我国中东部平原地区临界气温条件下降水相态判别分析   总被引：1，自引：0，他引：1  

陈双  谌芸  何立富  郭云谦 《气象》2019,45(8):1037-1051

基于2001—2013年地面观测和探空资料,对地面气温位于0～2℃(以下称临界气温)我国降雪的时空分布及其与降雨的垂直热力特征进行了研究,引入了决策树判别方法对上述条件下雪和雨进行了判别分析,结果表明:临界气温下降雪出现频率总体高于降雨、雨夹雪出现频率,且在我国华北南部至江南北部的中东部地区分布较多,年均可达7.69～15.38站次;临界气温下,降水相态为雨或雪对应的平均温度廓线最大差异位于650 hPa附近,且地面气温较低时,平均温度差异更明显,平均湿度廓线差异则主要位于低层,且在地面气温较高时,平均湿度差异更明显;临界气温下,降水相态为雨时,地面上空存在暖层样本占比,较降水相态为雪时更高,且降雨时暖层主要位于中层,降雪时暖层则主要位于低层,降雨时其暖层强度显著大于降雪时暖层强度;在临界气温下雨雪判别分析中,地面气温能显著提升判别准确率,湿球温度能在一定程度上提升判别准确率,基于云顶温度、中层融化参数、低层湿球温度构建的决策树判别模型,判别准确率达到91.86%,能较好地解决临界气温下雨和雪的判别问题。  相似文献   

气象因子对半冬性小麦灌浆速度的影响效应研究     

信志红  郭建平  谭凯炎  张利华  孙义  杨荣光 《气象》2019,45(12):1736-1746

选用黄淮海冬麦区4个半冬性小麦品种郯麦98、山农18、徐麦33、皖麦52为试验材料,通过分期播种试验,利用方差分析、相关分析、逐步回归和通径分析等方法,分析半冬性小麦籽粒灌浆速度变化趋势和气象因子对灌浆速度的影响。结果表明,正常播期冬小麦灌浆速度波动性最小、千粒重最大,迟播10 d冬小麦灌浆速度波动性最大、千粒重最小;华北区品种郯麦98灌浆速度表现最稳定、千粒重最高,而黄淮区品种皖麦52灌浆速度最大;半冬性小麦灌浆持续期为35～39 d;南北气候差异是影响各品种冬小麦灌浆速度不同的原因之一。半冬性小麦各播期灌浆速度的变化趋势一致,灌浆速度变化与相关显著气象因子的变化规律相符合;灌浆速度峰值期一般出现在开花后15～25 d,迟播冬小麦最大灌浆速度出现时间较对照处理提前,不利于提高粒重;气温条件对冬小麦灌浆速度影响显著,其中最高气温要素是影响不同播期品种灌浆速度的共有关键因子。通径分析表明,最高气温对灌浆速度的作用由自身的直接效应决定,而日照时数与最低气温对灌浆速度的作用与间接效应一致;最高气温平均值对灌浆速度的影响最重要,日照时数和最低气温平均值对灌浆速度的影响较弱;最高和最低气温平均值、日照时数均为灌浆速度的限制因子,其中最高气温平均值对灌浆速度变化的决策作用最大。  相似文献   

甘肃矿业的经济社会支撑度分析          下载免费PDF全文

陈国誉  刘建宏 《甘肃地质》2007,16(4):21-25

甘肃是我国矿产资源相对丰富的省区之一,矿种齐全,分布面广,部分矿种的探明资源储量大,有色和贵金属矿产具有比较优势。在经济持续快速发展的新时期,矿产资源的经济社会支撑和保障能力是需要认真分析的战略问题。本文从甘肃实际出发,以统计数据为依据,分析了矿产资源对甘肃经济社会发展的支撑能力,提出了矿产资源开发和可持续利用的政策措施。  相似文献   

Developing a building policy for the erosion zone: Solutions to some key (Dutch) questions     

P.R. Winckel  J.K. Vrijling  J. van de Graaff 《Coastal Engineering》2008

In those coastal communities where the most seaward strip of mainland consists of dunes, these dunes often serve as a flexible sea defence. In addition, this strip offers large potential for housing and commercial enterprises. Unfortunately, due to severe storm surges part of this strip (the erosion zone) is subject to erosion, and as a result of which any buildings or infrastructure located here, are destroyed. Therefore, as we will illustrate in this paper, a building policy for this zone should reflect a compromise between two opposite interests: exploitation of the existing potential and, prevention of an unacceptable high risk due to erosion. Accordingly, the authors have developed a framework for such a building policy on the basis of which the desirability of various different types of investments and the location within the erosion zone of such investments can be determined. The examples that are used to illustrate this framework in this paper are limited to experiences in The Netherlands as relevant data and experiences are available and relatively easy accessible here. Nevertheless, the approach as is described is generic and applicable worldwide suggesting that the discovered unused potential for exploitation is not just limited to The Netherlands.  相似文献   

测绘生产项目人力资源管理系统的开发     

徐剑平  张学之  周博飞 《测绘与空间地理信息》2009,32(1)

地理信息数据加工生产行业在项目管理的方式和方法上,存在着先进的生产力与不先进的管理方式相矛盾的问题.如何解决人力资源与生产项目的高效结合,使劳动力分配效能在项目管理中实现最大化,是一个无法回避和必须解决的课题.本文基于地理信息数据生产项目管理的实际应用,介绍系统的设计思想、技术路线、系统功能以及数据库的设计.随着本系统的不断推广和应用,一定能为地理信息数据加工生产行业的项目人力资源管理开拓新的模式,并为项目管理者提供有效的决策支持.  相似文献   

Mapping of moraine dammed glacial lakes and assessment of their areal changes in the central and eastern Himalayas using satellite data     

Sazeda BEGAM  Dhrubajyoti SEN 《山地科学学报》2019,(1):77-94

The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes(MDGLs) in the recent past have increased the risk of glacier lake outburst floods(GLOF) in the countries of Nepal and Bhutan and in the mountainous territory of Sikkim in India. As a product of climate change and global warming, such a risk has not only raised the level of threats to the habitation and infrastructure of the region, but has also contributed to the worsening of the balance of the unique ecosystem that exists in this domain that sustains several of the highest mountain peaks of the world. This study attempts to present an up to date mapping of the MDGLs in the central and eastern Himalayan regions using remote sensing data, with an objective to analyse their surface area variations with time from 1990 through 2015, disaggregated over six episodes. The study also includes the evaluation for susceptibility of MDGLs to GLOF with the least criteria decision analysis(LCDA). Forty two major MDGLs, each having a lake surface area greater than 0.2 km2, that were identified in the Himalayan ranges of Nepal, Bhutan, and Sikkim, have been categorized according to their surface area expansion rates in space and time. The lakes have been identified as located within the elevation range of 3800 m and6800 m above mean sea level(a msl). With a total surface area of 37.9 km2, these MDGLs as a whole were observed to have expanded by an astonishing 43.6% in area over the 25 year period of this study. A factor is introduced to numerically sort the lakes in terms of their relative yearly expansion rates, based on their interpretation of their surface area extents from satellite imageries. Verification of predicted GLOF events in the past using this factor with the limited field data as reported in literature indicates that the present analysis may be considered a sufficiently reliable and rapid technique for assessing the potential bursting susceptibility of the MDGLs. The analysis also indicates that, as of now, there are eight MDGLs in the region which appear to be in highly vulnerable states and have high chances in causing potential GLOF events anytime in the recent future.  相似文献   

结合生态恢复的某工程边坡支护设计     

高鹏  陈征宙  邵长云  何清雨  刘裕华 《高校地质学报》2006,12(3):404-409

以浙南火山岩地区某工程边坡为例,研究了坡面绿化方法在具体工程中的应用。计算了坡面绿化中镀锌铁丝网对边坡稳定性的作用,考虑了厚层基材喷射绿化方法应用在岩质高陡边坡上可能存在的稳定性不足。根据坡面绿化对坡面整体性强化作用小的特点设置格构梁,结合坡面生态恢复的生态学原理,提出了结合坡面绿化的边坡支护方案  相似文献   

中国户外运动网站信息流对人流生成的导引机制分析--以乐游户外运动俱乐部网站为例   总被引：8，自引：1，他引：7  

王杨  路紫  孙中伟  孙静怡 《地球信息科学学报》2006,8(1):84-90

本文以乐游户外运动俱乐部网站为案例,探讨中小型“自我依托”户外运动俱乐部网站信息流对人流生成的导引作用问题,认为这种作用经过网站访问者的信息获取、知识转化、认知与决定的过程而发生,经过网站交流媒介的信息、集聚、交流和组织四种平台而完成。本文也初步确定与信息流对人流生成的导引作用相关的决策影响要素,认为计划、资金、会员以及赞助商和媒体4种要素对俱乐部网站的良好运行能起到决定性作用。通过将网站使用者作为出发点来研究虚拟一现实组织特征,也能发现许多信息社会人文地理学发展的问题。  相似文献   

Application of participatory principles to investigation of the natural world: An example from Chile     

Sarah Schumann 《Marine Policy》2010

Participatory research in environmental and natural resources-related fields is premised on many of the same notions that underlie participatory processes in decision making. This study examines one instance of participatory research to assess the extent to which the documented benefits of participatory decision-making hold up in the context of research. A survey of Chilean shell-fishers engaged in research with marine biologists assesses the relationships between four variables: fishers’ participation in research, fishers’ opinions of biologists, fishers’ trust in biologists, and fishers’ acquisition of knowledge from biologists. Results illuminate the multidimensionality of these variables and suggest that complex interrelationships between them make the benefits of participatory research more nuanced than those reported for participatory decision-making. For instance, participatory research may provide low benefits when participatory research outcomes differ little from those produced solely by scientists. In addition, high-cost scenarios may result when outcomes of participatory research are inferior to those produced solely by scientists. A third downside may result when participation leads participants to increase their deference to scientific knowledge, thereby defeating the corroborative purpose of their participation. A fourth effect may occur when increased trust by in scientists results from participation, decreasing participants’ perceived need to take part in research.  相似文献   

海洋交通风险应急决策系统设计与实现     

汪靖  林植  靳焰 《海洋通报》2010,29(1)

针对海洋交通风险事故的特点,采用基于分层推理思想设计了海洋交通风险应急决策处理模型。在模型中提出了以行为和状态为核心的知识规则描述方法。以该模型为基础给出了系统的设计与实现。通过将海洋交通风险事故分解为事务级、情况级和执行级三级处理,使系统能综合应用海洋交通事务各种信息进行有效决策,提高了海洋交通事务风险控制能力。系统的实现对于促进海洋交通风险控制的智能化水平,深化海事管理信息化平台建设具有现实意义。  相似文献