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时间:2020-09-02
《中国历年平均房价教程文件.doc》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、日期全国平均房价人均月收入房价收入比20018747161.2220029507811.22200310458761.192004123510261.202005136811681.172006152013441.132007190016231.172008228019711.162009380021311.782010503424972.022011537729311.932012579132011.812013623734841.792014(1-3月)659538311.72水利水电工程专业英语——水文与水资源篇1.HydrologicalCycleandB
2、udget1.水文循环与预算Hydrologyisanearthscience.Itencompassestheoccurrence,distribution,movement,andpropertiesofthewatersoftheearthandtheirenvironmentalrelations.Closelyalliedfieldsincludegeology,climatology,meteorologyandoceanography.水文学是一门地球科学。它包含地球水资源的发生、分布、运动和特质,以及其环境关系。与之密切相关领域包括地质学,气候学,
3、气象学和海洋学。Thehydrologiccycleisacontinuousprocessbywhichwateristransportedfromtheoceanstotheatmospheretothelandandbacktothesea.Manysub-cyclesexist.Theevaporationofinlandwateranditssubsequentprecipitationoverlandbeforereturningtotheoceanisoneexample.Thedrivingforcefortheglobalwatertranspo
4、rtsystemisprovidedbythesun,whichfurnishestheenergyrequiredforevaporation.Notethatthewaterqualityalsochangesduringpassagethroughthecycle;forexample,seawaterisconvertedtofreshwaterthroughevaporation.水文循环是一个连续的过程,在这个过程中水从海洋被运输到大气中,降落到陆地,然后回到海洋。有很多子循环存在。内陆水域的蒸发机器后在回到海洋前在陆地上的将于就是一个例子。全球水运输
5、系统的运行动力由太阳提供,通过蒸发这个过程赋予水运动能量。需要注意的是,水质在水循环通道中也会改变,比如,海水在蒸发后就会转变成淡水。Thecompletewatercycleisglobalinnature.Worldwaterproblemsrequirestudiesonregional,national,international,continental,andglobalscales.Practicalsignificanceofthefactthatthetotalsupplyoffreshwateravailabletotheearthislimit
6、edandverysmallcomparedwiththesaltwatercontentoftheoceanshasreceivedlittleattention.Thuswatersflowinginonecountrycannotbeavailableatthesametimeforuseinotherregionsoftheworld.Modernhydrologistsareobligatedtocopewithproblemsrequiringdefinitioninvaryingscalesofsignificantorderofmagnituded
7、ifference.Inaddition,developingtechniquestocontrolweathermustreceivecarefulattention,sinceclimatologicalchangesinoneareacanprofoundlyaffectthehydrologyandthereforethewaterresourcesofotherregions.完整的水循环在自然界中是全球性的。世界水问题需要在区域,国家,国际,洲际和全球范围的研究。地球上可利用的淡水总量与海洋中的咸水相比是有限的,并且非常少,这个重要的显示尚未得到人们足
8、够关注。因
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