简介:ThereasonsfortheYangtzeRiverfloodcalamityin1998arebrieflyintroduced.Theauthorsbelievethatusinga'soilreservoir'conceptisanimportantmeanstohelpcontrolfloodingoftheYangtzeRiver.A'soilreservoir'hasalargepotentialstoragecapacityanditswatercanberapidly'discharged'intotheundergroundwaterinatimelyfashion.Theeroded,infertilesoilsoftheYangtzeRiverWatershedarecurrentlyanobstacletoefficientoperationofthe'soilreservoir'.Thestoragecapacityofthis'soilreservoir'hasbeenseverelyhamperedduetointensivesoilerosionandtheformationofsoilcrusts.Therefore,possiblemeasurestocontrolfloodsintheYangtzeRiverWatershedinclude:rehabilitatingthevegetationtopreservesoilandwaterontheerodedinfertilesoils,enhancinginfiltrationofthedifferentsoiltypes,andutilizingthelarge'soilreservoir'oftheupperreachesoftheYangtzeRiver.
简介:在夏天,紧张,地点和vertical的不同汇编副热带的高度和早/以后的时间组织它的季节向北跳在中国上引起不同降水模式。因此,副热带的高活动和它的原因在在中国和Chinadrought/flood的原因上的极端气候的事件的出现期间被学习改进预报的天气。自从1990年代,副热带的高活动的物理机制上的许多理论研究被做了,它集中于加热的热带diabatic的效果并且在副热带的高形成和变化上的空间不一致的加热,但是很少考虑动态环境变化的影响在它上由西的系统或副热带的上面的喷气的反常活动产生了。根据动态理论和摘要的原则,此处,在2003的HuaiheRiverfloods上的副热带的高活动和它的影响被分析,并且在副热带的高活动和它的形成机制的西、副热带、热带的循环的反常特征的效果进一步被学习,它被期望对在中国的运作的夏天降雨预报有用。
简介:Aquasi-2Dunsteadyflowandsedimenttransportmodelsuitableforthesimulationoflargelowlandriversystems,includingtheirfloodplains,ispresented.Thewaterflowandsedimentequationsarediscretisedusinganinterconnectedirregularcellsscheme,inwhichdifferentsimplificationsofthe1DdeSaintVenantequationsareusedtodefinethedischargelawsbetweencells.Spatially-distributedtransportanddepositionoffinesedimentsthroughouttheriver-floodplainsystemaresimulated.Themodelisappliedovera208-kmreachoftheParanaRiverbetweenthecitiesofDiamanteandRamallo(Argentina)comprisingariver-floodplainareaof8100km~2.Aftercalibrationandvalidation,themodelisappliedtopredictwaterandsedimentdynamicsduringsyntheticallygeneratedextraordinaryfloodsof100,1000,and10,000yearsreturnperiod.Thepotentialimpactofa56-kmlongroadembankmentconstructedacrosstheentirefloodplainissimulatedandcomparedtomodelresultswithouttheembankment.Theembankmentresultsinincreasesinupstreamwaterlevels,inundationextent,flowduration,andsedimentdeposition.
简介:AsshownincomparisonandstudyoftheHIRS-Tb12dataandconventionaldata,temperature,humidityandverticalmotionarestructureddifferentlyintheSouthernandNorthernHemispheres,whicharewelldepictedwiththeHIRS-Tb12data.WhenhighpressuresrapidlydecreaseovertheregionsofSouthChinaSeaandArabianSeawiththeHIRS-Tb12lessthan200W/m2,monsoonswillsetoffintheSouthChinaSea,ArabianSeaandBayofBengal,respectively,Fromayearofsignificantdroughttooneofsignificantfloods,thetrendofevolutionissignificantlydifferentinthedowndraftareasofthesubtropicalhighsbetweenthetwohemispheres.
简介:以前的学习来到结论:基于南方亚洲人高度(SAH)的异例,在热带、副热带的区域上的100-hPageopotential高度,和100-hPa循环,我们能在长江山谷和诺思中国预言降水异例。测试它的有效性,一系列实验被设计了并且操作,它包括控制实验,敏感实验(它增加了异例进100-hPageopotential高度和风地),并且四合成的实验。基于象EPR-CF,EPRCD,EPR-HF,和EPR-HD那样的镇静的起始的领域试验,能在长江山谷和诺思中国复制洪水或干旱。它建议在热带、副热带的区域上的SAH,100-hPageopotential高度,和发行量的异例可以可能在二个区域暗示夏天降水异例。SAH,100-hPageopotential高度,和西南的异例流动在以前的时期的敏感实验结果表演是干旱或洪水的一个信号在长江山谷和诺思中国的下列夏天。并且它也是在二个区域在夏天降水异例上有影响的因素之一。100-hPageopotential高度并且SAH和西南流动的异常加强的积极异例将在诺思中国在长江山谷和干旱导致洪水;当100-hPageopotential高度并且SAH和西南流动的异常变弱的否定异例将在诺思中国在长江山谷和洪水导致干旱时。[出版摘要]