Abstract:
MiddleYangtzeinSouthChinaiswellknownbythefrequentoccurrenceoffloodinginassociationwithdrought
events.However,lessisknownaboutthehydrologicalvariationintheancienttimes.Hereweareabletoreconstructthepaleohydrologicalconditionssince13kaBPinthisregionbasedonthesynthesisof4proxiesextractedfromtheDa
jiuhupeatlandand
stalagmiteinHeshangcavenearQingjiangRiver.Threelong-termdrierperiods(11.7-10.7kaBP,6.4-5.5kaBPand4.0-
3.0kaBP)andthreelong-termhumid/floodingperiods(13.0-11.7kaBP,8.7-6.4kaBP,3.0-1.7kaBP),eachlastingover
onethousandyears,wereidentifiedinthistimeinterval.Thehumidperiodat8.7-6.4kaBP(knownasHoloceneOptimum)
isofabroadregionoronaglobalscale,whenthesedentaryvillage-basedricecultivationwasdeveloped.Thesubsequentdrier
periodsat6.4-5.5kaBPisalsoofabroadregionorevenofglobalscalewhenthecomplicatestate-levelsocietystructurewas
established.Thelong-lastingdrierperiodscouldbepresentedpriortoorpostthelong-lastinghumidperiods.Inaddition,5
short-termdroughtevents(9.8-9.2kaBP,9.0-8.7kaBP,5.0-4.2kaBP,1.7-1.1kaBP,0.7-0.0kaBP)and5shorttermhumidperiods(
10.7-9.8kaBP,9.2-9.0kaBP,5.5-5.0kaBP,4.2-4.0kaBP,1.1-0.7kaBP)werealsoidentified.
InmiddleYangtzeregion,mostdrierperiodsoccurredatthewarmconditions,differentfromthecold-droughtassociationin
NorthChina.Meanwhile,thehumidclimatecouldoccuratboththecoldandwarmconditions,indicatingthecomplicaterelationshipbetweentemperatureandhumidity.Itisnotablethatthearidityincreaseswhenthetemperatureshiftsfromonestateto
another(i.e.,fromcoldtowarmorfromwarmtocoldconditions)inMiddleYangtze.Hydrologicalconditionsalsoplayanimportantimpactonhistoricalculturesinthisregion