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Accrdingtothetertualresearchbyscholars,therehavebeenpatemcharts4o,oooyearsago.ThepotterymapsmadebytheBabyloniansthe26thcenturyB.C.havebeenwellpreservedtodayInChina,BaZhenandJiuDingaretheeariieStmaps.Atthattime,thepnmitivemeasunngtoolswereyardsticks,cords,dividersandrules.ThereisanaccoUntofmapin.theearlyZhouLi-DiGuan-T1lXun.Theterm"map"inEnglishisnotaptlyworded.asitmeansmap,skychartandStarchart.TheRussianword"Kapta"meansmap,piCtureandcard.ThemainmearungispiCtureandcard.Thispaperfocus…  相似文献   

3.
Inrecentyears,AIsenismcausedbyhighAscontentinenvironmenthasbeenincreasinglyreportedinJapan.USA,Chile,Argentine,Hungal'yandoillercountries.inChina,EndemicArsenismhasbeenfoundinTaitvapMiang,InnerMongoliaGedou.ShanksprovincesorautonomousregionsandarousedseriousconcernbyrelevantgovenunentSagenciesandscientistS.BecausehairisoneoftheorgansofAsdeposihonandexcrehoninhumanbody.soflairAscontentcanbesuccessfullyusedasindexesforevaluatingAsqualityinhumanbodyanditsenvirolunent.OurstudyonhumanairA…  相似文献   

4.
1StudyAreaCentralDistrictisthelargestdialectinBotSWana.Itcoversanareaof146531kin',whichisroughlyonequarterofBotswana.ThedistrictborderstheRepublicofSouthcocainthesouthandeast,andZimbabweinthenorth-east.ItalsobordersNorthEastDistricttotheeast.ThenorthernboundalofthedistrictissharedfaiththeChobeDistrictandNgdrilandDistrict.Inthet"estandthesouth-u'estaledistrictbordersNgndland.Ghanzi.KwenengandKgahengDistrictS.ThedistlictisdiyridedintofiveadlnjnistrahvesubdistrictsfBobirwa.Serowemalapy…  相似文献   

5.
WithanincreaseinatmosphencconcentrationofCO,andothergreenhousegases,thereisastrongpossibilityofglobalwarming.Suchclimaticchangecanhavenotablethesonhydrologyandwaterresources.ThspaperdealswiththeHanjiangRiverhydrologicalropmeandwaterresourcesresponsestothjschange.I.RtglonalBackground,Tl1eHanJiangRiver,withanareaofl59,2Ookm-,isthelargesttnbuturyinthemiddlereachesoftheYangtzefover.Itislocatedatsubtropicalmonsoonzone,withtemperateandhumidclimate.Theannualaveragetemperatureisl2-l6"C.Thehighes…  相似文献   

6.
LinChaowasborninJieyangCounty,GuangdongProvince,ChinaonApril13,1909.HewenttotheArtSchool,LingnanUniversityasastudentin1926,andmovedtotheDepartmentofPhilosophy,ZhongShanUniversityinthenextyear.Hestartedtostudygeographyandgeologyin1929.Anergraduationin1930,hebecameanassistantprofessorintheDepanmentofGeography,ZhongshanUniversity.During1934-38,hewasaguduatestUdentintheUniversityofLiverpool,EnglandandwasconferredthePh.D.ingeograPhy.AnerhisreturntoChina,hehadsuccessivelyheldthepostsofpr…  相似文献   

7.
1BasicConceptsandTypesofTrafficEconomicBelt(TEB)l.lBasicconceptsofTEBThestUdyonthespecialtopicofTEBs~dinthe1980s.However-nounifieddeceptionofTEBsofarhasbeengivenbecauseoftheshortableofstudyandthechrencesinviewingthesubjectatpresent.Tiledefinihongivenbyusistint1lietrafficeconomicbeltisakindofbelt-shapedregionaleconomicorganirahonalsystemti.ltichaggregatesindustry,populahoryresources.informationstot"n.inteffioxtl,ofpassengers,inteffiowofgoodsandsoon.TheghehcaltransportPassageisitSmainde…  相似文献   

8.
中国沙尘事件的区域特征   总被引:8,自引:0,他引:8  
AsevereduststormoccurredoverEastAsiainthemiddletendaysofApril1998.Afteroneweek,itsdustplumeaffectedthecontinentofNorthAmerica.Thisattractedtheattentionofmanyscientistsintherelatedcountriestoduststorms.InrecentyearsthenumberofduststormshasbeenincreasinginChina.Itisnotonlyanimportantsymptomofdesertificationfromslowerchangetofasterchange,butalsoareflectionofthesynthesisofenvironmentalstates,includingclimate,ecosystemandsoil,whicharealldeterioratingtosomedegrees.AccordingtothedefinitionofMeteo…  相似文献   

9.
Aerosol samples were collected at altitudes from 584 m a.s.l.to 3,804 m a.s.l.at seven sites of the eastern Tianshan.The occurrence,distribution,and possible sources of 47 trace metals—including alkali metals and alkali earth metals,transition metals,lanthanoids,and heavy metals—were investigated.It was found that four sampling sites(Shuinichang,1,691 m a.s.l.;Urumqi City,809 m a.s.l.;Fu Kang Station,584 m a.s.l.;and Bogeda Glacier No.4,3,613 m a.s.l.)were contaminated mainly by heavy metals.Other three high-altitude sites(Urumqi Glacier No.1,3,804 m a.s.l.;Wang Feng road-maintenance station,3,039 m a.s.l.;and Tianshan Glaciology Station,2,135 m a.s.l.)were not polluted.The aerosol particles were clustered into two dominant types:crust-originated particles and pollution-derived particles.Aerosols from UG1,WF,and TGS were characterized by crust-originated particles such as clay,plagioclase,dolomite,alkali feldspar,and biotite;while those from SNC,Urumqi,FK,and BG4 were characterized by high content of Cl-rich particles,S-rich particles,and soot.The backward-trajectories results indicated that air masses arriving at SNC,Urumqi,FK,and BG4 were identified as the more polluted source,when compared to the short-range air mass transport from the North to UGI and WF.Relatively lower altitude,as well as terrain blocking,might be another important reason for the gradient difference in pollution influence among these seven places in the Urumqi River Basin.  相似文献   

10.
1EvaluationofCurrentDevelopmentofContainerizedTrafficinLiaoningProvinceAtpresent.contajnerized~cbusinesshasalreadybeendevelopedinthefollowingfourPOrtcihesofLiaoningprovince--DalingYingkou.DandongandJdriou.In1995,Dalian,whichwasranked77mcontainertenninalamongtheworld's100contalnerizedharbors.becamethefourthlargeStcontainerizedtrAncharborinChin4justallerShan~.TianjinandQingdao.Theinternahonalcontainerized~cvolumeofYinkouHalborwas14078cpUin1995.Dandonghalborbeganitscontainerizedtrafficb…  相似文献   

11.
Yangtze Estuary Tidal Wetlands Geographic Information System (YETWGIS) is a comprehensive software system for environmental management and decision of Yangtze estuary tidal wetlands. Based on MapObjects components technology, Data Mining technology, mathematical modeling method and Visual Basic language, this software system has many functions such as displaying, editing, querying and searching, spatial statistics and analysis, thematic map compiling, and environmental quality evaluation. This paper firstly outlined the system structure, key techniques, and achieving methods of YETWGIS, and then, described the core modules (the thematic map compiling module and environmental quality evaluation model module) in detail. In addition, based on information entropy model, it thoroughly discussed the methods of environmental quality evaluation and indicators' weight calculation. Finally, by using YETWGIS, this paper analyzed the spatial distribution characteristics of Heavy Metal and Persistent Organic Pollutants (POPs) of the Yangtze estuary tidal wetlands in 2002, and evaluated the environmental quality of the Yangtze estuary tidal wetlands in 2003.  相似文献   

12.
长江口滨岸湿地环境信息系统的建立与应用   总被引:9,自引:0,他引:9  
长江口滨岸湿地环境信息系统 (Yangtze Estuary Tidal Wetland Environmental Information System,简称YETWEIS)是一个适用于长江口滨岸湿地环境管理与决策的软件系统。该系统基于MapObjects组件技术、数据挖掘技术和数学建模方法,以Visual Basic为开发平台,功能包括对长江口滨岸湿地环境信息的显示、编辑、查询检索、信息统计、空间分析、专题地图编制和环境质量评价等。本文首先介绍了YETWEIS的体系结构、实现技术和主要功能,然后重点对专题地图编制模块和环境质量评价模块的实现思想进行了阐述,同时对水体、沉积物、大气环境质量评价方法、污染因子权重确定方法、基于熵值法的环境质量综合评价方法进行了深入探讨,并利用YETWEIS分析了长江口滨岸湿地2002年重金属和持久性有机污染物的空间分布特征,并对长江口滨岸湿地2003年环境质量进行了系统评价。  相似文献   

13.
长江口滨岸湿地无机氮界面交换通量量算   总被引:1,自引:0,他引:1  
基于3年长江口滨岸湿地沉积物-水界面无机氮季节性交换通量连续实测数据,建立无机氮界面交换通量空间插值模型与量算模型,对无机氮界面交换通量季节性空间分布特征、滨岸湿地不同岸段无机氮季节性界面交换总通量量算等研究。结果表明:修正GIDS插值模型在无机氮界面交换通量空间插值预测过程中精度明显优于IDS方法,而略优于普通Kriging方法;长江口滨岸湿地沉积物-水界面无机氮交换通量空间分布在不同季节表现出复杂的空间分异特征;利用修正GIDS插值模型对长江口滨岸湿地无机氮交换通量进行空间插值过程中,为提高通量量算模型精度,应采用1.2'×1.2'的空间尺度为最佳;长江口滨岸湿地无机氮界面交换总通量量算表明,长江口滨岸湿地在春季向水体释放无机氮,是水体无机氮的释放源,释放量为1.33×104 t,夏季、秋季和冬季表现为净化水体中无机氮,是水体无机氮的吸收汇,分别净化无机氮量为4.36×104 t、6.81×104 t和2.24×104 t,全年总体表现为净化水体中无机氮,净化量为12.1×104 t;长江口多年水体中无机氮通量多项式拟合分析得出,2002~2004年3年长江口水体中无机氮通量平均值为52.6×104 t,滨岸湿地对长江口水体中无机氮的年均净化率达23.0%。  相似文献   

14.
A detailed analysis of suspended sediment concentration (SSC) variations over a year period is presented using the data from 8 stations in the Yangtze River estuary and its adjacent waters, together with a discussion of the hydrodynamic regimes of the estuary. Spatially, the SSC from Xuliujing downwards to Hangzhou Bay increases almost constantly, and the suspended sediment in the inner estuary shows higher concentration in summer than in winter, while in the outer estuary it shows higher concentration in winter than in summer, and the magnitude is greater in the outer estuary than in the inner estuary, greater in the Hangzhou Bay than in the Yangtze River estuary. The sediments discharged by the Yangtze River into the sea are resuspended by marine dynamics included tidal currents and wind waves. Temporally, the SSC shows a pronounced neap-spring tidal cycle and seasonal variations. Furthermore, through the analysis of dynamic mechanism, it is concluded that wave and tidal current are two predominant factors of sediment resuspension and control the distribution and changes of SSC, in which tidal currents control neap-spring tidal cycles, and wind waves control seasonal variations. The ratio between river discharge and marine dynamics controls spatial distribution of SSC.  相似文献   

15.
长江口水域悬沙浓度时空变化与泥沙再悬浮   总被引:4,自引:0,他引:4  
A detailed analysis of suspended sediment concentration (SSC) variations over a year period is presented using the data from 8 stations in the Yangtze River estuary and its adjacent waters, together with a discussion of the hydrodynamic regimes of the estuary. Spatially, the SSC from Xuliujing downwards to Hangzhou Bay increases almost constantly, and the suspended sediment in the inner estuary shows higher concentration in summer than in winter, while in the outer estuary it shows higher concentration in winter than in summer, and the magnitude is greater in the outer estuary than in the inner estuary, greater in the Hangzhou Bay than in the Yangtze River estuary. The sediments discharged by the Yangtze River into the sea are resuspended by marine dynamics included tidal currents and wind waves. Temporally, the SSC shows a pronounced neap-spring tidal cycle and seasonal variations. Furthermore, through the analysis of dynamic mechanism, it is concluded that wave and tidal current are two predominant factors of sediment resuspension and control the distribution and changes of SSC, in which tidal currents control neap-spring tidal cycles, and wind waves control seasonal variations. The ratio between river discharge and marine dynamics controls soatial distribution of SSC.  相似文献   

16.
3S技术在湿地研究中的应用   总被引:23,自引:5,他引:23  
湿地具有多种生态功能和经济与社会价值,是人类赖以生存和发展的自然资源宝库与生存环境。湿地研究已受到国际社会的高度重视,成为国际生态学与环境科学研究的热点问题之一。3S技术的发展为湿地研究提供了新的方法和强有力的技术支持。主要论述了3S技术在湿地资源调查、湿地动态变化监测、湿地景观变化分析、湿地制图、湿地资源管理等方面的应用概况;在此基础上概要论述了3S技术在湿地研究应用中存在的主要问题和解决方案;最后论述了3S技术在湿地研究应用中的发展前景。提出应加大3S技术集成的深度,加强3S技术在湿地生物多样性、湿地环境效益、湿地边界确定及湿地资源管理等研究中的应用,把对湿地资源信息的分析和处理提高到研究湿地空间的规划和决策层面上,为管理和合理利用湿地资源指引方向。  相似文献   

17.
长江口潮滩环境信息系统功能设计研究   总被引:2,自引:1,他引:1  
该文在对长江口潮滩环境信息系统研究紧迫性分析的基础上,总结了长江口潮滩环境信息系统实现的总体目标、技术路线,同时阐述基于组件技术实现长江口潮滩环境信息系统的总体思路。  相似文献   

18.
长江口水域悬沙浓度时空变化与泥沙再悬浮   总被引:29,自引:0,他引:29  
根据近年来长江河口及其邻近水域8个测站1年的表层悬沙浓度逐日观测资料,并结合水动力状况,对悬沙浓度的时空变化进行了分析。结果发现,长江口自徐六泾以下悬沙浓度不断增高,并呈现口内夏高冬低,而口外冬高夏低,且量值为口外大于口内,杭州湾大于长江口。表明长江入海泥沙在海洋动力作用下强烈再悬浮;悬沙浓度在时间上呈现明显的大小潮周期和季节性变化。进一步分析认为,海洋动力 (风浪和潮流) 是泥沙再悬浮的主导因素,制约悬沙浓度的年内变化,其中潮流控制悬沙浓度的大小潮周期变化,风浪引起悬沙浓度的季节性变化,河流径流和海洋动力的对比制约悬沙浓度的空间分布。  相似文献   

19.
Estuarine wetlands serve as a natural barrier to remove the land-generated pollutants and attenuate the pollutant load from the land to the sea.As one of the most important estuarine wetlands,the Yangtze estuarine wetlands have attracted particular interests in the biogeochemical studies of nutrients.The objectives of this study were to characterize the seasonal and spatial distribution of dissolved inorganic nitrogen(DIN) fluxes across the sediment-water interface;to calculate the total DIN fluxes in a year and different seasons;and to evaluate the DIN removing capability of the sediment in the tidal wetlands of the Yangtze Estuary.The spatial distribution of DIN fluxes shows complicated seasonal variations and spatial differences.The annual DIN fluxes range from-22.22 mmol N m-2 h-1 to 19.54 mmol N m-2 h-1,with an average of-1.48±1.34 mmol N m-2 h-1.The tidal wetlands in the Yangtze Estuary behave as a source of water DIN in spring when DIN is released from sediment into overlying water,and the released amount of DIN is 1.33×104 tons of nitrogen(T N).In summer,autumn and winter,the sediment absorbs the DIN from the overlying water,and the absorbed amounts of DIN are 4.36×104 T N,6.81×104 T N and 2.24×104 T N,respectively.The average amount of DIN in overlying water of the Yangtze Estuary is 52.6×104 T N yr-1,and the perennial average amount of DIN absorbed from the overlying water by the sediment is 12.1×104 T N yr-1.The annual DIN elimination rate of the tidal wetlands was 23.0%.  相似文献   

20.
银川平原湿地空间分布格局图谱   总被引:1,自引:0,他引:1  
采用湿地遥感制图方法,获取了银川平原湿地景观空间分布信息。在综合分析湿地分布图、地貌图、水系等图件的基础上,应用地学信息图谱分析方法,按照湿地水源补给状况建立了湿地空间分布格局图谱,并解释了银川平原湿地景观格局图谱的形成机理。  相似文献   

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