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  • 2009 Volume 11 Issue 4
    Published: 25 August 2009
      

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  • ARTICLES
    DENG Xiangzheng, SHAO Quanqin, LI Guosheng, FAN Jiangwen
    2009, 11(4): 406-412.
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    LUCC informatics system,LUCCIS,is a newly developed research field on the basis of integrating the classical methodology of physical geography and the new progresses in GIS technologies.As a research field focused on studies of temporal and spatial processes of LUCC,LUCCIS has developed rapidly in past decades in which some technical components have been improved greatly.LUCCIS focuses on material cycles and macro life processes of multiple scales on the land surface with supports from remote sensing,GIS,and data fusion technologies.In this paper,the progresses of those kernel methodologies,techniques as well as compositional research achievements in China are described in detail,which make it possible for the establishment of LUCCIS.Specifically,the development in the technologies of extraction and analyses of remote sensing information,the exploration of driving mechanism of LUCC over space and time dimensions,the simulation of the spatial-temporal process and pattern of LUCC,the evaluation of the macro-ecological effects of LUCC and the establishment of research information platform of LUCCIS are all promoting the development of LUCC studies in China.The domestic research trends indicates that the development of extraction and analytical technologies of remote sensing information,the case study of exploring driving mechanism of LUCC,the methodological innovation of simulating the temporal and spatial process of LUCC,and the more accurate description of macro-ecological effects of LUCC play important roles in the methodology framework of LUCCIS.Also,the construction of multi-source and temporal-spatial data platform and the realization of massive data availability and integration are all kernel components of the methodology framework of LUCCIS.We can expect that LUCCIS would play a more and more important role in promoting LUCC research activities at regional and global scales.
  • ARTICLES
    DONG Jinwei, XU Xinliang
    2009, 11(4): 413-420.
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    The paper took Chifeng City of Inner Mongolia,a typical agro-pastoral transitional zone,as an example to investigate land use change process from 1988 to 2000 based on three periods of land-use data(1988,1995,and 2000) which were acquired from interpretation of TM images.The Land Exploitation Degree,the Land Conversion Degree,the information entropy,and spatial conversion matrix were adopted for finding characteristics of land use change especially land cultivation from grassland and cropland abandonment for grassland in two stages.The results showed that:(1)Land reclamation and grassland decreasing were main land use change processes in the whole stage.The area of cultivated land increased by 2424.12km2,and grassland reduced by 1959.65km2;(2)Comparing the two periods,in the first stage from 1988 to 1995,the changes between cultivated land and grassland were acute,and reached 2040.50km2 and concentrated in the north of Aohan County,634.75km2 in the opposite direct from cropland to grassland.Unused land also was conversed into grassland with a large area in Kerqin County;in the other stage from 1995 to 2000,the land use change speed slowed down.And main changes were the conversion of grassland and forest into cultivated land.There was an area of 828.50km2 of grassland turning to be cultivated in Aohan County and the north of Linxi County;(3)The information entropy for land use structure in three periods were 1.290,1.301,and 1.304,respectively,showed that the order manner for land use system was in reduction.The study revealed the transitions of grassland cultivation and cropland abandonment from 1980 to 2000,and provided supports for accurate portrait of regional ecological security and human-environmental coupling system.
  • ARTICLES
    NIU Fangqu, GAN Guohui, CHENG Changxiu, JIAO Li
    2009, 11(4): 421-427.
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    GIS is now used in more and more fields.It is required that GIS should be equipped more function.People desire that the geo-data visualization should be with multi-angle,multi-point and multi-level.So GIS must be equipped with automatic data-generalization function.GIS relies on a rule database to realize automatic data generalization.In this paper we suggest that automatic data generalization is a process using a computer to process every database record according to the rules.Based on the production-rule method,this paper proposed a method named Rules Pre-stored to enable users to define application rule database.According to the method,a GIS application first builds a thematic rules database which includes all the rules with respect to a specific theme.The rules database is called the theme rules database.Different users of the theme could define their own special application rule database based on the theme rules database through the user interfaces.A demonstration was also given.To some extent,the self-defined rule database and the separation of code and rules were accomplished.The result shows that the research idea and technical route are feasible.
  • ARTICLES
    KUANG Wenhui, LIU Jiyuan, SHAO Quanqin, SUN Chaoyang
    2009, 11(4): 428-435.
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    This study identifies the process of urban expansion and building density since 1932 using a combine of technology of RS and GIS.Urban expansion characteristics,urban land change from different building densities and its driving mechanism are analyzed.The results indicate that Yuan dynasty symbolizes the important stage of the beginning of urban development and construction.But the basic configuration of Beijing City was formed in Ming and Qing dynasty.Beijing City grew at a slow rate before 1984,and then the city began the first fast expansion under the socialist market economy during 1984-1992.Due to the implementation of the most severe farmland protection policy to prevent overheated real estate swallowing farmland in China,the urban expansion rate slowed down during 1992-2000.Beijing City has the fastest expansion rate after 2000 as a result of global economy development,Beijing urban planning and the Olympic Games in 2008.Urban land area per person has been gradually rising since 1956.Beijing City grew with relative high-density compact mode before 1984.But urban expansion indicates low-density sprawl trends after 1984,especially with "pie-like" form along the 5th and the 6th ring roads.The process of urban expansion shows the significant events,population growth and economic development are the most driving factors,in which the significant event is more prominent one.Highway construction and relative low land price in urban fringe area are the most important factors to accelerate urban low-density sprawl.
  • ARTICLES
    SUN Xiaoyu, SU Fenzhen, LV Tingting, GAO Yi
    2009, 11(4): 436-441.
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    The landscape spatial patterns of land use were a long-term result of interaction between human beings and nature.The coastal zone of western Pearl River Estuary,which is one of the hot spots of socio-economic development in China,was taken as the study area in this paper.The land use maps for 1995,2000 and 2003 were obtained by the interpretation of remote sensing images.The changes of land use information were analyzed.The result shows,main changes were that the cultivated land decreased and forest,construction land,water areas increased to different degrees.Under the support of GIS,the landscape spatial patterns of land use in study area were also quantitatively analyzed by using landscape indices such as fractal dimension,isolation index,fragmentation index,and diversity index.Result shows that the four landscape indices increased from 1995 to 2003 because of strong human interventions.At last the paper investigated the driving mechanism of the changes and concluded that population growth,pursuing for more economy benefits,effects of government policies,and its location advantages were the four main driving forces.
  • ARTICLES
    SONG Jia, ZHU Yunqiang, WANG Juanle, LI Rui
    2009, 11(4): 442-451.
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    Geo-ontology is the key of geographic knowledge existed in human brain being rebuilt in computer.The geo-ontology has important significance to improve and support formalized expression of geographic knowledge in computer.The model of spatio-temporal geo-ontology is a set of specification of formalized instruction describing geographic spatio-temporal characteristics.And it is the reference and basis for building spatio-temporal geo-ontology.The framework of spatio-temporal geo-ontology model based Geography Markup Language(GML) and the theory of spatio-temporal reasoning is proposed.The method of building spatio-temporal geo-ontology model is studied.The spatial ontology model,which consists of feature model,geometry model and spatial relationship model,is implemented by OWL language.And the temporal model,which consists of time instant and time period,is illustrated as well.The feature model is the core of spatio-temporal geo-ontology;it is connected with geometry model,temporal model,and spatial relationship model by object property in OWL.An applied example"the ontology of administrative regionalization"is given based on the model in the end.In the section,region ontology based Class Feature in spatio-temporal geo-ontology is built and it can be the ancestor of all other kinds of geographic unit.Administrative region ontology inherits the region ontology and extends it.The spatio-temporal characteristics and administrative level characteristics of administrative region are demonstrated based on some object properties defined in the model of spatio-temporal geo-ontology.It is of instructive significance to build and share the instances of geo-ontology for different applied studies based on the model of geographic spatio-temporal ontology.
  • ARTICLES
    XU Zhigang, ZHUANG Dafang, YANG Lin
    2009, 11(4): 452-460.
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    Human activity is an important driving factor to development and evolvement of ecosystem.Quantitative assessment of human activity intensity is foundation to analysis influences of human activities on structure,process and service functions of ecosystem.An approach to constructing a regional quantitative model of human activity intensity was proposed in the article.Firstly,17 representative human activities indices such as population density,the entire society employees,output value of agriculture,investment in fixed assets,density of road,students' number in high school were selected and a set of human activity index system referring to social,economic,culture aspects was established.Then,the Analytical Hierarchy Process(AHP) method was employed to determine the weights of each human activity index and the weights of importance of social,economic,culture aspects.Finally,a weighted average model was used to quantify regional human activity intensity.The proposed method was applied in three study areas: Wuchuan County in China,Darhan in Mongolia,Zakamensky in Russia.After calculation,human activity exponents of the three study areas in 2000 were 0.78,0.54 and 0.16,respectively,which decreased from south to north.And regional human activity exponents of Wuchuan County in mid 1980s,1995 and 2000 were 0.37,0.50 and 0.78,respectively,indicating a trend of increase.According to analysis on gradient changing of human activity and natural environment of the three study areas and the process of development of Wuchuan's human activity,we can conclude that the method is highly effective in evaluating regional human activities intensity,which can serve as a technique for related researches.
  • ARTICLES
    LI Tao, CUI Jing, WANG Erqi, ZHONG Ershun
    2009, 11(4): 461-467.
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    The real world GIS describes is changing continuously,while traditional GIS can only describe it statically.However,GIS has greatly extended its application fields,most of which contain dynamic spatial information that should be managed by GIS.In order to effectively define and dynamically simulate spatial variation,OOB methods have been adopted to model core elements of spatial process,which is a modification and extension of traditional spatial data model.Meanwhile,several concepts such as dynamic graphic object model,spatial-temporal event model and event engine have been imported and realized based on SuperMap GIS component platform.Additionally,visual efficiency of dynamic spatial variation has been improved by reasonable resource arrangement,high effective spatial-temporal query and dynamic cache mechanism.Spatial variation simulation can be essentially concerned as the description of spatial object at different temporal status driven by a certain event.Common spatial variation has been modeled at bottom level to achieve event driven simulating mechanism,which simplifies the development of application level.The effect of spatial variation simulation has also been improved since the structural optimization of basic model level through event driven engine,event index and dynamic map cache mechanism.
  • ARTICLES
    ZHANG Jinlu, WANG Yingjie, YU Zhuoyuan, LI Hongsheng
    2009, 11(4): 468-474.
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    With the development of computer technologies,a time began with a crazy burst of electronic maps.The content of electronic maps includes not only the spatial location information,but also various kinds of knowledge acquired by knowledge mining.So the map symbol model should be adjusted to the new forms and new content of electronic maps as the map symbol is the language of maps.This paper summarized the issues of traditional map symbol model,then the principles to design the adaptive map symbol model based on the theories of adaptive geo-visualization system after analyzing the characteristics of a variety of forms and content of map,following which the tree adaptive map symbol model is built.The whole map symbol library is organized following the tree structure,in the nodes of which there is a symbol-collection,and the symbol object includes symbol-description,symbol-definition and geometric data.So the map symbol under the adaptive map symbol model becomes a exhaustive object who has its own properties,not only a block of graphics.Then the adaptive map symbol system based on the tree symbol model is designed and the interfaces of this module are designed to other modules of the adaptive geo-visualization system.At last,an adaptive map symbol editor was implemented using the"late binding"method,which realizes that the symbol can adjust its appearances to the feature it expresses.This prototype system implemented the symbol-definition and geometric data parts of the tree map symbol model.As the conclusion,the tree map symbol model can be adaptive to new forms and contents of maps.
  • ARTICLES
    XUE Cunjin, SU Fenzhen
    2009, 11(4): 475-481.
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    Lags of researches on spatio-temporal topologies have seriously restricted the spatio-temporal reasoning and analysis.In this paper,uncertainties of space and time are discussed firstly,and an upper and lower approximate sets in rough sets theories are adopted to represent uncertain spatio-temporal objects.Then according to uncertainties of space and time,4 kinds of spatio-temporal objects are induced,and 10 kinds of topological frameworks between them are addressed.And based on the point-set theories,the Egenhofer's spatial topologies and the Shuhong's temporal topologies,a uniform description frame of spatio-temporal topologies expanded from the 4-intersection model is given.Furthermore,conclusions that topologies between type(I) and type(I) is the most basic spatio-temporal topologies,and that topologies between type(Ⅳ) and type(Ⅳ) is the most complex ones,and that others can be inferred from them are drawn.Finally,in views of complexities of uncertain spatio-temporal topologies,a universal flow of them is presented.
  • ARTICLES
    GUO Tengyun, DONG Guanpeng
    2009, 11(4): 482-490.
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    The urban spatial compact ratios,economic efficiencies and their relationships of metropolises in China in 1990 and 2000 were investigated in depth using GIS tool,Data Envelopment Analysis(DEA)and Malmquist index models methodologies,which got some significant findings.The findings show:1)The urban spatial compact ratios of metropolises in China had changed in evidence during 1990 to 2000,and there were two kinds of trends,that is,the urban spatial compact ratios of a majority of metropolises in China were getting bigger and those of a minority of ones smaller;2)the number of metropolises with greater urban spatial compact ratios was getting larger,and that of those with smaller spatial compact ratios was getting larger,too.And the former is greater than the later;3)most of the urban efficiencies of metropolises were not DEA efficient,only some were DEA efficient;4)the urban efficiencies tended to increase(the average Malmquist indexes are all greater than one)during the period of 1990 to 2000,in which the changes of urban efficiencies,including pure technical and scale ones,were increasing weakly,the technical change and total factor productivity change were more evidently than those of the metropolitan efficiencies during the same period;5)the metropolitan spatial compact ratios had positively correlated with their efficiencies,that is,with the increase of the metropolitan spatial compact ratios the urban efficiencies were getting higher and higher,and with the change rates increase of the urban spatial compact ratios,the urban efficiencies change trends were become even more evident,and vice versa;6)there were no correlations between urban spatial compact ratio change rates and urban technical changes of metropolises in China during the same period.
  • ARTICLES
    HUANG Chong, LIU Gaohuan, ZHANG Hailong, SHAN Kai
    2009, 11(4): 491-497.
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    Since 1990's,a sharp decrease of water quantity and frequent discontinuous flow happened in the lower Yellow River caused by climate change and rapid increase of water consumption in the Yellow River basin.This leads to deficiency of suitable water needed by the ecological system of the estuarine wetlands.As a result,fresh water wetlands in the river mouth are diminishing and facing the danger of disappearance.There is a growing awareness that evaluating consequences of landscape dynamics on habitat conditions became a central issue in wetland management and protection in the Yellow River Delta.In this paper,landscape ecological approaches combined with RS and GIS techniques were used to study the spatial-temporal variations in landscape pattern change and its impact on biodiversity conservation in the Yellow River Delta.To do so,we first analyze the river mouth wetland landscape dynamics from 1992 when the Reserve was built to the present.Two landscape metrics are used for assessing the characteristics and fragmentation process in the river mouth wetlands.Then the Red-Crowned Crane is selected as an indicator species for evaluating the ecological effect and habitat suitability variations under different landscape processes.The research shows that landscape degradation and habitat fragmentations are major threats to biodiversity conservation in the Yellow River mouth wetlands.From 1992 to 1999,the reed marsh wetland decreased almost as much as 50 per cent.The southeast spit formed before 1996 has experienced much erosion,with large area of tidal flat disappeared.As a result,30 per cent of the red crowned crane habitat degraded.Since 2000,the wetland restoration project has greatly increased the area of reed marsh,tidal flat and water body.However,oil exploration has caused the landscape more fragmented,which resulted in only 12 per cent of the red crowned crane habitat getting some improvement.Understanding the process of landscape change is thus crucial for determination of the driving factors for species conservation in wetland and for elaboration of restoration plans.
  • ARTICLES
    WU Feng, ZHAN Jinyan, DENG Xiangzheng, SHI Nana
    2009, 11(4): 498-504.
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    Maintenance of a sustainable ecosystem services is critical for human future.Ecosystem services degradation,however,is a common phenomenon around the world which leads to poor ecosystem services.In order to protect ecosystem services,it needs to implement ecosystem services management within different functional zones.Methods for ecosystem services division are the key to generate and represent functional zones,and studies on zoning ecosystem services can guide regional eco-management.This paper introduces spatial fuzzy clustering analysis embedded in System for Identifying and Zoning Ecosystem Services(SIZES).SIZES contains four main modules:multi-level indicators of ecosystem services characterizing module,importance rank of ecosystem services generating module,the core ecosystem services spatially identifying module,and zoning boundary of ecosystem services delimitating module.This approach can iteratively generate ecological delimitation boundary after inputting influencing factors of the ecosystem services and the core ecosystem services is extracted using factor analysis and then the boundaries of the ecosystem services zones are delimitated.Application of SIZES approach in Xilingol League shows that six functional zones scientifically and rationally explain the ecosystem services,and the result provides valuable spatial and temporal decision-making information for ecosystem services management.
  • ARTICLES
    KAN Aike, WANG Xuben, WU Xu, LI Guoqing, YU Nian, GAO Zhiyong, WANG Liuyan
    2009, 11(4): 505-512.
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    It is of great significance to study on the scientific organization and integrated method of multi-source eco-environmental data in regional ecological environmental research.Taking Qomolangma National Nature Reserve in Tibet as a case study,this paper discusses the key issues related to data integration,such as data characteristics of typical plateau ecosystem,data classification and organization,data modeling,as well as data encoding and metadata,etc.We design a conceptual modeling framework of eco-environmental data integration firstly,then,provide a multi-dimensional description of the basic semantic structure,which concludes datasets hierarchy and organization,attributes encoding and metadata standards.Lastly,we construct the multi-source ecological environment database of Qomolangma Nature Reserve.Through CASE tool Microsoft Visio 2003 modeling and data pre-processing,we seamless integrate eco-environmental thematic information that stored in FGDB database.Combined with spatial cognition rules and stacking the semantic characteristics demonstrated by feature class,basic information extraction orientated data integration analysis can be completed,and new knowledge and laws can even be generated.Based on eco-environmental data organization and integration,the solution we designed for Qomolangma Nature Reserve can establish a preliminary suit of ecological information flow mapping mechanism of "data integration-information extraction-knowledge discovery",which provides the practical and reliable data infrastructure for regional eco-environmental research.
  • ARTICLES
    LIU Wenliang, SU Fenzhen, DU Yunyan
    2009, 11(4): 513-519.
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    With the exponential increase of marine remote sensing data and their retrieval productions,it has been an urgent requirement for marine information services to dynamic visual express,query and analyze the marine spatio-temporal process through the Web.Based on the analysis of the resent network visualization technologies for the massive data and the characteristics of spatio-temporal process of marine scalar field,this paper discusses the network visual expression for point process and polygon process of marine scalar field.A new method to realize the remote realization for the marine spatio-temporal process has been proposed here and a prototype system has been set up to visualize the sea surface temperature(SST)of Taiwan Strait through the Web.In this prototype system,some functions were accomplished,such as the value query in the whole process and the process curve drawing of any random point in the SST field,the visual analysis for the polygon process in the SST field.
  • ARTICLES
    CHEN Chuanbin, LU Feng, LI Huiguo, WANG Qinmin
    2009, 11(4): 520-525.
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    Optimizing traffic and providing real-time information have become important tasks for modern urban management and public services.Currently,quality of city road network service is still quite weak,which restricts both the balanced utilization of road network and the improvement of travel efficiency.Although the technical bottleneck of traffic information collecting and transferring have got broken through in recent years,the lack of real-time traffic information processing technologies however results in low efficiency in involved applications,such as vehicle navigation system,public travel information service platform,logistics system and other ones in Location Based Service(LBS)and Intelligent Transportation Systems(ITS).As one of important means to process city road network related information,information fusion has great influence on the service quality of city road network management and traveling information service in ITS,LBS,modern logistics,and emergence response applications.This paper discussed the information fusion technologies in detail for city road network management and traveling service,including the integration of linear reference systems and road spatial information,temporal and multilevel dynamic segmentation,multi-model transportation network building,and dynamic connectivity relationship processing,and evaluated the corresponding solutions respectively.
  • ARTICLES
    ZHANG Chun, CHEN Rongguo, CHENG Changxiu
    2009, 11(4): 526-534.
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    Spatial database standard plays an important role in design and implementation of spatial database.SFA SQL(Simple Feature Access-Part 2:SQL option) and SQL/MM Spatial(SQL Multimedia and Application Packages-Part 3:Spatial) have been widely adopted in many spatial databases and GIS software,because they stand for the trend of SQL standards in the future.This article described and analyzed the two standards,compared them from several aspects,therefore,provided reference in choosing the SQL standard for spatial database.Firstly,the article mainly focused on the Geometry object model and the feature table implementation schema of the two standards.Besides the Geometry object model,SFA SQL also defined the text object model,and the SQL/MM:Spatial also defined the direction and angle object model.The feature table implementation schema determined the feature storage model on database.SFA SQL described two sorts of implementation.One is implementations based a more classical SQL relational model using only the SQL predefined data types and the other is extending SQL with additional types for geometry.SQL/MM only described the implementation schema of extending SQL with additional types for geometry.The mechanism for extending the type system of an SQL implementation is through the definition of User Defined Types(UDT).Secondly,the article focused on the difference of the two standards and compared them from three aspects:(1) the SQL-implementation environment;(2) the Geometry object model;(3) the routines to support geometric behavior and query.SFA SQL can be implemented in the predefined data type SQL 92 environment and UDT environment.The SQL/MM:Spatial can only be implemented in UDT environment.SQL/MM defined geometry types using circular interpolation and linear interpolation and SFA SQL only using linear interpolation.The geometric routine type in SQL/MM is richer than SFA SQL and the definition is more specific.Finally,the article surveyed the standardization state of seven popular spatial database products,overviewed the application situation of the spatial database standards;predicted the trend of the application requirement.
  • ARTICLES
    ZHAO Zhiping, SHAO Quanqin, HUANG Lin1
    2009, 11(4): 535-540.
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    Based on the field investigation of forest damages caused by the Severe Snow and Ice Chaos of early 2008 in Jinggang-Jitai-Yushan Transect,Jiangxi Province,we obtained Geographic and ecologic information of 563 survey points.The day-by-day precipitation and daily average temperature from January to February of 6 meteorological sites in the study area from 2000 to 2008 were selected to analyze the characteristics of the Severe Snow and Ice Chaos of the South of China,2008.Under the influence of the Severe Snow and Ice Chaos,mean NDVI of the research area is 0.57.Of 58.2% of this area,the NDVI is above 0.55,and of 38.4% of this area,the NDVI is between 0.35~0.55.The NDVI of forests can keep in a high value by the influence of the Severe Snow and Ice Chaos.With techniques of remote sensing and GIS we classified the NDVI of each survey point by species,stand origin,storey age and the degree of breaking.The result shows that the mean NDVI of natural forest is higher than plantation and secondary forest in the degree of none-breaking,but it decreases in a larger range than plantation with increasing of the degree of breaking.The mean NDVI of half mature forest is not higher than young forest and mature forest in the degree of none-breaking;and the mean NDVI of young forest decreases in a larger range than half mature forest and mature forest with increasing of the degree of breaking.Mean NDVI of mixed wood,bamboo,Chinese fir and slash pine are higher than broadleaf forest and masson pine in the degree of none-breaking;and with increasing of the degree of breaking,mean NDVI of broadleaf forest declines very quickly,mean NDVI of masson pine,slash pine,Chinese fir,mixed wood decline quickly,and mixed coniferous forest and bamboo decline not so quickly.
  • ARTICLES
    WU Mingquan, NIU Zheng, QIAO Yuliang, WU Chaoyang
    2009, 11(4): 541-548.
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    Through a contrastive analysis between aerosol production (MOD04_L2) of the Moderate Resolution Imaging Spectroradiometer(MODIS) and measured surface aerosol data,we verified the feasibility of using MODIS aerosol production(MOD04_L2) in analysis of aerosol spatial-temporal distribution.Then,using two data sets of the MODIS aerosol production from 2001 to 2007,i.e.the optical thickness at 550nm(AOT550) and the ratio of optical depth of small mode versus effective optical depth(FM),with help of auxiliary climate data,aerosol characteristics,mechanism of aerosol change,and affections of wind speed,precipitation and temperature on aerosol were analyzed.Based on the model between AOT550 and FM,this paper discriminates the aerosol to four types: urban/industrial(hereafter UI),clean maritime(CM),desert dust(DD),and mixed types(MT),and analyzed the effects of wind speed,precipitation and temperature to total aerosol and different aerosol types.Results showed that,(1) effected by climate factors such as wind direction,temperature and precipitation,the AOT got the maximal value in May and the minimal value in November;(2) main AOT types of Beijing were desert dust aerosol (DD) and mixed types aerosol(MT);(3)main influencing AOT types of Beijing were desert dust aerosol (DD) and urban/industrial aerosol(UI).From 2001 to 2007,urban/industrial aerosol (UI) had an obvious increased affection caused by rapid increase of cars in Beijing.Desert dust aerosol (DD)had a downtrend matched with statistic data,whereas total aerosol and other two aerosol types were keeping steady.On the whole,the atmosphere environment of Beijing was keeping stable.
  • ARTICLES
    LIU Wenchao, DONG Jinwei
    2009, 11(4): 549-555,534.
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    Rapid economic development has happened in the east coast of China since the Reform and Opening-up,at the same time,following a remarkable expansion of construction land.It is significant for suitable and intensive land use to investigate expansion features of four kinds of construction land,i.e.urban area,towns,rural settlements,roads and industrial sites according to economic development of cities and villages.Based on the three times of vector data(1988,1995 and 2000),we acquired land use data in 2008 by supervised classification of TM images.Four times of land use data(1988,1995,2000 and 2008) were collected as data sources for land use change monitoring.And this paper analyzed the temporal and spatial characteristics of land expansion and its impact on cultivated land in Suzhou-Wuxi-Changzhou Region over the past 20 years.Main results showed that:(1) The overall expansion area of construction land from 1988 to 2008 reached 2 354.55km2,and the area of urban expansion was the largest,which was 1 257.26km2,accounted for a half of the total expansion area.The expansion areas of towns,rural settlements,industrial and transport land were 695.91,355.96 and 45.42km2,respectively;(2) Urban expansion occupied a great deal of the cultivated land.The conversed areas from cultivated land into construction land were different for the three periods,which were 262.36km2 in1995-2000,656.36km2 in 1988-1995,and 1343.56km2 in 2000-2008.Results from this paper could offer important bases for land-use planning and management decision making in urbanized regions in the east of China.