互联网地理信息系统的分布式超地图模型     

袁相儒  陈能成  龚健雅 《武汉大学学报(信息科学版)》2000,25(4):299-304

介绍了超地图的概念 ,提出了互联网地理信息系统的分布式超地图模型 ,并详细阐述了其定义 ,然后阐明超地图关系和操作。最后 ,结合InternetGIS—GeoSurfV 3 .0介绍了此模型的设计与实现  相似文献   

基于云计算的位置服务平台建设研究     

李振龙  徐剑平 《地理信息世界》2012,(1):69-71,79

云计算作为一种革命性的计算模型在很多行业都成为重要的技术趋势。将云计算应用于空间地理信息领域所形成的空间云计算也逐渐成为整个空间地理信息行业的主流技术。位置服务利用当今高速发展的互联网和多样化的移动终端向用户提供基于位置的信息和娱乐服务。空间信息数据是位置服务平台的重要组成部分,本文首先介绍云计算相关概念,根据对目前位置服务平台存在的问题的剖析提出了基于云计算的位置服务平台建设的思路和平台架构,最后分析了该平台的特点和所形成的产业链。  相似文献   

库玛拉克河流域盛夏最大可能融雪雪量估算     

傅华  贾丽红  肖继东  杨志华  李聪 《干旱区地理》2012,35(2):193-199

利用2002-2008年6~9月EOS/MODIS卫星晴空资料,计算分析了融雪期库玛拉克河流域的积雪面积、覆盖率、雪深及雪水量;利用气象、水文台站的观测资料,对2002-2008年积雪变化与气象因子间的相互关系,2002-2008年7次洪峰时间段内最高温度的有效作用时间和12 h降水的有效影响时间等进行了分析与研究。结果表明：2002-2008年盛夏库玛拉克河流域高温融雪的主导作用比较明显,当流域内山区积雪量在5.5×108 m3以上、0 ℃层平均高度上升到4 500 m以上并且能维持4 d,库玛拉克河流域融雪型洪水的融雪量可达1.8×108~10.3×108 m3,夏季0 ℃层高度的变化可作为融雪型洪水预测的较好指标。2002-2008年这个历史时期实际积雪融化后产生的雪水当量9.88×108 t,全部融化后产生的最大可能雪水当量小于11.18×108 t;这个历史时期理论最大可能积雪融化后产生的雪水当量为17.55×108 t,全部融化后产生的雪水当量小于17.75×108 t。估算实际融化和理论融化的雪水当量,可为积雪融化后产生的最大洪水量估算提供数据支持。  相似文献   

分布式水文模型的并行计算研究进展   总被引：3，自引：1，他引：2  

刘军志  朱阿兴  秦承志  陈腊娇  吴辉  江净超 《地理科学进展》2013,32(4):538-547

大流域、高分辨率、多过程耦合的分布式水文模拟计算量巨大,传统串行计算技术不能满足其对计算能力的需求,因此需要借助于并行计算的支持。本文首先从空间、时间和子过程三个角度对分布式水文模型的可并行性进行了分析,指出空间分解的方式是分布式水文模型并行计算的首选方式,并从空间分解的角度对水文子过程计算方法和分布式水文模型进行了分类。然后对分布式水文模型的并行计算研究现状进行了总结。其中,在空间分解方式的并行计算方面,现有研究大多以子流域作为并行计算的基本调度单元;在时间角度的并行计算方面,有学者对时空域双重离散的并行计算方法进行了初步研究。最后,从并行算法设计、流域系统综合模拟的并行计算框架和支持并行计算的高性能数据读写方法3个方面讨论了当前存在的关键问题和未来的发展方向。  相似文献   

西北地区山区融雪期气候变化对径流量的影响(英文)   总被引：5，自引：0，他引：5  

李宝富  陈亚宁  陈忠升  李卫红  张宝换 《地理学报(英文版)》2013,23(1):17-30

Water resources in the arid land of Northwest China mainly derive from snow and glacier melt water in mountainous areas. So the study on onset, cessation, length, tempera-ture and precipitation of snowmelt period is of great significance for allocating limited water resources reasonably and taking scientific water resources management measures. Using daily mean temperature and precipitation from 8 mountainous weather stations over the pe-riod 1960?2010 in the arid land of Northwest China, this paper analyzes climate change of snowmelt period and its spatial variations and explores the sensitivity of runoff to length, temperature and precipitation of snowmelt period. The results show that mean onset of snowmelt period has shifted 15.33 days earlier while mean ending date has moved 9.19 days later. Onset of snowmelt period in southern Tianshan Mountains moved 20.01 days earlier while that in northern Qilian Mountains moved only 10.16 days earlier. Mean precipitation and air temperature increased by 47.3 mm and 0.857℃ in the mountainous areas of Northwest China, respectively. The precipitation of snowmelt period increased the fastest, which is ob-served in southern Tianshan Mountains, up to 65 mm, and the precipitation and temperature in northern Kunlun Mountains increased the slowest, an increase of 25 mm and 0.617℃, respectively, while the temperature in northern Qilian Mountains increased the fastest, in-creasing by 1.05℃. The annual runoff is also sensitive to the variations of precipitation and temperature of snowmelt period, because variation of precipitation induces annual runoff change by 7.69% while change of snowmelt period temperature results in annual runoff change by 14.15%.  相似文献   

Performance evaluation of a distributed hybrid test framework to reproduce the collapse behavior of a structure     

Tao Wang  Maria Cortes‐Delgado 《地震工程与结构动力学》2012,41(2):295-313

A hybrid numerical and experimental simulation to collapse was conducted on a one‐half scale moment‐resisting frame building with two experimental substructures at different locations. An extensible hybrid test framework was used that adopts a generalized interface to encapsulate each numerical or tested substructure, through which only boundary displacements and forces are exchanged. Equilibrium and compatibility between substructures are enforced by an iterative quasi‐Newton procedure, while adopting a predictor‐and‐corrector method to avoid loading reversals on physically tested substructures. To overcome difficulties in controlling stiff axial and rotational deformations at the boundaries, the flexible test scheme employs either open‐loop or closed‐loop control at the boundaries: enforcing either compatibility or equilibrium, or both requirements at critical boundaries. The effectiveness of the extensible framework and its capability to simulate structural behavior through collapse is demonstrated by a geographically distributed test that reproduced the collapse behavior of a four‐story, two‐bay, steel moment frame previously tested on an earthquake simulator. A comparison of both experiments highlights the viability of the hybrid test as an effective tool for the performance evaluation of structural systems from the onset of damage through collapse. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

基于碳纤维加热光缆的砂性土渗流场C-DTS分布式监测试验研究   总被引：1，自引：0，他引：1  

严珺凡  施斌  曹鼎峰  魏广庆  朱鸿鹄 《岩土力学》2015,36(2):430-436

岩土体中渗流场的监测是岩土工程防灾减灾中一项必不可少的基础工作。在总结已有监测方法优缺点的基础上,提出了渗流场碳纤维加热光缆的分布式温度光纤感测技术（简称C-DTS）;介绍了该方法的监测原理;提出了温度特征值（ ）的概念;设计了砂性土渗流模拟装置,并对砂性土中不同渗流速率下的渗流场进行了室内试验。通过试验确定了 与渗流速率（V）之间存在线性关系;证明了碳纤维加热光缆能够有效地提高DTS监测的敏感性,可实现渗流速率的分布式监测。对该方法应用于工程实践还需要开展的研究工作进行了分析。  相似文献   

Uplift of deck or footings in bridges with distributed mass subjected to transverse earthquake          下载免费PDF全文

Michael N. Fardis 《地震工程与结构动力学》2015,44(15):2755-2773

The eigenvalue problem is analytically formulated in symmetric bridges with distributed mass and moment of inertia under transverse earthquake. The piers are elastically supported on the ground. The deck is monolithically connected to one or two piers for all degrees of freedom and restrained or transversely free at the abutments. The characteristic equation, symmetric normal modes, modal participation factors, and participating mass ratios are given analytically. The problem is expressed in terms of few dimensionless parameters: (i) the radius of gyration of the deck mass divided by the pier height; (ii) the ratio of the rotational stiffness of a footing to that of the pier at the base; (iii) the ratio of flexural stiffness of the outer spans to those of the pier; (iv) the ratio of torsional stiffness of side spans to the rotational stiffness of the pier top; (v) for two piers, the side‐to‐central‐span ratio. Modal response spectrum analysis gives the moment at the base of the footings and the torque in the deck at its supports on the abutments as ratios to the values at incipient uplifting from the ground or the bearings. The peak ground acceleration of the motion at the onset of either one of these two types of nonlinearity is depicted as a function of the dimensionless parameters and the fundamental period of an elastic deck supported only at the abutments, or of a rigid deck on piers fixed against rotation at top and bottom. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Testing the applicability of a kinematic wave-based distributed hydrological model in two climatically contrasting catchments     

T. Tanaka  Y. Tachikawa 《水文科学杂志》2015,60(7-8):1361-1373

Abstract

Steep mountainous areas account for 70% of all river catchments in Japan. To predict river discharge for the mountainous catchments, many studies have applied distributed hydrological models based on a kinematic wave approximation with surface and subsurface flow components (DHM-KWSS). These models reproduce observed river discharge of catchments in Japan well; however, the applicability of a DHM-KWSS to catchments with different geographical and climatic conditions has not been sufficiently examined. This research applied a DHM-KWSS to two river basins that have different climatic conditions from basins in Japan to examine the transferability of the DHM-KWSS model structure. Our results show that the DHM-KWSS model structure explained flow regimes for a wet river basin as well as a large flood event in an arid basin; however, it was unable to explain long-term flow regimes for the arid basin case study.  相似文献   

一种GNSS大网数据快速高效处理策略     

崔阳  吕志平  张友阳  陈正生  李林阳 《大地测量与地球动力学》2015,35(3):383-386

针对当前大型GNSS网络数据处理需求与现有处理策略和能力的矛盾,介绍基于不动点理论所建立的Ambizap网解新算法,将分布式计算技术引入到GNSS数据处理中,设计并利用.NET框架下的分布式技术实现分布式环境下基于Ambizap算法的大型GNSS网数据分布式处理流程,通过多个算例验证了Ambizap算法的精度和其分布式应用的高效性。  相似文献