农业自然风险评估及区域农业保险费率的确定方法   总被引：11，自引：1，他引：10       下载免费PDF全文

郭迎春  阎宜玲 《应用气象学报》1998,9(2):231-238

根据农业自然灾害的时空分布规律,对于不同地域、不同作物在不同的生长季内所遭受的自然灾害,确定出作物受灾级别和损失程度,提出农业自然灾害损失率的计算和分区方法,并制定出区域农业保险费率的确定方法。其方法和结论可供其它区域开展类似保险项目研究和业务工作参考。  相似文献   

Study of Distinctive Regional Features of Surface Solar Radiation in North and East China          下载免费PDF全文

GUAN Fulai  ZHENG Youfei  CAI Ziying  YU Changwen  ZHANG Nan 《Acta Meteorologica Sinica》2011,25(4):494-505

Solar radiation is an important energy source for plants on the earth and also a major component of the global energy balance.Variations in solar radiation incident at the earth's surface profoundly affect the human and terrestrial environment,including the climate change.To provide useful information for predicting the future climate change in China,distinctive regional features in spatial and temporal variations of the surface solar radiation (SSR) and corresponding attributions (such as cloud and aerosol) are analyzed based on SSR observations and other meteorological measurements in North and East China from 1961 to 2007.Multiple models,such as the plane-parallel radiative transfer model,empirical and statistical models,and corrclation and regrcssion analysis methods are used in the study.The results are given as follows.(1) During 1961-2007,the total SSR in North China went through a process from quickly “dimming” to slowly “dimming”,while in East China,a significant transition from “dimming” to “brightening” occurred.Although there are some differences between thc two regional variation trends,long-term variations in SSR in the two regions are basically consistent with the observation worldwide.(2) Between the 1960s and 1980s,in both North and East China,aerosols played a critical rolc in the radiation dimming.However,after 1989,different variation trends of SSR occurred in North and East China,indicating that aerosols were not the dominant factor.(3) Cloud cover contributed less to the variation of SSR in North China,but was thc major attribution in East China and played a promoting role in the reversal of SSR from dimming to brightening,especially in the “remarkable brightening” period,with its contribution as high as 70％.  相似文献   

基于AMSR-E数据的被动微波遥感干旱指数研究   总被引：2，自引：0，他引：2  

郑有飞  徐芳  詹习武  关福来  杨彬云  吴荣军 《南京气象学院学报》2009,32(2):189-195

基于2005年和2006年AMSR-E（advanced microwave scanning radiometer-earth observingsystem）的亮温,计算了8个亮温比值作为候选干旱指数。假设反演出的AMSR-E Land3土壤湿度数据能反映地表干旱程度,候选干旱指数与土壤湿度的相关性分析即能显示哪一候选干旱指数较好。选择河北省3个站点,分析了相关性较好的干旱指数的年际变化,并利用该干旱指数研究了河北省2006年3月份的干旱分布,通过比较河北省136个观测站的同期降水距平百分率,表明该干旱指数具有一定的实用性。  相似文献   

河北冬奥赛区一次夜间增温过程的数值模拟及诊断     

章鸣  连志鸾  平凡  祝善友 《大气科学》2022,46(1):168-180

夜间增温是河北冬奥赛区冬季频发的天气现象,对其进行准确的模拟与预报对赛区建设及比赛保障至关重要.本文针对河北冬奥赛区2020年2月8日夜间至9日凌晨发生的一次夜间增温过程,通过引入高分辨率地形数据,利用中尺度区域数值模式WRF4.1.5精细化再现了此次夜间增温过程,并探究了此次过程的气象特征及成因.研究结果表明:此次夜...  相似文献   

Recent climatic significance of chemical signals in a shallow firn core from an alpine glacier in the South-Asia monsoon region     

《Journal of Asian Earth Sciences》2002,20(3):289-296

There are 19 sub-tropical temperate glaciers on Mount Yulong, the southernmost currently glacier-covered area in Eurasia, controlled by the south-western monsoon climate. In the summer of 1999, a firn core, 10.10 m long, extending down to glacier ice, was recovered in the accumulation area of the largest glacier, Baishui No.1. Periodic variations of climatic signals above 7.8 m depth were apparent, and net accumulation of four years was identified by the annual oscillations of isotopic and ionic composition. The boundaries of annual accumulation were confirmed by higher values of electrical conductivity and pH, and by dirty refreezing ice layers at the levels of summer surfaces. Calculated mean annual net accumulation from 1994/95 to 1997/98 was about 900 mm water equivalent. The amplitude of isotopic variations in the profile decreased with increasing depth, and isotopic homogenization occurred below 7.8 m as a result of meltwater percolation. Variations of δ¹⁸O above 7.8 m showed an approximate correlation with the winter climatic trend at Lijiang station, 25 km away. Concentrations of Ca²⁺ and Mg²⁺ were much higher than those of Na⁺ and K⁺, indicating that the air masses for precipitation were mainly from a continental source, and that the core material accumulated during the winter period. The close correspondence of Cl ⁻ and Na⁺ indicated their common origin. The decreasing trend of Na⁺/Cl⁻ ratios with increasing depth further reflects a progressive homogenization process caused by meltwater percolation. Concentrations of SO₄²⁻ and NO₃⁻ in the core are quite low. The mean annual net accumulation in the core and the estimated ablation indicate that the average annual precipitation above the glacier's equilibrium line is 2400–3100 mm, but this needs to be confirmed by long-term observation of mass balance.  相似文献   

国内设施种植气象灾害研究进展          下载免费PDF全文

魏瑞江  王鑫 《山东气象》2021,41(4):73-81

设施种植的主要气象灾害有低温（冷冻害）、寡照、风灾、雪灾及其复合灾害等,从国内设施种植气象灾害指标、灾害监测预警、灾害风险及灾害影响等方面对前人研究成果和进展进行归纳总结。灾害指标的研究所采用的方法主要是人工控制试验或对历年实际发生的灾害样本进行分析总结;灾害监测预警方法一般是用设施内小气候或设施外气象条件作为灾害指标,将灾害指标植入计算机系统,对灾害进行监测预警;风险评估多是从灾害的危险性角度去研究,确定灾害的风险概率、风险指数等;灾害影响的研究多集中在对作物生理生态反应等方面。同时从设施种植气象灾害研究存在的薄弱环节出发,提出设施种植气象灾害指标、灾害监测预警评估方法及灾害的影响等方面仍是今后一段时间研究的重点和热点。  相似文献   

河北唐山地区盛汛期短时强降水概念模型及物理量特征分析   总被引：1，自引：0，他引：1  

花家嘉  张婉莹  陈桂万  钟方潜  周任君 《冰川冻土》2016,38(2):463-472

利用2006-2013年区域自动站降水资料以及NCEP再分析资料,应用EOF分析和中尺度天气图分析等方法对唐山地区盛汛期短历时强降水的时空分布特征、天气学概念模型以及物理量特征进行研究.结果表明：唐山东北部是短时强降水的活跃区、西南部为不活跃区,但西南部极端短时强降水更强;存在5种降水空间分布类型,分别是“一致型”“西北多型”“东南多型”“东北异常偏多型”“东北异常偏少型”.700 hPa切变线是否断裂、副热带高压及高低空急流的位置以及高低空干湿区配置决定了降水分布;短时强降水发生时局地水汽丰富,暖云层厚度较大,垂直风切变较弱,存在一定的不稳定能量,强天气威胁指数较小、0℃层较高,大多数类型都有强的水汽辐合,但“东北异常偏多型”辐合较弱,其水汽主要来源于本地.  相似文献   

WOFOST作物生长模型在国内应用研究进展     

魏瑞江  郑昌玲  王鑫  申双和 《气象科学》2023,43(3):402-411

WOFOST模型是利用计算机技术对不同生产水平下一年生作物的生长发育和产量形成进行定量分析的模拟模型,学者在WOFOST模型以及模型应用方面做了大量研究,总结WOFOST模型在我国的应用研究成果,可为保障粮食安全和农业的可持续发展提供技术支撑。本文采用分类归纳法,简要阐述了WOFOST模型在我国的应用研究历程及进展,应用研究主要涉及对WOFOST模型参数的敏感性分析、模型的适用性分析、模型的改进以及对模型的应用等4个方面。针对模型应用中存在的薄弱环节及发展所需,加强对模型参数的敏感性分析、加强对模型的本地化应用或改进、加强对模型参数的升尺度研究、加强模型与多学科多技术融合4个方面将是今后WOFOST模型的研究重点。  相似文献   

A Late-Eocene palynological record from the Hoh Xil Basin,northern Tibetan Plateau,and its implications for stratigraphic age,paleoclimate and paleoelevation     

《Gondwana Research》2016

The Hoh Xil Basin, lying in the central Tibetan Plateau, is key to understanding the Cenozoic tectonics, paleoelevation and paleoclimate changes that have occurred in the Tibetan Plateau since the collision of the Indian and Asian tectonic plates. However, the stratigraphic age and paleoelevation indicated by the sediments of the Hoh Xil Basin remain hotly debated. Here we report on one palynological record from the TTH-C section, extracted from the Yaxicuo Group (the stratigraphic unit between the Fenghuoshan and Wudaoliang groups), and analyze its implications for stratigraphic age, paleoclimate and paleoelevation in the Hoh Xil Basin. The record shows that palynological taxa are mainly dominated by xerophytic Ephedripites, Nitrariadites (Nitrariapollis) and Chenopodipollis, with few ferns and conifers. Rich morphologies correspond well with those in the Xia Ganchaigou Formation (Fm) of the Qaidam Basin to the north. Palynological percentages are well correlated with the middle member of the Xia Ganchaigou Fm in the Qaidam Basin as well as the lower member of the Mahalagou Fm in the Xining Basin to the northeast. The ages of the middle member of the Xia Ganchaigou and lower member of the Mahalagou Fms from these two basins are both identical to the Bartonian Stage (~ 40–37 Ma) of the Late Eocene, according to their respective high-resolution magnetostratigraphic dating. This means that the age of the Yaxicuo Group at least covers the Bartonian Stage. Besides the Qaidam and Xining basins, the palynological assemblages of the TTH-C section are also similar to those of three other sites (the Jiuquan, Tu-ha and Hetao basins), indicating similarly arid climates dominated by a northwestern Chinese subtropical high, and a relatively low paleoelevation in the Hoh Xil Basin (mostly < 2000 m a.s.l.) in the Late Eocene.  相似文献   

华东地区夏季云微物理结构的飞机观测分析   总被引：1，自引：1，他引：0  

郝囝  陈景华  濮梅娟  周学东  吕艺影 《气象科学》2019,39(4):524-531

利用飞机搭载云粒子探头对2014年8月12-28日华东地区云的空间分布特征进行了探测,分析了云的垂直结构和水平分布特征,结合同时探测的气溶胶数据,探讨了云与气溶胶的相互作用关系。探测结果表明,安徽地区层状云云滴平均数浓度在24~297 cm^-3,液态含水量在0.04~0.13 g·m^-3,云滴数浓度随云底高度升高而减小,云滴粒径则随云底升高而增大。层积云(Sc)和雨层云(Ns)的云滴数浓度在云底最高,随高度上升浓度下降,液态含水量在云中部最高,云顶和云底处较低,高层云(As)云滴数浓度和液态含水量峰值均出现在云中上部。云的水平分布不均匀,云粒子双峰分布区域对应液态含水量高值区。Ns对气溶胶清除作用明显,清除方式以活化清除为主、碰并清除为辅。  相似文献