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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   

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

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

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

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

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

8.
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   

9.
.Introducti0nTheNandujianghiver,withalengthOf3llkIn,adrainageareaof684lkm2andanaverageannunldischargOf60xl09m',isthelargstriveronHainanIsland.IttransportsanaveragannualsedimentloadOfO.68xlO6tonsnorthwdintoQangrhouStrait,wherethetidalrangnisca1.Om,andwavesandlongrhorecurrentsarerelativelystrong.TheNandujiangdeltacoves20OkIn2.ThedePOsitionalSystemOfthedeltaconsistsofrivermouthbars,distribotarymouthbars,marshdepositsfOrmedinbaysandlagoons,sandridges,sandsPitsanddunes.ThedistributionPatt…  相似文献   

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

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The regional characteristics of dust events in China has been mainly studied by using the data of dust storm, wind-blown sand and floating dust from 338 observation stations through China from 1954 to 2000. The results of this study are as follows: (1) In China, there are two high frequent areas of dust events, one is located in the area of Minfeng and Hotan in the South Xinjiang Basin, the other is situated in the area of Minqin and Jilantai in the Hexi Region. Furthermore, the spatial distributions of the various types of dust events are different. The dust storms mainly occur in the arid and semiarid areas covering the deserts and the areas undergoing desertification in northern China. Wind-blown sand and floating-dust not only occur in the areas where dust storms occur, but also extend to the neighboring areas. The range of wind-blown sand extends northeastward and southeastward, but floating-dust mainly extends southeastward to the low-latitude region such as the East China Plain and the area of the middle and lower reaches of the Yangtze River. Compared with wind-blown sand, the floating-dust seldom occurs in the high latitude areas such as North Xinjiang and Northeast China. (2) The affected areas of dust storms can be divided into seven sub-regions, that is, North Xinjiang Region, South Xinjiang Region, Hexi Region, Qaidam Basin Region, Hetao Region, Northeastern China Region and Qinghai-Xizang (Tibet) Region. The area of the most frequent occurrence of dust storms and floating-dust is in South Xinjiang Region, and of wind-blown sand in the Hexi Region. In general, the frequency of dust events in all the seven regions shows a decreasing tendency from 1954 to 2000, but there are certain differences between various dust events in different regions. The maximum interannual change and variance of dust events during this time happened in South Xinjiang Region and Hexi Region. The dust events generally occur most frequently in April in most parts of China. The spring occurred days of dust events occupied 60-70% of the whole year in Hetao Region and Northeastern China Region. However, in South Xinjiang Region and North Xinjiang Region, which was less affected by monsoon climate, dust events may occur at any time of the year, less than 50% of the events in this region occur during spring. In the remaining three regions 50-60% of the dust events occur in spring of a year.  相似文献   

12.
中国沙尘天气的区域特征   总被引:98,自引:0,他引:98  
利用筛选的1954~2000年中国338个站沙尘天气资料及相关气候资料,从沙尘天气区划方面着重分析研究了我国沙尘天气的区域特征。结果表明: 1) 我国沙尘天气多发区分别位于以民丰至和田为中心的南疆盆地和以民勤至吉兰泰为中心的河西地区。不同类型沙尘天气的空间分布范围不尽相同,其中沙尘暴主要发生在与北方沙漠及沙漠化土地相联系的极干旱、干旱和半干旱区内。扬沙和浮尘天气除了在沙尘暴发生区的绝大部分地区出现外,还向其它邻近地区扩展,如扬沙可向东北地区和东南的黄淮海平原及以南地区扩展;而浮尘天气则主要向东南方向扩展,可涉及整个黄淮海平原和长江中下游地区。相比之下,上风方向的中高纬地区,如北疆和东北北部地区,浮尘天气发生甚少。2) 全国沙尘暴天气易发区可划分为北疆、南疆、河西、柴达木盆地、河套、东北和青藏等7个亚区。沙尘暴和浮尘在南疆区发生日数最多,而扬沙在河西区发生日数最多。  相似文献   

13.
我国北方春季沙尘暴与气候因子之关系   总被引:22,自引:17,他引:5  
利用我国北方1954—2005年470个站点的春季沙尘暴资料和相应的气候资料,在合理区划沙尘暴易发地区的基础上,采用气象统计分析中的相关分析方法,对沙尘暴与气温、降水量、相对湿度、地温、风速、风蚀指数等气候因子间的相关性进行了统计分析,研究各个区域沙尘暴发生的气候特征,并提出了春季沙尘暴多发的简单气候概念模型。结果表明:①气候要素与我国北方春季沙尘暴的发生有一定的耦合关系,南疆的沙尘暴与气候要素的相关性最好,而北疆的最差。与沙尘暴相关性最好的气候因子是风速,其次是风蚀指数。②我国北方春季沙尘暴多发的简单的气候概念模型:前期(前冬),北、南疆地区较常年多干冷的西北气流;青藏东南地区和柴达木地区多暖湿的西南气流;河西地区、河套地区和东北地区为冷湿的偏西气流偏多。同期(春季),北、南疆地区较往年干燥且多大风;青藏东南地区和柴达木地区暖干;河西地区、河套地区和东北地区冷且多大风。  相似文献   

14.
使用天气学检验方法,对中国气象局兰州干旱气象研究所目前使用的GRAPES-SDM沙尘暴预报业务模式在2008-2011年春季沙尘天气预报情况进行检验评估。结果表明:①自2008年以来,GRAPES-SDM沙尘暴模式对中国北方区域沙尘天气的模拟预报能力较好,TS评分和预报效率保持较高的水平;②模式对内蒙古地区、河套地区及甘肃河西地区的预报效果最好,但常有空报或预报沙尘强度偏强的现象;模式能预报出南疆盆地的沙尘天气,但常有预报范围偏小、强度偏弱的现象;对青海地区的沙尘天气常有漏报现象;③模式对沙尘暴频发地区的预报效果较好,对沙尘天气偶发地区容易漏报,模式对新疆东部、内蒙古中西部地区空报较多;④模式对大范围沙尘天气过程的预报能力较好,对零星沙尘天气预报能力较差。通过检验,我们还提出了改进和完善GRAPES-SDM沙尘暴预报系统的一些建议。  相似文献   

15.
基于RS和GIS的河西走廊风沙灾害风险评估   总被引:1,自引:1,他引:0  
河西走廊位于中国西北干旱、半干旱区,受到周边沙漠和戈壁的影响,风沙灾害问题比较严重。依据灾害系统理论,从致灾因子危险性、孕灾环境脆弱性和承灾体易损性3个方面构建区域灾害风险评估体系和评估模型,对河西走廊风沙灾害风险进行评估。结果表明:(1)高风险地区主要分布在河西走廊内部的沙漠区,如酒泉市、玉门市、金塔县、高台县、临泽县以及武威市的北部地区,约占总面积的10.8%;(2)较高风险的地区主要分布在敦煌市、阿克塞哈萨克族自治县和河西走廊的北部,约占总面积的56.5%;(3)低风险地区位于河西走廊的东南部,该区在祁连山的天然屏障下,植被盖度高,雨水丰富;(4)作为风沙灾害的主体和对象,河西走廊的社会经济因素对风沙灾害风险的贡献率较低。而作为风沙灾害的物质基础和动力条件,沙源和风速仍是河西走廊风沙灾害风险的主要诱因;(5)经济发达城市在风沙灾害中具有更高的易损性,应该对城市邻近沙源进行重点防治。  相似文献   

16.
段海霞  郭铌  霍文  秦贺  马玉芬 《中国沙漠》2014,34(6):1617-1623
GRAPES-SDM沙尘模式和卫星遥感监测是目前沙尘暴监测预报业务中重要的工具.本文使用天气学检验方法,对中国气象局兰州干旱气象研究所目前使用的GRAPES-SDM沙尘模式2012年春季沙尘天气预报情况以及FY-2D卫星遥感产品沙尘指数IDDI的监测效果进行检验评估.结果表明:沙尘模式在西北沙尘暴预报业务中具有很好的预报参考价值,卫星遥感沙尘指数也具有较好的监测效果,但两者均存在一定的问题.沙尘模式对大范围沙尘暴过程有较好的预报能力,但对沙尘强度预报偏强;卫星遥感沙尘指数虽然不能定性地表示沙尘强度,但是在一定程度上能够反映沙尘强度的变化,不过反映沙尘强度的数值及其分布区间还有待于进一步完善.卫星遥感在南疆盆地常会将大片深厚的沙尘气溶胶区域误判为云区,造成对沙尘天气特别是沙尘暴天气未能识别的现象,另外IDDI指数不能用于夜间沙尘监测.  相似文献   

17.
新疆沙尘天气的演化特征及影响因子   总被引:5,自引:6,他引:5  
马禹  王旭  黄镇  陈春艳 《干旱区地理》2006,29(2):178-185
利用1961-2003年新疆90个气象站地面观测资料,分析了新疆沙尘天气的空间分布特征及演变规律,并构建多元线性回归沙尘因子模型,探讨了气温、气温日较差、气压、平均风速、降水量对沙尘天气的影响程度.新疆沙尘天气的高发区在塔克拉玛干沙漠及南缘,年沙尘日数南疆是北疆的7倍.沙尘天气的高发时段在3~9月,43年内呈明显递减趋势.北疆、南疆沙尘天气的历史演变有着较好的10~15年和8~10年的振荡周期.北疆沙尘天气的主要影响因子是平均风速和气温日较差、降水量,春季明显受气温和平均风速的影响,夏季主要受平均风速和气温日较差的影响.南疆平均风速和降水量的影响占主导地位,春季气温日较差的影响也比较显著.另外,南疆春季沙尘天气对日照时数有着显著的影响.  相似文献   

18.
早全新世石羊河流域沙尘暴活动记录   总被引:6,自引:3,他引:6  
施祺  陈发虎 《地理科学》2001,21(3):257-261
位于西北干旱区河西走廓东段石羊河流域尾闾地区湖泊沉积中记录到了多层快速风成沉积,通过剖面样品粒度、石英砂表面特征和磁化率、有机碳等多指标的分析表明为沙尘暴的堆积,推断在早全新世10000-6700aB.P.石头号河流域气候最湿润阶段仍存在周期性的沙尘暴活动。  相似文献   

19.
环渤海地区土地利用的时空变化分析   总被引:268,自引:13,他引:268  
根据1985和1995年2期TM影像资料,运用遥感影像机助解译方法、地理信息系统空间分析方法以及数理统计方法,全面分析了环渤海地区3省2市1985-1995年间分类土地利用的数量变化和空间变化特征,揭示了该区各类土地利用数量变化的幅度、速度和区域差异以及土地利用空间变化的主要类型、分布特征和区域方向,阐明了该区土地利用变化的区域特点,为土地可持续利用提供有效的决策支持。  相似文献   

20.
1 IntroductionSand-dust storms include both sand storms and dust storms[1]. When the visibility in local areas is greater than or equal to 50 m but less than 200 m, they are called severe sand-dust storms. When extremely severe sand-dust storm, the most severest type of sand-dust storm, occurs, the local instantaneous maximum wind speed can be greater than 25 m/s and a local visibility be less than 50 m or even descend to 0 m[2].Sand-dust storm is a critical environmental problem and is also a…  相似文献   

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