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.     

气象数据图形显示系统及应用

当前复杂繁多的气象数据格式,给气象预报与科研工作人员的绘图工作带来了困难。针对这个问题,分析和研究了国内外气象图形软件的特点及不足,基于Meteoinfo类库特点,选择利用C#、VB语言构架界面,FORTRAN后台运行进行数据处理,GIS的地理信息功能和GrADS的批处理的混合编程方案,开发了气象数据图形显示系统,有助于把气象工作者从编写脚本和数据转换的不便中解放出来,让气象工作者能够有更多的时间做研究或业务。     

安徽省冬小麦春霜冻害气象指标的研究

本文根据安徽省12个农业气象观测站冬小麦春霜冻害观测调查数据,针对不同品种(春性和半冬性)冬小麦,全面分析了拔节期前15 d至拔节后20 d的最低气温变化规律,以日最低气温为指标,将春霜冻害等级划分为轻度和重度2个级别,并分时段确定等级。验证结果表明,虽然春霜冻害的发生受地形、土壤等多种因素的影响,但最低气温指标基本能够反映出冬小麦拔节前后不同品种春霜冻害的发生规律,可以在霜冻监测预警业务中应用。用该指标进行霜冻发生风险分析的结果表明,安徽省冬小麦主产区为轻度霜冻频发区、重度霜冻基本不发区,冬小麦春性品种春霜冻高发区比半冬性品种明显偏南,可用于指导冬小麦品种合理布局,减轻春霜冻危害风险。     

北京急性脑血管疾病与气象要素的关系及预测

基于2006年1月至2010年12月北京市120急救中心的逐日脑血管急症接诊病例数据资料,首先探讨北京市急性脑血管疾病与气象要素的关系,选取不同季节的影响因子,然后根据概率积分方法将发病人数划分为4个级别,并采用人工神经元网络方法(artificial neural network,ANN)分别建立了北京市不同季节的急性脑血管疾病预测模型。研究结果表明:(1)急性脑血管疾病发病人数存在明显的季节性变化和日变化特征,冬春季发病人数高于夏、秋季,发病主要集中在早晨到中午的09—14时;(2)发病人数相对于气象要素存在明显的滞后效应,夏和冬秋季发病分别与高温高湿、冷空气活动有关;(3)脑血管疾病预测模型通过对新样本进行预报,除夏季外,完全准确率高于30%,预报误差≤±1级的准确率高于60%,研究成果对于预防急性脑血管疾病发病和调度120急救车辆等应急措施具有较好的科学参考价值。     

新疆博州气象条件对棉花产量的影响分析

气象条件对棉花产量有着明显的影响,分析总结博州棉花生产受气象条件影响的关键因子和关键时段,将为保证博州棉花高产稳产提供科学依据。本文利用新疆博州1997－2012年的棉花产量、生育期、和气象资料,采用直线回归拟合方法分离出气象产量,并与棉花全生育期内各时段的气象要素进行相关分析,总结出博州棉花生产受气象条件影响的关键因子和关键时段。结果表明,4月中、下旬播种出苗期,降水和日照是影响博州棉花产量的主要影响因子;５月幼苗期,降雨日数和日照时数是影响棉花产量的关键因子;６月处于五叶和现蕾期,气温和日照是影响棉花产量的关键因子;7月是博州最热的季节,棉花处于开花期,并开始结铃,降水和气温是影响棉花生长的关键因素;8-９月棉花裂铃和吐絮期,博州出现影响棉铃生长的高温干旱和低温寡照天气不明显。最后针对博州棉花生产提出了气象服务重点工作建议,为搞好气象为农服务,为博州棉花高产稳产提供了科学依据。     

Characteristics of the Regional Meteorological Drought Events in Southwest China During 1960–2010

An objective identification technique for regional extreme events(OITREE) and the daily compositedrought index(CI) at 101 stations in Southwest China(including Sichuan, Yunnan, Guizhou, and Chongqing)are used to detect regional meteorological drought events between 1960 and 2010. Values of the parameters of the OITREE method are determined. A total of 87 drought events are identified, including 9 extreme events. The 2009–2010 drought is the most serious in Southwest China during the past 50 years. The regional meteorological drought events during 1960–2010 generally last for 10–80 days, with the longest being 231days. Droughts are more common from November to next April, and less common in the remaining months.Droughts occur more often and with greater intensity in Yunnan and southern Sichuan than in other parts of Southwest China. Strong(extreme and severe) regional meteorological drought events can be divided into five types. The southern type has occurred most frequently, and Yunnan is the area most frequently stricken by extreme and severe drought events. The regional meteorological drought events in Southwest China have increased in both frequency and intensity over the study period, and the main reason appears to be a significant decrease in precipitation over this region, but a simultaneous increase in temperature also contributes.     

风云气象卫星数据处理算法的若干创新

This study introduces some innovations in the data processing algorithm for Chinese FY meteorological satellites. Issues about satellite image navigation, radiation calibration, and data assimilation are discussed.
A time series of the earth＇s disk center-line count provides information on the orientation of the satellite spin axis. With this information, the altitude parameters of the satellite and then the earth disk location in the south-north direction may be solved. In each spin cycle, the satellite views the sun and the earth. Given the satellite position and altitude, the angle （β） subtended at the satellite by the sun and the earth can be calculated and predicted. Thus, the earth＇s disk location in the east-west direction is fixed. Based on this principle, we derived an automatic image navigation algorithm for FY2 geosynchronous meteorological satellites with an accuracy approaching pixel level.
The FY2 meteorological satellite traveling in a geostationary orbit suffers a large amount of radiation from the sun. The radiation varies on both diurnal and annual scales, which causes radiation responses in the thermal infrared （IR） bands wherein the wavelengths greater than 3.5 μm vibrate periodically on scales of hours to years. These vibrations must be precisely calibrated. First, based on the accurate estimation of the radiant contribution from the front-optics, the variation characteristics of the calibration parameters are obtained on a temporal scale of hours from the space-borne inner-blackbody （IBB） measurement results. Second, the in-orbit measured radiation of the lunar surface is referenced and utilized to correct the sys- tematic bias of the IBB calibration from daily to annual scales. By using such algorithms, we achieved a calibration accuracy of the FY2 satellite＇s IR imagery of less than 1 K.
The on-orbit satellite instrument parameters play an important role in data quality; however, they may be mis-measured due to limitations in the measurement conditions or may be     

地市级集约化气象影视制作平台的研究与应用

通过对本单位气象影视的现有资源进行升级改造,在投入极少资金配置硬件的情况下,充分发挥地市级人才技术和设备优势,自主设计开发炫影系统,建立地市级集约化气象影视制作平台。炫影系统采用节目模块化制作流程,通过气象符号叠加、特效模板组合、节目模块拼接等,可轻松地完成多套节目的同时制作。公用模块部分程序设计,采用内存虚拟盘作为暂存,对视频编码进行优化,高效率使用内存,极大提高了共享数据的访问速度。在视频采集的设计上采用独特的蓝溢出抑制功能,强化了彩色校正级别,通过模糊技术来处理可能因为细节丢失而发生的蓝溢出。炫影系统还提供视频和图形特技统一的三维设计空间,引入模板物件和透视模块层的概念,实现模板编辑三维创意交互。在节目网络传输方面采用虚拟专用网,使气象影视真正实现主动式光网传输。"集中制作、末端分发"的地市级电视气象节目集约化模式的运行,从整体上提高了气象影视节目的制作水平,增强了节目的可看性,促进了气象影视节目的品牌形成。通过对集约化气象影视制作平台的研究,地市级的公共气象服务能力和覆盖面得到了极大提高,气象灾害预警更加及时准确,社会公众的防灾避险能力得到加强。该系统平台的研究也适用气象灾害现场电视节目应急制作发布,也为今后建设高标准集约化气象影视网络制作平台提供借鉴。     

气象影视节目中外景的拍摄

气象影视节目一直是具有实用性、服务性的电视节目。随着生活的丰富,所需信息量的增加,节目的形式也随之越来越多变。文章主要分析了几种特殊天气的外景拍摄,并探讨了外景拍摄中需注意的事项,得出气象影视节目在形式上有所创新,才能够在新媒体时代具有竞争力并更好的服务社会。     

湛江市东海岛一次强雷暴天气过程分析

利用广东省闪电探测系统资料、卫星云图资料、探空资料及雷击点附近的风廓线雷达、多要素自动站等资料,对发生在湛江市东海岛气象综合探测基地内的一次强雷暴天气过程进行综合分析。结果表明：该次强雷暴天气发生在受高空槽和弱冷空气共同影响的天气过程中,雷击电流强度一54．46366kA,雷电流上升陡度28．66508kA／μs。雷击点在低涡云团内,雷击点雷达回波强度超过45dBZ,风向从底层向上随时间顺转,雷击发生前后雷击点附近的降雨量、风向风速、本站气压和能见度等气象要素产生了明显的突变。发生雷击的当日是处在大气层结由不稳定转变为稳定的过渡时段,弱冷空气、强降水和雷暴的共同作用消耗了大气中的能量和水汽,使大气层结回复到相对稳定状态。