浅析如何做好测绘生产质量控制工作     

刘蕴杰 《测绘与空间地理信息》2012,35(11):227-228

如果说测绘生产是一项复杂工作,是获取基础数据的重要手段,那么测绘生产中的质量控制,就是测绘生产过程中的一个重要环节。本文详细讲述了如何在测绘生产中进行有效的质量控制,为提高测绘成果质量尽自己微薄之力。  相似文献   

泥石流拦砂坝底扬压力分布及影响因素试验     

陈兴长  陈慧  游勇  柳金峰 《岩土力学》2018,39(9):3229-3236

泥石流拦砂坝底的扬压力会抵消坝体的部分有效荷重,影响其抗倾覆稳定性。为了研究拦砂坝底扬压力的分布规律及其影响因素,设计制作了拦砂坝模型和扬压力采集系统,开展了不同沟床坡度和不同坝前堆积条件下的扬压力模拟试验。试验结果表明,扬压力自坝踵至坝趾不断减小,且与渗流距离呈线性关系,当坝前有堆积物时相关系数绝对值达到0.98以上;沟床坡度明显影响坝底扬压力的分布。随着沟床坡度的增加,扬压力不断减小,且对坝踵处扬压力的影响较坝趾处更大;坝底和坝前堆积物的渗透性对扬压力的影响也很显著,它们的渗透性越差,扬压力就越小;坝前堆积物的渗透性还显著影响扬压力的分布规律,渗透性越差,其分布规律性就越强。研究成果为深入研究泥石流拦砂坝底扬压力的作用过程和作用机制奠定了基础。  相似文献   

Adjustments in channel morphology due to land‐use changes and check dam installation in mountain torrents of Calabria (southern Italy)          下载免费PDF全文

Diego Fortugno  Carolina Boix‐Fayos  Giuseppe Bombino  Pietro Denisi  Juan Manuel Quiñonero Rubio  Vincenzo Tamburino  Demetrio Antonio Zema 《地球表面变化过程与地形》2017,42(14):2469-2483

In Mediterranean semi‐arid conditions, the availability of studies monitoring channel adjustments as a response to reforestation and check dams over representative observation periods, could help develop new management strategies. This investigation is an integrated approach assessing the adjustments of channel morphology in a typical torrent of southern Italy after land‐use changes and check dam construction across a period of about 60 years. A statistical analysis of historical rainfall records, an analysis of land‐use changes in the catchment area and a geomorphological mapping of channel adjustments were carried out and combined with field surveys of bed surface grain‐size over a 5‐km reach including 14 check dams. The analysis of the historical rainfall records showed a slight decrease in the amount and erosivity of precipitation. Mapping of land‐use changes highlighted a general increase of vegetal coverage on the slopes adjacent to the monitored reaches. Together with the check dam network installation, this increase could have induced a reduction in water and sediment supply. The different erosional and depositional forms and adjustments showed a general narrowing between consecutive check dams together with local modifications detected upstream (bed aggradation and cross‐section expansion together with low‐flow realignments) and downstream (local incision) of the installed check dams. Changes in the torrent bends were also detected as a response to erosional and depositional processes with different intensities. The study highlighted: the efficiency of check dams against the disrupting power of intense floods by stabilizing the active channel and the influence of reforestation in increasing hillslope protection from erosion and disconnectivity of water and sediment flows towards the active channel. Only slight management interventions (for instance, the conversion of the existing check dams into open structures) are suggested, in order to mobilize the residual sediment avoiding further generalized incision of the active channel and coast line erosion. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

我国5′×5′平均空间重力异常的计算及检核   总被引：5，自引：0，他引：5  

孙凤华 《测绘学院学报》1999,(3)

阐述了适用于5种不同情况的5′×5′网格平均空间重力异常及其中误差的计算方法;给出了计算结果和误差统计;用实测值检核了各地区的推值误差,并依此估计出本次计算的我国陆地和海洋5′×5′平均空间重力异常的总体精度约为±9×10-5ms-2。  相似文献   

CCTV新台址主楼的倾斜变形特性研究     

刁建鹏  黄声享 《测绘工程》2010,19(2):42-44

CCTV新台址主楼的塔楼双向倾斜6°,在自重恒荷载作用下,塔楼向倾斜方向变形。倾斜变形影响测量基准垂直传递的稳定性,导致施工测量存在系统偏差。文中介绍基于测量机器人的塔楼倾斜变形监测过程,分析倾斜变形规律,利用最小二乘拟合法求得塔楼的日变形速度,并根据测量基准垂直传递的限差,通过误差传播定律,确定测量基准合理的检核频率,保证了塔楼的施工测量质量,也可为其它类似的高层建筑施工提供参考。  相似文献   

Application of FLAC3D in supporting engineering of deep foundation ditch     

Jianhui QIU  Xueda SONG  Yunzheng WANG  Yi ZHENG  Xi YANG 《世界地质(英文版)》2008,11(4)

Based on the design principles of economic rationality and safety, multiple-pivot pile anchorage approach was used as the supporting engineering of a tall building with a deep foundation ditch. The designs, such as anchor arm, single pile and the whole, were set up in accordance with the calculations of the internal force from the equivalent beam and Yamagata Kunio methods. Moreover, the rationality of the design was estimated using the stability checks. FLAC3D was used for calculating the accuracy of the design. Using FLAC3D to simulating ditch cutting and supporting processes can obtain the equivalent results as the theory analysis in the displacement of ditch surrounding wall, the stress field and stress distribution.  相似文献   

FHMIPv6中基于MLD的DAD检测研究     

谭婷  马航航 《中国海洋大学学报(自然科学版)》2008,(Z1)

HMIPv6作为MIPv6的1种改进技术被提出以解决宏移动和微移动之间的切换管理机制问题。但是所引入的RCoA和LCoA的重复地址检测过程占据了切换延时的绝大部分,严重影响了切换效率,鉴于此,该文提出了1种基于MLD机制的DAD检测方案,并在理论上描述了该算法的实现过程。NS-2仿真结果表明该方案优化了切换算法,提高了切换效率,改善了移动性管理。  相似文献   

应用MAPGIS制作地球化学图单元素异常图及综合异常图   总被引：1，自引：0，他引：1  

袁义生  刘应忠  罗明学  何彦南 《贵州地质》2007,24(2):156-160

利用MAPGIS离散数据网格化模型绘制地球化学图,通过四种不同的网格化方法效果对比,在元素含量分析数据极差相对较小时,采用Kring泛克立格法网格化模型绘制的地球化学图效果佳。分析数据极差相对较大时,采用距离幂函数反比加权网格化模型绘制的地球化学图效果较好。两种数据网格模型绘制的地球化学图均达到化探规范中对地球化学图的要求,因此提出了应用MAPGIS制作地球化学等含量线图,利用地球化学等含量线图的属性,绘制单元素异常图及综合异常图。  相似文献   

地图图形数字化中的坐标转换   总被引：10，自引：4，他引：6  

俞善贤 《气象》1998,24(12):37-38

讨论了气候应用专用数据库气温,降水,日照时数等常用气象资料进行质量检验的必要性,介绍了基本质量控制,时间一致性检验和空间质量控制的思路,方法和步骤。  相似文献   

CTL—88B型天气雷达数字天线控制系统电路分析及故障检修     

桑茂华 《气象科学》1998,18(3):278-287

尽管现代化的飞行器性能、机载设备、通讯导航技术得到高度发展,但气象条件仍然是影响飞行和造成飞行事故的重要因素。对低云和雷雨的探测更是航空气象保障的重要内容。本文作者就新建南京禄口国际机场装配的CTL－88B型天气雷达的无线控制系统布线分散、控制保护环节多、运行功率大、故障率相对较高的特点,对如何能快速检测、修理随机故障,确保安全飞行所需的气象探测信息,结合实际工作经验,总结分析了天控系统总体框图、电路检修原理图等。由此,可根据故障现象对电路进行原理分析,测量主要检测点的动、静态参数,诊断故障部件和种类,并提供了常规故障检测的例子,从而极大地提高了排除故障的准确性和时效性,为飞行气象保障工作赢得了时间。  相似文献