检索结果-南通市图书馆

^(14)C dating of moss peat banks in Fildes Peninsula, Antarctica

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第19期44卷 1817-1819页

作者： ZHAO Ye and li RongquanDepartment of resource and Environmental Sciences , beijing normal university., beijing 100875 , China Department of resource and Environmental Sciences Beijing Normal University Beijing China

Based on the radiocarbon data of the moss peat banks in Fildes Peninsula, Antarctica, it was calculated that the mean rates of peat accumulation in the upper layer and the lower layer are 0.195 and 0.069 4 mm·a-1 respectively. Based on the radiocarbon date (3 265 ± 120 aBP) and the mean rate of peat accumulation in the lower peat layer, it was calculated that

关键词： Antarctica moss peat bank 14C dating environmental change.

APPROACH TO THE REGIONAliZATION OF A GRICULTURAL-PASTURAliZATION AROUND CHANGSHAN ISLANDS IN NORTHERN YELLOW SEA

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2002年第3期12卷 218-225页

作者： ZHANG Yao-guang,DONG li-jing,li Chun-ping(institute of Marine resource,liaon ing normal university.Dalian 116029,P.R.China) institute of Marine resource Liaoning Normal University Dalian P. R. China

Based on the data of resources,environment and foundation of productio n,applying principal compo-nents-clustering quantitative analysis,this article divides the maritime space of Changshan Islands into three regions of agricultural-pasturalization,pr oviding a scientific basis for the ra tional distribution of marine culti *** three re-gions are as follows:1)The region of an agricultural-pastu ralization in the northern part of ma ritime *** includes Da Wangjia and Shicheng *** ma in production is cultivation of praw n and molluscs in sea beach,float raft culture of mussel in shallow sea and scallop,and breeding of sea cucumber in subma rine.2)The region of agricultur-al-pasturalization in the middle we stern part of maritime *** includes Da Changshan and Guanglu island s,and west-ern part of Xiao Chengshan *** main production is float raft cultu re of mussel and scallop in shallow se a,and breed-ing of sea cucumber in submarine.3)The region of agricultural-pastura lization of the southeastern part of maritime *** includes the eastern part of Xiao ChangShan Island,Haiyang and Zhangzi *** main production is bre eding of abalone,sea cucumber,algaes and fish.

关键词： Changshan Islands agricultural-pasturalization of seash ore principal compo-nents-clustering analysis region alization

Using remote sensing to research beijing wetlands dynamics

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第Z2期49卷 97-107页

作者： ZHAO Wenji, GONG Zhaoning, GONG Huili, li Xiaojuan, ZHANG Songmei & li Jing Key Lab of resource Environment and GIS of beijing, Capital normal university. beijing 100037, China Northeast institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China College of resources Science and Technology, beijing normal university. beijing 100875, China Capital normal Univ Key Lab Resource Environm Beijing 100037 Peoples R China Capital normal Univ GIS Beijing Beijing 100037 Peoples R China Chinese Acad Sci NE Inst Geog & Agroecol Changchun 130012 Peoples R China beijing normal Univ Coll Resources Sci & Technol Beijing 100875 Peoples R China

In beijing, where wetlands are important to municipal freshwater conservation and biodiversity retention, three different types of wetlands were identified: riverside wetlands, wetlands surrounding lakes and reservoirs, and wetlands in municipal *** sensing technology was applied in combination with field investigations to monitor and analyze the changes in these wetlands, and a combination of fusion technologies,Landsat TM/ETM+ and IKONOS imaging, was used to investigate and map them. This study indicates that not only have wetland areas been reduced by half, but also their ecological environments have been degraded because of rapid economic development and population increase. Suggestions based on this research are made to reconstruct the ecological environment of the wetlands and return them to their previous state.

关键词： beijing, wetland resource, remote sensing technology, ecological environment, dynamics.

Ontology-based analysis of multi-scale modeling of geographical features

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第Z2期49卷 121-131页

作者： WANG Yanhui, li Xiaojuan & GONG Huili Key Laboratory of Three-Dimensional Information Acquisition and Application, Ministry of Education, Capital normal university. beijing 100037, China beijing Key Laboratory of resource Environment and GIS, Capital normal university. beijing 100037, China Capital normal Univ Minist Educ Key Lab Dimens Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China Capital normal Univ Beijing Key Lab Resource Environm Beijing 100037 Peoples R China Capital normal Univ GIS Beijing 100037 Peoples R China

As multi-scale databases based on scale series of map data are built, conceptual models are needed to define proper multi-scale representation formulas and to extract model entities and the relationships among them. However, the results of multi-scale conceptual abstraction schema may differ, according to which cognition, abstraction and application views are utilized, which presents an obvious obstacle to the reuse and sharing of spatial data. To facilitate the design of unified, common and objective abstract schema views for multi-scale spatial databases, this paper proposes an ontology-based analysis method for the multi-scale modeling of geographical features. It includes a three-layer ontology model, which serves as the framework for common multi-scale abstraction schema; an explanation of formulary abstractions accompanied by definitions of entities and their relationships at the same scale, as well as different scales,which are meant to provide strong feasibility, expansibility and speciality functions; and a case in point involving multi-scale representations of road features, to verify the method's feasibility.

关键词： multi-scale representation, ontology-based analysis, multi-scale data modeling, hierarchical ontology.

A technique on automatic land-use database reconstruction based on scanning land-use map

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第Z2期49卷 57-63页

作者： li Xiaojuan, GONG Huili, YIN lianwang, SUN Yonghua, YANG lingli & WANG Yanggang Key Laboratory of 3D Information Acquisition and Application, Ministry of Education, Capital normal university. beijing 100037, China Key Laboratory of resource Environment and GIS of beijing, Capital normal university. beijing 100037, China Capital normal Univ Minist Educ Key Lab D Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China Capital normal Univ Key Lab Resource Environm Beijing 100037 Peoples R China Capital normal Univ GIS Beijing Beijing 100037 Peoples R China

Although a land-cover database is very important to national land use including urban planning and land-use management, it is very laborious and time-consuming to build through digitization of paper land-use maps (1:10000) and data input by hand. Here we propose a new, high-level, automatic technique to build a land-use database, which has proved useful and practical in building a land-use database of Baotou City.

关键词： land-use map vectonzation automatic building of land-use database.

On multi-scale representations of geographic features

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2006年第Z2期49卷 39-47页

作者： WANG Yanhui, li Xiaojuan & GONG Huili Key Laboratory of 3D Information Acquisition and Application, MOE, Capital normal university. beijing 100037, China Key Lab Laboratory of resource Environment and GIS of beijing, Capital normal university. beijing 100037, China Capital normal Univ MOE Key Lab D Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China Capital normal Univ Key Lab Lab Resource Environm Beijing 100037 Peoples R China Capital normal Univ GIS Beijing Beijing 100037 Peoples R China

This paper contains a review of the development of research on multiple representations compiled from Geographic Information Systems (GIS), including data structure, formalization and storage, and intelligent zoom. A summary is also included of the problems of interconnectivity, consistency maintenance, dynamic query and coexisting updates, as well as a research review of multi-scale databases and related studies. Finally,research directions and foci are proposed for the future design and implementation of multi-scale GIS.

关键词： multi-scale representation, multi-scale database, interconnectivity, consistency maintenance.

Research on the damage of the Great Wall of Ming Dynasty in beijing by remote sensing

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2008年第S1期51卷 195-202页

作者： li XiaoJuan,GONG Huili,ZHANG Ou,ZHANG WeiGuang & SUN YongHua The Key Lab of 3D Information Acquisition and Application,MOE,the Key Lab of beijing resource Envi-ronment and GIS,and College of resource Environment & Tourism,Capital normal university.beijing 100037,China The Key Lab of 3D Information Acquisition and Application MOE the Key Lab of Beijing Resource Environment and GIS and College of Resource Environment & Tourism Capital Normal University

Using aerial photos and high resolution satellite images of the year of 2004,this paper establishes remote sensing interpretation marks of the Great Wall of Ming Dynasty's damaged levels. Based on field survey and remote sensing survey in 1984,we analyzed present situation and changing characteristics being of the Great Wall of Ming Dynasty in beijing. The results show that about 7.02% of the wall is well-preserved (about 25861 m); 31.5% of the wall is slightly or moderately dam-aged (about 115989 m); 61.5% of the wall is badly damaged (about 226379 m). This paper analyzes the dynamic change of the Great Wall of Ming Dynasty. It shows that the damaged situation of the Great Wall of Ming Dynasty in beijing is serious. From 1984 to 2004,the well-preserved wall is decreased by 33206 m (decreased by 56%); badly damaged wall increased by 51207 m (increased by 67%). Finally,this paper analyzes the influence factors of damaging Great Wall. The conclusion is as follows: The damaged Great Wall is generally near the roads and villages,small slope,and easily arriving land.

关键词： the Great Wall of Ming Dynasty remote sensing interpreting damage dynamic change spatial analysis

Synchronous estimation of DTM and fractional vegetation cover in forested area from airborne liDAR height and intensity data

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2008年第S2期51卷 176-187页

作者： BAO YunFei1,2,CAO ChunXiang1,ZHANG Hao1,CHEN ErXue3,HE QiSheng1,2,HUANG HuaBing1,li ZengYuan3,li XiaoWen1,4 & GONG Peng1 1 State Key Laboratory of Remote Sensing Science,jointly sponsored by the institute for Remote Sensing Applications of Chinese Academy of Sciences and beijing normal university.beijing 100101,China 2 Graduate university.of the Chinese Academy of Sciences,beijing 100049,China 3 institute of Forest resource Information Technique,the Chinese Academy of Forestry,beijing 100091,China 4 Research Center for Remote Sensing and GIS,Department of Geography and beijing Key Laboratory for Remote Sensing of Environment and Digital Sites,beijing normal university.beijing 100875,China State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China Graduate university.of the Chinese Academy of Sciences Beijing China institute of Forest resource Information Technique the Chinese Academy of Forestry Beijing China Research Center for Remote Sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Sites Beijing Normal University Beijing China

We proposed a method to separate ground points and vegetation points from discrete return,small footprint airborne laser scanner data,called skewness change *** method,which makes use of intensity of laser scanner data,is especially applicable in steep,and forested *** does not take slope of forested area into account,while other algorithms consider the change of slope in steep forested *** ground points and vegetation points can be used to estimate digital terrain model(DTM) and fractional vegetation cover,respectively.A few vegetation points which were classified into the ground points were removed as noise before the generation of *** method was tested in a test area of 10000 square meters.A liteMapper -5600 laser system was used and a flight was carried out over a ground of 700―800 *** this tested area,a total number of 1546 field measurement ground points were measured with a total station TOPCON GTS-602 and TOPCON GTS -7002 for validation of DTM and the mean error value is -18.5 cm and the RMSE(root mean square error) is ±20.9 cm.A data trap sizes of 4m in diameter from airborne laser scanner data was selected to compute vegetation fraction *** of fractional vegetation cover was carried out using 15 hemispherical photographs,which are georeferenced to centimeter accuracy by differential *** gap fraction was computed over a range of zenith angles 10° using the gap light analyzer(GLA) from each hemispherical *** R2 for the regression of fractional vegetation cover from these ALS data and the respective field measurements is *** this study presents a method for synchronous estimation of DTM and fractional vegetation cover in forested area from airborne liDAR height and intensity data.

关键词： liDAR intensity skewness synchronous DTM fractional vegetation cover

Parameter determination to calculate water environmental capacity in Zhangweinan Canal Sub-basin in China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第6期22卷 904-907页

作者： Yingxia li ,Ruzhi Qiu,Zhifeng Yang,Chunhui li,Jingshan Yu State Key Laboratory of Water Environment Simulation,School of Environment,beijing normal university.beijing,100875,China. State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 Chin

Zhangweinan canal sub-basin （ZWN） has the most serious water resource shortage and water pollution problems in north of China. To calculate the water environmental capacity in ZWN, determination methods for design flow rates and degradation coefficients were discussed in this study. Results showed that 90% and 50% hydrological guarantee flow rates were suitable to be the design flow rates for rainy and dry seasons, respectively. Degradation coefficients of CODMn and NH3-N were 0.25 day^-1 and 0.15 day^-1 for branch streams and 0.5 day^-1 and 0.25 day^-1 for mainstreams, respectively in ZWN. With one-dimensional water quality simulation model, water environmental capacities were calculated to be 82,139 tons/yr for CODMn and 2394 tons/yr for NH3-N in ZWN.

关键词： degradation coefficient design flow rate water environmental capacity Zhangweinan