简介:在中国的沿海的沙丘岩石是由在地面上的条件下面的钙碳酸盐的eolian沙cemented,广泛地在华南的热带、副热带的海岸上散布。特别温度和降水以及本地波浪和地形条件为沙丘岩石的形成被要求。通讯被比较特征在Holocene环境变化和沿海的沙丘岩石开发之间发现海平面并且在有华南海岸上的沙丘岩石的年龄,规模,和硬化的Holocene时期的气候变化。调查结果在华南为在关于沿海的沙丘岩石的过去的研究未解决的一些问题提供很好扎根的解释:(1)因为在6000一BP前形成的沙丘岩石被在以后的时期升起了的海水盖住,没有有比在华南的6000年旧的年龄的沙丘岩石;(2)因为沿海的沙丘由于在Megathermal的结束以后掉落的温度在那时间在大规模上被堆积,有约3000一BP的年龄的沙丘岩石广泛地在今天的华南被发现;(3)中世纪的温暖的时期是为是进在华南的沿海的沙丘岩石的cemented的eolian沙丘的主要时期;(4)沙丘岩石缺乏比1000一BP年轻被说明为由气候调节在最近1000年不对硬化合适。
简介:Thispaperproposesamethodonanalyzingtheasynchronism-synchronismofprecipitationofdifferenthydrologicalregionsregardingtheS-to-NwatertransferareasofeasternChina.Thegeneralprocessoftheanalysisincludesthreesteps.Firstly,wecreatedtherainfallseriesoftheregionconcernedbycalculatingtheregionalaveragerainfallofthestationsintheareawiththehelpoftheclassicalThiessenPolygonmethod.Secondly,thestandardsofassessmentindicesforwetnessordrynessaresetaccordingtoGammadistributionfunctionwithacertainprobabilityP37.5%or62.5%givenrespectively.Finally,thefrequencyofninecombinationsarecountedasthequantitativefeatureofasynchronismandsynchronisminthreetimescales,thatistheyearly,seasonalandmonthlyscales.Theasynchronism-synchronismoftworegionpairshasbeenestimated.Theresultsshowthatthefrequencyofprecipitationasynchronismin1957-1998islargerthanthesynchronismfrequencyforboththeNorthChina-middleandlowerYangtzeRiverpairandfortheNorthChina-upperHanjiangRiverpair.Asforthesynchronismphenomena,thefrequencyofNd-Sdisratherlow.AsthecombinationsthataresuitableforwatertransfersareNd-Sw,Nn-Sw,Nd-SnandNn-Sn,thetotalfrequencyofthesecombinationsforNorthChina-middleandlowerYangtzeRiveris40%onanannualbasis,butonly28%inspringwhenwatershortagesaremostlikelytooccur.ThetotalfrequencyofthesecombinationsforNorthChina-upperHanjiangRiverisabout24%onanannualbasis,but35%inspringandwinter.Itshouldbenotedthatiffutureprecipitationpatternsaresimilartothatoftheperiod1957-1998,itisveryimportanttochangethenaturalcharacterofasynchronism-synchronismbyenhancingthecapabilityofhydro-projectsregulationandimprovingmanagementofthewatertransferproject.