气象部门高层次人才评价研究     

王梅华  刘蕊 《气象科学进展》2020,10(2):78-82

人才评价是人才发展体制机制的重要组成部分,是人才资源开发与管理的前提。在分析总结气象部门高层次人才评价现状基础上,构建气象部门高层次人才评价指标体系,提出了高层次人才评价的优化路径,为气象部门合理建设高层次人才队伍提供理论支撑。  相似文献   

川藏公路“102”滑坡群的基本特征     

张晓刚  王成华  孔纪名  朱平一 《山地学报》1998,(2)

“102”滑坡群位于川藏公路西藏波密县境内的通麦“102”地段.该地段滑坡成群分布,在约3km长的范围内,共有大小滑坡22处,其中直接危害川藏公路且规模较大的滑坡有6处.  相似文献   

对流层高层偏北气流在梅雨暴雨中的作用   总被引：11，自引：0，他引：11  

翟国庆 《气象学报》1998,56(1):68-76

文中对江淮梅雨暴雨过程中的高低空流场特征及物理过程进行分析．结果表明：对流层上部青藏高原东侧常有高空偏北大风轴汇入南亚东风急流中．在这支强北风轴北端发现高空辐散和辐散的增长．亦即有利于低层辐合上升的持续、发展和加强;表明了低层西南急流与高空青藏高压东侧的偏北强风轴之间的次级环流圈,有利于梅雨暴雨的持续．  相似文献   

Assessing damaged road verges as a suspended sediment source in the Hampshire Avon catchment,southern United Kingdom     

A. L. Collins  D. E. Walling  R. W. Stroud  M. Robson  L. M. Peet 《水文研究》2010,24(9):1106-1122

Diffuse sediment pollution impairs water quality, exerts a key control on the transfer and fate of nutrients and contaminants and causes deleterious impacts on freshwater ecology. A variety of catchment sediment sources can contribute to such problems. Sediment control strategies and effective targeting of mitigation options therefore require robust quantitative information on the key sources of the sediment problem at catchment scale. Recent observations by Catchment Sensitive Farming Officers (CSFO's) in England have highlighted road verges damaged and eroded by passing vehicles, particularly large farm machinery, and livestock herd movement as visually important potential sources of local sediment problems. A study was therefore undertaken to assess the relative importance of damaged road verges as a suspended sediment source in three sub‐catchments of the Hampshire Avon drainage basin, southern UK. Road verge sediment contributions were apportioned in conjunction with those from agricultural topsoils and channel banks/subsurface sources. Time‐integrating isokinetic samplers were deployed to sample suspended sediment fluxes at the outlets of two control sub‐catchments drained by the Rivers Chitterne and Till selected to characterize areas with a low road network density and limited visual evidence of verge damage, as well as the River Sem sub‐catchment used to represent areas where road verge damage is more prevalent. The findings of a sediment source fingerprinting investigation based on a combination of intermittent sampling campaigns spanning the period 22/5/02–27/4/08 suggested that the respective overall mean relative sediment contributions from damaged road verges were 5 ± 3%, 4 ± 2% and 20 ± 2%. Relative inputs from damaged road verges for any specific sampling period in the River Sem sub‐catchment were as high as 33 ± 2%. Reconstruction of historical sources in the same sub‐catchment, based on the geochemical record stored in a floodplain depth profile, suggested that the significance of damaged road verges as a sediment source has increased over the past 15–20 years. The findings provide important information on damaged road verges as a primary source of suspended sediment and imply that catchment sediment control strategies and mitigation plans should consider such verges in addition to those agricultural and channel sources traditionally taken into account when attempting to reduce sediment pressures on aquatic resources. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Impact of road‐generated storm runoff on a small catchment response     

Daniel W. Woldie  Roy C. Sidle  Takashi Gomi 《水文研究》2009,23(25):3631-3638

The impact of road‐generated runoff on the hydrological response of a zero‐order basin was monitored for a sequence of 24 storm events. The study was conducted in a zero‐order basin (C1; 0·5ha) with an unpaved mountain road; an adjacent unroaded zero‐order basin (C2; 0·2 ha) with similar topography and lithology was used to evaluate the hydrological behaviour of the affected zero‐order basin prior to construction of the road. The impact of the road at the zero‐order basin scale was highly dependent on the antecedent soil‐moisture conditions, total storm precipitation, and to some extent rainfall intensity. At the beginning of the monitoring period, during dry antecedent conditions, road runoff contributed 50% of the total runoff and 70% of the peak flow from the affected catchment (C1). The response from the unroaded catchment was almost insignificant during dry antecedent conditions. As soil moisture increased, the road exerted less influence on the total runoff from the roaded catchment. For very wet conditions, the influence of road‐generated runoff on total outflow from the roaded catchment diminished to only 5·4%. Both catchments, roaded and unroaded, produced equivalent amount of outflow during very wet antecedent conditions on a unit area basis. The lag time between the rainfall and runoff peaks observed in the unroaded catchment during the monitoring period ranged from 0 to 4 h depending on the amount of precipitation and antecedent conditions, owing mainly to much slower subsurface flow pathways in the unroaded zero‐order basin. In contrast, the lag time in the roaded zero‐order basin was virtually nil during all storms. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

基于乡村人口转移和农村道路建设的空间贫困破解机理及其对策研究——以贵州省为例   总被引：1，自引：0，他引：1  

冯应斌  龙花楼 《地理研究》2019,38(11):2606-2623

贫困与地理环境之间交互耦合形成了空间贫困陷阱,本文在对贵州50个国家级贫困县乡村人口转移减贫效应和松桃、威宁、望谟3个典型县域贫困村贫困发生率与农村道路可达性指数空间耦合关系进行实证研究基础上,阐释了破解空间贫困的作用机理,并构建相应政策体系。结果表明：① 贵州国家级贫困县乡村户籍人口向县内城镇转移和县外转移具有显著的减贫效应,但县内城镇转移比县外转移减贫效应的作用力更大。② 松桃县、望谟县极度贫困、可达性较差型和深度贫困、可达性较差型贫困村所占比例在15%左右,威宁为10%左右,对该类型贫困村实施整村易地搬迁和村庄撤并;对具有自然历史文化特色资源的深度贫困、可达性中等型和一般贫困、可达性中等型贫困村应进一步扩展道路宽度,打通断头路,形成网络,增强通行能力。③ 应坚持以县城为中心的就地城镇化和发达地区中心城市、省会城市等异地城镇化并重,加强对转移劳动人口的技能培训,提升其城镇生存能力。继续加大对具有自然历史文化特色资源的保护类村庄的“通村、通组、通户”道路拓宽、硬化等措施,逐步完善自来水、宽带等较为薄弱的基础设施投入力度,推进贫困村基本公共服务均等化;通过发展山区“绿水青山”内生性和外生性产业,引导贫困人口提升自我发展能力。  相似文献   

基于大数据的极端暴雨事件下城市道路交通及人群活动时空响应   总被引：2，自引：1，他引：2  

易嘉伟  王楠  千家乐  马廷  杜云艳  裴韬  周成虎  涂文娜  刘张  王会蒙 《地理学报》2020,75(3):497-508

随着全球气候变化加剧,极端降雨增多,暴雨内涝灾害频发,严重威胁城市的可持续发展。快速掌握暴雨给城市交通及人群的影响,有助于提高灾害应急管理水平和事件响应能力。利用实时动态的交通路况信息和手机定位请求数据,通过一种融合STL时序分解技术与极端学生化偏差统计检验的时间序列异常探测方法,监测和分析暴雨内涝灾害事件中,城市道路交通和人群活动的时空响应特征,并以2018年7月16日发生在北京的极端暴雨事件为例开展实证研究。研究结果显示,在降雨集中的早、晚高峰两个时段（8—9时、18—19时）,市区的拥堵道路数量超出往常水平最高可达150%,异常检测分析显示拥堵道路数量和交通拥堵指数均达到异常甚至极端水平。人群活动的异常响应分析结果显示,暴雨事件引起定位请求量异常升高、异常点增多,且异常点的空间分布与1 h前的降雨量分布存在较高相关性。以上结果不仅证明了大数据及异常检测方法对于快速洞察暴雨事件对城市交通及人群影响的有效性,也为城市暴雨内涝灾害的应急响应与管理提供了新的技术手段。  相似文献   

基于行道树的道路快速提取和面积计算研究     

李成范  周廷刚  刘岚 《地理信息世界》2008,6(6)

在城市遥感中,道路自动(半自动)提取一直是研究的霞点.本文在现有道路自动(半自动)提取技术的基础上,结合高分辨率遥感影像中行道树的分布特点,从地学知识出发,利用归一化筹值植被指数、阀值分割、数学形态学算子及地理信息系统的分析功能等实现基于行道树的道路自动(半自动)提取和道路面积快速、自动计算.结论表明基于行道树的道路提取和面积计算方法具有一定的实用性.  相似文献   

道路收费站计重收费系统的设计与实现     

陈盈  陶宏才 《成都信息工程学院学报》2007,22(1):31-35

主要介绍了开发某道路收费站计重收费系统的方法和实现过程。系统采用SQL Server 2000作为数据库后台，实现计重收费数据和属性数据的统一管理，前台则是在，NET环境下利用C#编程实现，提供对收费站内相关信息的查询和编辑功能。  相似文献   

顾及几何特征和拓扑连续性的道路网匹配方法     

秦育罗  宋伟东  张在岩  孙小荣 《测绘通报》2021,(8):55-60

已有的道路网匹配方法需要一定的人为干预和控制,仍无法实现匹配自动化,而且对于具有一定尺度差异的数据而言,受不相关道路对象的影响,匹配结果中会存在较多的误匹配。为此,本文提出一种顾及几何特征和拓扑连续性的由粗匹配到精匹配的分层匹配策略。粗匹配阶段,利用短边中位数Hausdorff距离计算匹配对象的相似度,再以道路网弧段端点的近邻分析结果作为匹配阈值,判断匹配对象是否为同名实体;精匹配阶段,将粗匹配阶段评价结果中离散的同名实体构建为完整的道路Stroke,即以追踪的方式剔除误匹配和添加漏匹配。利用宿城区不同尺度的道路网对所提算法进行验证,结果表明,该算法具有较好的匹配效果,能够实现匹配自动化。  相似文献