Paleohydrologic Reconstruction Of Special Holocene Stages In Lake Huang Qihai In Inner Mongolia, China

Huangqihai was a closed basin lake, located at the edge of the monsoon regionwhich is so highly sensitive to the evolution of the East Asian monsoon climate thatbecome the focus of attention of Quaternary climate change research. Many scholarsmade a lot of qualitative researches by using climate proxies. Based on modernhydrological characteristics and a large number of results of previous studies onnorthern China since the Late Quaternary sedimentary environments andpaleoclimate evolution, through studying the lake sedimentology, geomorphologylakes and lake chronology to establish the lake basin-wide water balance equation,by successive approximation to find modern climate area which is similar to theancient basin area, to determine the relevant parameters and quantitative researchmethods to restore ancient precipitation, this article tries to reconstruct the ancientbasin hydrological information of Huangqihai at three typical stages of the Holoceneof.10.0~8.0kaBP,8.0~6.0kaBP and3.0~2.0kaBP. Primary conclusions are asfollows:Huangqihai basin located at the north of the edge of the East Asian monsoonregion, by using Holocene geomorphic evolution of ancient lakes ruins datingsedimentary records and dating data, we recovery all the typical period of ancientlake levels and lake area. The results show that: basin of Huangqihai at three typicalstages of the Holocene of.10.0~8.0kaBP,8.0~6.0kaBP and3.0~2.0kaBPcorresponding to the elevation of1298~1304m respectively,1298~1325m and1288~1292m. They are height higher than the current lake height (1264m) of34~40m respectively,57~61m and24~28m, and reconstruction of the ancient lakeheight385~396km2respectively,530~546km2and301~313km2.By using successive approximation to find similar area of modern climate ofancient basin area, we reconstruct the precipitation for ancient typical time period.The results show that: the study area corresponds to the Holocene14~3kaBP thelast high solar radiation phases: early Holocene10.0~8.0kaBP and middleHolocene8.0~6.0kaBP are high lake stages, the precipitation reconstructions ofancient basin Huangqihai are498~508mm and573~585mm, respectively higherthan the modern average annual rainfall122~132mm and197~209mm and highup to40m and61m above the current lake. Especially in the mid-Holocene, theclimate is accepted as the warmest and humid period, and the climate of Huangqihai basin is also at the optimum period since Holocene. The lake level of Huangqihaifluctuations decreased in the Late Holocene during3.0~2.0kaBP time, thereconstructed precipitation of Huangqihai basin is469~477mm, above the currentheight26m, at that time, the ancient basin hydrological characteristics have beengradually close to the level now.Huangqihai basin experienced three stages of typical ancient environment ofholocene changes as follows: after the end of the last glaciation, paying sea basininto the early holocene, the temperature rise, but also relatively cold, rapidlyincreasing rainfall than in other areas, for cold wet phase. Huangqihai basin inmiddle-holocene temperature rising fast, into the warm period, the stableprecipitation increase, at this time for paying the sea basin into the warm wet phase,as the climate optimum period; In the end of the holocene, for paying the sea basinexperienced significant climate change, by warm wet into a person.