论自动化和智能化空间对地观测数据处理系统的建立     

李德仁 《遥感学报》1994,(1)

未来１０年遥感对地观测技术的发展使得遥感影像的获取将走向多种传感器、多分辨率、多谱段和多时相。各国计划发射的对地观测卫星将使我们能够同时获取大量的、不同分辨率的、多谱段的可见光、红外、微波辐射和侧视雷达的数据。从而构成用于全球变化研究、环境监测、资源调查、灾害防治的多层次遥感影像金字塔。为了能够及时地、充分地利用这些对地观测数据来回答地学研究和人类社会发展所面临时的问题，更好地发挥遥感为国民经济建设服务的巨大潜力，必须从技术上建立一个自动化和智能化的空间对地观测数据处理系统。鉴于目前应用滞后于发射，软件落后于硬件的现实情况，本文简要叙述建立自动化和智能化空间对地观测数据处理系统的必要性和可能性，分析建立该系统的主要目标和需解决的关键技术并希望国家集中各有关方面的人力和财力来共同攻关，以建立和完善我国的地球科学信息系统，提高综合研究与深入分析的现代化水平。  相似文献   

地理信息系统费用效益分析     

钟耳顺  周宁 《遥感学报》1994,(1)

在经济发展的推动下，地理信息系统技术的应用在我国迅速兴起，特别是在城市规划和土地管理等领域非常活跃。随着一些大型系统的筹备和建立，地理信息系统费用效益分析已显得十分重要，许多用户迫切需要这方面的资料并了解有关方法。费用效益分析是地理信息系统进行立项可行性研究和系统管理的一个基本内容，本文主要介绍国外这一领域的观点，总结和提出确定地理信息系统费用和效益的方法，并讨论有关经济分析技术，旨在推动这一工作的深入开展。  相似文献   

新形势下测绘保密工作的思考     

王跃峰  于祝文 《地理信息世界》2001,(4)

在《中华人民共和国测绘成果管理规定》及其相关的管理规定中 ,对基础测绘成果保密等级的划分、调整和解密都作了详细的规定。但是在新形势下 ,现行保密法规的对象发生了变化 ,传统的保密管理方式已不适用 ,因此 ,应在保守国家核心机密的前提下 ,重新审定各种地理信息产品的密级 ,最大限度地扩大流通服务范围 ,使地理信息能更多更好地为国民经济建设服务  相似文献   

Vulnerability of groundwater in Quaternary aquifers to organic contaminants: a case study in Wuhan City,China   总被引：5，自引：0，他引：5  

Yanxin Wang  Broder J. Merkel  Yilian Li  Hui Ye  Surong Fu  Dana Ihm 《Environmental Geology》2007,53(3):479-484

More than 30 organic contaminants were detected in shallow groundwaters at Wuhan, the largest city in central China. Seriously contaminated groundwaters were from densely populated, industrial and commercial areas. Abnormal concentrations were found in groundwater from Hankou, downtown Wuhan: trimethylbenzene up to 29 μg/L, tetramethylbenzene up to 866 μg/L, and trichloroethene up to 9.5 μg/L. Benzene, Toluene, Ethylene and Xylene (BTEX) contamination of groundwater is serious and widespread at Wuhan, ranging between 0.14 and 25.0 μg/L. Considering the hydrogeological conditions of most Chinese cities, DRAMIC, a modified version of the widely used DRASTIC model, was proposed by the authors for assessing vulnerability of groundwater to contamination. The factors D, R, A and I in DRAMIC model are the same as in DRASTIC. The factor topography is ignored. The factor soil media is substituted by a new factor aquifer thickness (M) and the factor hydraulic conductivity of the aquifer by a new factor impact of contaminant (C). The equation for determining the DRAMIC Index is: DRAMIC = 5D _R + 3R _R + 4A _R + 2M _R + 5I _R + 1C _R. The calculated DRAMIC Index can be used to identify areas that are more likely to be susceptible to groundwater contamination relative to each other. The higher the DRAMIC Index is, the greater the groundwater pollution potential. Applying DRAMIC, a GIS-based vulnerability map for Wuhan city was prepared. Interestingly, places such as downtown Hankou, where enhanced concentrations of BTEX have been detected, correspond quite well with those with higher DRAMIC ratings.  相似文献   

Effects of climate change on the groundwater system in the Grote-Nete catchment,Belgium     

S. T. Woldeamlak  O. Batelaan  F. De Smedt 《Hydrogeology Journal》2007,15(5):891-901

The effects of climate change on the groundwater systems in the Grote-Nete catchment, Belgium, covering an area of 525 km², is modeled using wet (greenhouse), cold or NATCC (North Atlantic Thermohaline Circulation Change) and dry climate scenarios. Low, central and high estimates of temperature changes are adopted for wet scenarios. Seasonal and annual water balance components including groundwater recharge are simulated using the WetSpass model, while mean annual groundwater elevations and discharge are simulated with a steady-state MODFLOW groundwater model. WetSpass results for the wet scenarios show that wet winters and drier summers are expected relative to the present situation. MODFLOW results for wet high scenario show groundwater levels increase by as much as 79 cm, which could affect the distribution and species richness of meadows. Results obtained for cold scenarios depict drier winters and wetter summers relative to the present. The dry scenarios predict dry conditions for the whole year. There is no recharge during the summer, which is mainly attributed to high evapotranspiration rates by forests and low precipitation. Average annual groundwater levels drop by 0.5 m, with maximum of 3.1 m on the eastern part of the Campine Plateau. This could endanger aquatic ecosystem, shrubs, and crop production.  相似文献   

Citizens as sensors: the world of volunteered geography   总被引：62，自引：0，他引：62  

Michael F. Goodchild 《GeoJournal》2007,69(4):211-221

In recent months there has been an explosion of interest in using the Web to create, assemble, and disseminate geographic information provided voluntarily by individuals. Sites such as Wikimapia and OpenStreetMap are empowering citizens to create a global patchwork of geographic information, while Google Earth and other virtual globes are encouraging volunteers to develop interesting applications using their own data. I review this phenomenon, and examine associated issues: what drives people to do this, how accurate are the results, will they threaten individual privacy, and how can they augment more conventional sources? I compare this new phenomenon to more traditional citizen science and the role of the amateur in geographic observation.  相似文献   

Spatial Analysis Techniques as Successful Mineral-Potential Mapping Tools for Orogenic Gold Deposits in the Northern Fennoscandian Shield,Finland   总被引：1，自引：0，他引：1  

Vesa Nykänen  V. Juhani Ojala 《Natural Resources Research》2007,16(2):85-92

Geoscientific Information Systems (GIS) provide tools to quantitatively analyze and integrate spatially referenced information from geological, geophysical, and geochemical surveys for decision-making processes. Excellent coverage of well-documented, precise and good quality data enables testing of variable exploration models in an efficient and cost effective way with GIS tools. Digital geoscientific data from the Geological Survey of Finland (GTK) are being used widely as spatial evidence in exploration targeting, that is ranking areas based on their exploration importance. In the last few years, spatial analysis techniques including weights-of-evidence, logistic regression, and fuzzy logic, have been increasingly used in GTK’s mineral exploration and geological mapping projects. Special emphasis has been put into the exploration for gold because of the excellent data coverage within the prospective volcanic belts and because of the increased activity in gold exploration in Finland during recent years. In this paper, we describe some successful case histories of using the weights-of-evidence method for the Au-potential mapping. These projects have shown that, by using spatial modeling techniques, exploration targets can be generated by quantitatively analyzing extensive amounts of data from various sources and to rank these target areas based on their exploration potential.  相似文献   

关于虚拟地理环境研究的几点思考   总被引：10，自引：0，他引：10  

林珲  徐丙立 《地理与地理信息科学》2007,23(2):1-7

该文主要回答了目前被频繁问及的有关虚拟地理环境的几个问题。重点阐述了虚拟地理环境的概念、发展现状及其基本理论、方法、关键技术与应用,以及与传统地理信息系统的区别。指出虚拟地理环境是在空间数据库和地理模型管理基础上构建的、同时表达地理静态和模拟动态现象的、面向多用户的分布式协同虚拟环境。因此,虚拟地理环境突破地理信息系统以数据共享为核心的框架,走向以数据库和模型库为双核心的知识共享平台,进而形成一个新知识的生成环境。  相似文献   

中国区域地理、地形因子对降水分布影响的估算和分析   总被引：9，自引：1，他引：9       下载免费PDF全文

舒守娟  王元  熊安元 《地球物理学报》2007,50(6):1703-1712

不同与以往基于最小二乘的多元线性回归方法，本文首次尝试将新型的第二代回归分析方法——偏最小二乘回归分析方法应用到中国区域的降水建模中．利用区域内394个气象观测站建站到2000年45年(及以上)的降水资料，建立了一个简单的年、季降水量和地理、地形因子(包括纬度、经度、地形高程、坡度、坡向和遮蔽度)的关系模型，估算了区域降水量中地理、地形的影响部分，并分析了这种影响的特征．结果表明，用此方法建立的模型能够解释70%以上的因变量的变异，相关系数基本都在0.84以上，经交叉有效性检验，模型的回归效果较显著．分析表明，在多元线性回归不适用的情况下，本文基于偏最小二乘法的简单模型能够比较准确地定性、定量地再现实际降水分布．  相似文献   

GIS空间数据不确定性与质量控制的研究现状   总被引：28，自引：1，他引：28  

刘大杰  刘春 《测绘工程》2001,10(1):6-10

GIS空间数据不确定性和质量控制的研究是GIS基础理论问题研究中的一个重要内容。文中具体介绍了对该问题研究的几个阶段，对目前这一理论问题的研究现状作了简要介绍，并对GIS数据质量控制的策略提出一些看法。  相似文献