Relationship between surface pollen assemblages and vegetation in Luonan Basin,Eastern Qinling Mountains,Central China

The catchment of South Luohe River in Central China is an important region for investigating modern pollen-environment relationship, because it is located in the transitional zone between south and north China, an environment which is sensitive to climate changes. In this study, 40 surface samples under ten vegetation types were collected to reveal the relationship between pollen assemblages and vegetation. The results show that the surface pollen assemblages reflect the vegetation quite well. In forest topsoils, the average of arboreal pollen content is greater than 40%, and the Selaginella sinensis spore is high. As to sparse forest grassland and shrub community, the average arboreal pollen is 13.2% and 16.6% respectively, and the shrub pollen is relatively higher than that of grassland samples. The grassland and farmland are characterized by low percentage of tree and shrub pollen (<10% and <1%), and high percentage of herbs (>80%). Pinus, Quercus and some other arboreal pollen can indicate the regional vegetation because of their dispersal ability. Quercus pollen is under-representative and so is Pinus. Artemisia pollen is significantly over-represented, has poor correlation with the plant coverage, and may reflect human disturbance. Gramineae can indicate plant quite well, but with low representation. High content of Chenopodiaceae probably suggests human impact. Predominant Selaginella sinensis can be used as an indicator of forest environment. Cluster analysis and principal components analysis of pollen assemblages can distinguish forest and non-forest vegetation well. The former method is better at separating pine and mixed forests, while the latter is more stable and could better differentiate farmland and other non-forest area. The first axis of PCA mainly reflects the humidity.     

Using a Bayesian estimator to combine information from a cluster analysis and remote sensing data to estimate high-resolution data for agricultural production in Germany

In Germany, a county-resolution data set that consists of 35 land-use and animal-stock categories has been used extensively to assess the impact of agriculture on the environment. However, because such environmental effects as emission or nutrient surplus depend on the location, even a county resolution might produce misleading results. The aim of this article is to propose a Bayesian approach which combines two sorts of information, with one being treated as defining the prior and the other the data to form a posterior, used to estimate a data set at a municipality resolution. We define the joint prior density function based on (i) remote sensing data, thus accounting for differences in county data and missing data at the municipality level, and (ii) the results of a cluster analysis that was previously applied to the micro-census, whereas the data are defined by official statistics at the county level. This approach results in a fairly accurate data set at the municipality level. The results, using the proposed method, are validated by the national research data centre by comparing the estimates to actual observations. The test statistics presented here demonstrate that the proposed approach adequately estimates the production activities.     

A new MODIS daffy cloud free snow cover mapping algorithm on the Tibetan Plateau

Because of similar reflective characteristics of snow and cloud, the weather status seriously affects snow monitoring using optical remote sensing data. Cloud amount analysis during 2010 to 2011 snow seasons shows that cloud cover is the major limitation for snow cover monitoring using MOD10A1 and MYD10A1. By use of MODIS daily snow cover products and AMSR-E snow wa- ter equivalent products （SWE）, several cloud elimination methods were integrated to produce a new daily cloud flee snow cover product, and information of snow depth from 85 climate stations in Tibetan Plateau area （TP） were used to validate the accuracy of the new composite snow cover product. The results indicate that snow classification accuracy of the new daily snow cover product reaches 91.7% when snow depth is over 3 cm. This suggests that the new daily snow cover mapping algorithm is suitable for monitoring snow cover dynamic changes in TP.     

人工影响天气作业装备研发和应用进展

人工影响天气科学活动持续了将近70 a,其作业装备和技术方法均得到了很大的发展,已经形成空中和地面一体化作业体系。以美国、加拿大、澳大利亚、以色列、南非、泰国等为代表的国家主要使用飞机和地面发生器开展人工影响天气作业。以俄罗斯、中国、保加利亚等为代表的国家在使用飞机和地面发生器的同时,也使用火箭(或高炮)开展人工影响天气作业。随着高性能飞机的投入使用,播撒技术和催化剂配方的不断研发改进,人工影响天气作业装备整体水平有了明显的发展和提高。文章分别介绍了国内外人工影响天气飞机及机载作业装备、火箭和高炮、地面发生器、常用催化剂的研发和应用情况及未来发展趋势。     

河北春季一次飞机人工增雪的综合分析

2013年4月19日,河北省人工影响天气办公室在河北中南部地区根据云系特点首次采用多层次水平催化和垂直验证的方式对层状云进行人工催化和探测。本文利用机载仪器所取得的飞机探测资料,结合实时天气、卫星、雷达、探空和雨量观测资料,分析了河北春季层状云增雪作业的技术指标,探讨了航测微物理参量和卫星、雷达、探空等资料在作业中的应用。结果表明：云在发展期雷达回波由15 dBZ逐步上升到25-35 dBZ,卫星反演的云顶高度、云顶温度、有效粒子半径、光学厚度等都有增加;云在中后期有效粒子半径、光学厚度、液水路径迅速下降,雷达回波同时减弱。在高度3 177-5 723 m之间过冷云滴达100-700个/cm^3,含水量在0.01 g·m^-3左右,最大0.081 g·m^-3,云粒子主要在此增长,形成降水粒子,该区间适宜催化。作业后,影响区内云体发展,雷达回波增强,出现35 dBZ强回波,且强回波中心扩大;卫星反演的云顶高度、光学厚度等比对比区有明显增加。     

梅雨锋云系的模态研究Ⅱ：出现频率及转换特点

基于经验正交函数（EOF）分解方法提取的1998～2008年梅雨活跃期共16次过程的梅雨锋云系主导模态,讨论了这些主导模态的发生频率、维持时间及相互转换特征。结果表明,在16个梅雨活跃期内,云系的第1主导模态正相位出现的频率最高,并且在4个活跃期内作为首次出现模态率先出现;第5模态正位相的出现频率最低,且该模态多数伴随其他模态一同出现,为过渡模态。统计发现,各主导模态的维持时间并不相同,其中第2模态负位相持续时间最长,为81 h;第5模态正位相的最大持续时间最短,仅为18 h;第6模态负位相的平均持续时间最长。对不同主导模态转换方向和频次的计算表明,各个位相的模态最多（最少）向9种（3种）（含正负位相）其他模态进行转换。除第6模态负位相和第5模态负位相向其他模态的转化具有较好的方向性外,其他模态间的相互转换多表现出随机性特征。其中,第6模态负位相在超过半数的情况下向第5模态负位相转换,而第5模态负位相则多向第3模态正位相和第1模态负位相进行转换。     

一次强雷暴中的多灾种天气特征对比分析

用Micaps和NCEP再分析资料对2012年7月3日发生在淮河以南地区的大范围强雷暴天气进行了分析,得出高、低空急流配置,形成低空辐合,高空辐散,槽线由高到低前倾,有利增强大气不稳定层结,中尺度切变线南北摆动具有触发对流作用等,为该区强雷暴多灾种天气的发生,提供了动力和热力条件。从云图、雷达参数和地闪特征对比分析得出冰雹、雷击、强降水,分别发生在强对流云团发展的不同时间和不同部位。其云团的形态、强度和范围等也不同。冰雹所表现出的回波强度、回波顶高和垂直积分液态水含量为最强,雷击次之,强降水最弱。在地闪出现的各个阶段都有可能出现雷击事故,但多为负地闪,强度均较强。强降水过程多为负地闪,强度较弱,降水集中时段,地闪频次高。冰雹发生时地闪频数明显下降,且多为正闪。雷击过程强度和陡度变化最平缓,冰雹过程突变最明显。雷击发生在整个地闪过程中强度和陡度都相对较大的时刻;冰雹发生前约半小时有强度和陡度的骤增;强降水阶段地闪平均强度和陡度都最小。     

一种语音识别的可定制云计算方法

以云的方式提供语音识别服务是1种新的趋势。当前市场上的语音云都是面向通用领域的,针对这一现状,提出了1种面向特定领域,可定制的,可满足用户个性化需求的云计算方案。首先介绍了语音识别的MapReduce过程,接着描述了基于Sector/Sphere的语音识别系统组成及语音识别的Sphere处理流程,并给出了语音识别系统的云计算架构,然后探讨了语音识别的可定制实现,最后进行实验评估,证明云计算架构的语音识别系统与传统C/S架构的语音识别系统相比更具优势,且具有一定的可扩展性。     

基于SaaS的区域非职业体育赛事云服务平台的设计与实现

与传统软件架构模式相比,云计算具有综合成本较低、部署快速、规模调整灵活等优势,针对区域非职业体育赛事在信息采集、组织管理、赛果处理与发布等赛事运营、组织、管理等方面存在的不足,从平台构建的可行性、架构与功能等方面,讨论并实现了一种基于SaaS模式的非职业体育赛事云服务平台,最后从使用效益等方面总结该平台对于提升区域非职业体育赛事组织与管理所取得的促进作用。     

一种基于DCT变换的数字水印算法在“天地图·广东”中的应用

地理信息公共服务通过云平台进行部署和发布,可以使得其应用于政府部门和社会的空间数据服务更加高效和稳定。然而,把对应的地图信息挂载在云平台供应商处同时也加大了防止电子地图被盗用的难度。本文针对"天地图?广东"的电子地图瓦片,提出了一种具有高鲁棒性、基于离散余弦变换(DCT)的数字水印算法,在寄存云端和公开发布的电子地图中隐藏生产单位版权的数字水印图片,藉此来跟踪、抵制"天地图"图片数据的非法流通,非法复制,有效地保护数据生产单位的合法权益。