老安山隧道洞内控制网的建立及其贯通精度     

辛金珠 《测绘通报》2018,(3):150-151,157

论述了利用双交叉导线测设长大隧道洞内控制网的方法。该方法能增强洞内导线网形的结构稳定性,提高隧道贯通的精度。  相似文献   

海域使用权立体分层设立若干问题探究          下载免费PDF全文

崔旺来  陈梦圆  贺义雄  钟海玥  李瑞发 《海洋开发与管理》2022,39(9):36-42

海域使用权立体分层设权是国家鼓励探索的一种用海新模式,海域空间的立体化开发利用已成必然趋势,但海域管理领域真正涉及海域使用权立体分层管理机制的系统性研究几乎没有。研究表明：国家是海域使用权立体分层设立的唯一主体;同一宗海区块空间已设定水体用海使用权可开发利用的海域空间边际外部分为客体范围;无偿划拨和有偿出让是两种常见设立方式;迭代升级行政审批程序应增加海域立体空间规划、创新空间管理体系,同时要考虑线性用海动态性;从登记客体、观测技术、登记制度、登记方法和登记内容5个维度改革创新权属登记模式;可通过研制海域使用权立体分层开发规划,赋予已设定海域使用权人优先权,支持相邻海域使用权人设立海域役权等方式协调与已设定海域使用权人权益。  相似文献   

陕西省GNSS连续观测系统建设与应用     

丁晓光  韩晓飞  苏利娜  张艺  张永奇 《防灾减灾学报》2013,(4):6-10

全球卫星导航定位系统（GNSS）的出现使得GPS连续运行参考站网络逐渐成为主流的形变监测手段。为了推进陕西地区构造环境变化规律的认识,兼顾大地测量、气象预报以及国民经济建设等方面,陕西省地震局组织建设了陕西省GNSS连续观测系统。本文介绍了陕西省GNSS连续观测系统的构成,对基准网、网络通信系统、数据中心等三个主要组成部分的具体架构进行了详细叙述,最后对GNSS连续数据在地震监测预报中的应用做了简要介绍,今后将把系统广泛应用于国土、测绘等相关行业。  相似文献   

‘WHY FAMILIES MOVE’: A RE-EXAMINATION     

《The Professional geographer》2013,65(2):124-129

Abstract

This study examines the role of surface geomorphic features in tree establishment at the alpine treeline in Glacier National Park, Montana, through the presentation of a multiscale, conceptual model of biogeomorphic relationships at alpine treeline. Empirical observations gathered through a multiscale field methodology over three summers serve as a base for the model. The model highlights the importance of surface geomorphic features, specifically boulders and terrace risers, in creating favorable local site conditions, largely by protecting seedlings from wind. The sheltering effect of surface features enables initial seedling establishment, and in some cases survival, above current treeline locations, thereby initiating a positive feedback effect that encourages subsequent tree establishment. Geomorphic features are therefore important in linking scales of pattern and process at the alpine treeline ecotone.  相似文献   

Populus nigra L. establishment and fluvial landform construction: biogeomorphic dynamics within a channelized river          下载免费PDF全文

Dov Corenblit  Johannes Steiger  Gaspard Charrier  José Darrozes  Virginia Garófano‐Gómez  Alexandre Garreau  Eduardo González  Angela M. Gurnell  Borbála Hortobágyi  Frédéric Julien  Luc Lambs  Sébastien Larrue  Thierry Otto  Erwan Roussel  Franck Vautier  Olivier Voldoire 《地球表面变化过程与地形》2016,41(9):1276-1292

Populations of the riparian pioneer species Populus nigra L. which establish on alluvial bars within river channels modulate sediment dynamics and fluvial landforms. Dense cohorts of P. nigra have colonized gravel point bars along the channelized River Garonne, France, during the last 20 years and have enhanced the vertical, lateral and longitudinal development of the bars. For this period, the geomorphic characteristics of two wooded point bars on this laterally stable river are closely linked to the spatial distribution and intensity of establishment and resistance of different cohorts of P. nigra. Furthermore, P. nigra colonization dynamics were controlled by engineer effects of this same species. This relationship is illustrated by a significant correlation between key geomorphic and biological variables measured in situ and characterized with a set of four aerial photographs taken between 2000 and 2010. The development of wooded point bars, which are discrete biogeomorphic units, over the studied period, appear to result from a specific biogeomorphic positive feedback of matter aggregation and vegetation establishment related to sediment trapping and stabilization by pioneer engineer plants. We propose a conceptual model of biogeomorphic unit construction for channelized, lateral stable rivers. We consider the resultant biogeomorphic units as functional from an ecological point of view because P. nigra enhances at the cohort scale (i) its own inherent capacity to resist hydrogeomorphic disturbances, and (ii) its resilience capacity as a result of successful colonization, especially downstream of mature poplar stands. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

东亚夏季风对山西省夏季降水的影响   总被引：1，自引：0，他引：1  

李智才  宋燕  武永利  王沛涛 《气候与环境研究》2010,15(6):797-807

利用NCEP1948～2007年逐日再分析资料、中国600站1960～2007年逐月降水资料和山西省1960～2007年65个测站的逐月、逐日降水资料,确立了850hPa112.5°E上候平均的假相当位温(θse)为340K和候平均的经向风为南风且南风风速≥2.5m·s-1等值线同时通过35°N的日期,将其作为山西省夏季风建立的时间,以θse≥340K的持续候数与平均持续候数相比的标准化值构造为东亚夏季风对山西省影响的强度指数I,可以较好地表征东亚季风区夏季风的强度和降水的空间分布,也可以较好地反映山西省夏季降水的强度和空间分布。该季风指数的年代际变化特征和线性趋势表明,自20世纪70年代以来东亚夏季风对山西省的影响有明显减弱的趋势,并且在1967年季风指数突变性地由强变弱。对山西省夏季风的建立和撤退时间的分析表明,近60年来东亚夏季风对山西省的影响时间越来越短。最后,分析了强弱夏季风指数年大气环流场的异常特征。  相似文献   

现代城镇地籍数据库建设及相关问题研究   总被引：6，自引：1，他引：5  

刘昌勤  廉永海  侯刚栋 《测绘与空间地理信息》2008,31(4)

根据城镇地籍数据库建设的实际工作阐述了地籍数据库建设的一般过程和方法,分析了目前城镇地籍管理系统建设各环节和应用中存在的问题,并在此基础上对下一代城镇地籍管理系统中的功能设计和相关问题做了讨论,对地籍数据的长效应用和今后地籍系统的发展做了浅述.  相似文献   

T_BB资料揭示的亚澳季风区季节转换及亚洲夏季风建立的特征   总被引：2，自引：0，他引：2  

何金海  朱乾根  M. Murakami 《热带气象学报》1996,12(1):34-42

发展了一个用于台风路径预报的初始场人造台风方案。该方案除包含对称台风环流外,也考虑了非对称风的作用。使用双向移动套网格模式作的试验预报结果表明,初始场中引入人造台风后能明显提高径预报的水平。  相似文献   

T_BB DATA-REVEALED FEATURES OF ASIAN-AUSTRALIAN MONSOON SEASONAL TRANSITION AND ASIAN SUMMER MONSOOM ESTABLISHMENT     

何金海  朱乾根  M.Murakami 《热带气象学报(英文版)》1997,3(1):18-26

Based on T_BB data from Meteorological Institute Research of Japan, study is carried out of the features of seasonal transition of Asian-Australian monsoons and Asian summer monsoon establishment,indicating that the transition begins as early as in April, followed by abrupt change in May-June; the Asian summer monsoon situation is fully established in June. The winter convective center in Sumatra moved steadily northwestward across the "land bridge" of the maritime continent and the Indo-China Peninsula as time goes from winter to summer, thus giving rise to the change in large scale circulations that is responsible for the summer monsoon establishment over SE Asia and India; the South China Sea to the western Pacific summer monsoon onset bears a close relation to the active convection in the Indo China Peninsula and steady eastward retreat of the subtropical TBB high-value band,corresponding to the western Pacific subtropical high.  相似文献   

地质资料馆网站建设的途径及分析     

张红玥 《国土资源信息化》2008,(1):35-37,45

地质资料馆网站建设的意义重大,全国各省局地质资料馆网站建设的条件已经具备,阐述网站建设的基本程序。调查分析了省市级三个地质资料馆网站的建设基本情况,得出结论并提出建议。  相似文献