗内发生了最大辐射强度的相应频率低于1 Hz的15次较大子事件,但在同样的时窗内,还发生了最大辐射强度的频...     

Impact of Meteorological Drought on Streamflow Drought in Jinghe River Basin of China

Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environ- ment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by local govern- ments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can pro- vide timely information for effective water resources management. In this study, streamflow drought is detected by using the Standard- ized Runoff Index, whereas meteorological drought is detected by the Standardized Precipitation Index. Comparative analyses of fre- quency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China, mainly providing the following findings. 1） Eleven meteorological droughts and six streamflow droughts were indicated during 1970 and 1990 after pooling using Inter-event time and volume Criterion method. 2） Streamflow drought in the Jinghe River Basin lagged meteorological drought for about 127 days. 3） The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. 4） The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theo- retical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought mitigation and regional water resources management.     

雾霾影响生活 治霾刻不容缓——雾霾天气对群众生活影响程度调查

近段时间,雾霾的波及范围之广、持续时间．之长引起了人们的极大关注和担忧,雾霾治理已作为重大民生问题摆在政府的议事日程上。为了解当前群众对雾霾天气的看法和受影响程度,为雾霾治理工作提供最基层的群众民意,更好地促进雾霾治理,北京市海淀区统计局专项调查科4月份通过计算机辅助电话系统（CATI）在全区范围内开展了雾霾天气对群众生活影响度的调查。     

暴雨为何致灾

暴雨本身是一种自然现象,但也是我国最主要的灾害性天气之一。也就是说,暴雨具有潜在的破坏力和危险性。如果一场暴雨没有直接造成生命伤亡和社会财产损失,就不是暴雨灾害。暴雨是否造成灾害,有几方面的因素,除取决于降雨强度、持续时间以及发生暴雨的时间等自然因素外,