The Lake Status Change of China since LGM and Its Significance for Palaeoclimate

中国古湖泊数据库收录的42个湖泊,提供的湖泊水量每千年变化的空间信息,可以用来系统分析中国区域末次冰盛期以来大气环流变化的状况.研究结果表明:我国西部从末次冰盛期以来直至全新世中期均为较湿润的气候状况,推测冰期内的湿润条件主要与西风带的降水以及低温低蒸发密切相关,而全新世主要为夏季风降水增加所致;全新世晚期气候趋干明显.我国东部的大部分区域在冰盛期和晚冰期较为干旱;只是在全新世有效降水状况才有大幅度的改善,全新世中期夏季风降水的效应仍然相当显著,控制的范围可达整个中国西部,同时位于现代季风气候区的中国东部,有效降水的峰值区的变化似乎存在从北往南的穿时性,南方有效降水峰值出现在晚全新世.而西南季风区湿润状况的明显改善发生在晚冰期,比东南季风区发生的早,显然这与两个季风系统的相互消长有一定的关系.我国东北区的湿润状况改善的也较早,显示了独特的季风气候机制.;The 42 lakes compiled in the Chinese Lake Status Data Base (CLSDB), has provided the information of the spatial changes of lake status for each one-thousand year, which can be purposed for research on the atmospheric circulation changes of Chinese region since LGM, The results have shown that, the relatively wet conditions of western China from LGM to Mid-Holocene was probably related to the precipitation brought by the westlies and the low evaporation in Glacial period, and summer monsoon precipitation in Holocene.And the climate turned drier since late-Holocene.Most area in eastern China during LGM and late-Glacial was relatively dry, and turned wetter in Holocene.The summer monsoon precipitation during Mid-Holocene might reach the whole western China.In eastern China, there exists the diachronity for the maximum effective precipitation from north to south during Holocene,occurring during late-Holocene in southern china.The wet condition of southwestern China occurred clearly in late-Glacial, which is earlier than in southeastern China, suggesting that a balance occurred between these two monsoon systems.The earlier oc-currenceof wet conditions in northeastern China suggests an independent monsoon systems in this area.