全新世以来南疆地区气候环境演变与人类活动的关系

The Paleoclimatic Evolution and its Relation to Man’s Activities in Southern Xinjiang, Since about 12.0 ka BP

根据南疆地区不同沉积相的沉积记录的研究 ,初步建立了南疆地区 1 2 ka BP以来气候环境演化序列。研究揭示 ,此期间南疆地区气候与环境的演变具有较为显著的西风型特征 ,共经历了 5次相对暖干和 4次相对冷湿时期。特别是在全新世大暖期中出现于 7.0～ 5.0 ka BP期间相对暖湿的气候环境特征可能与西南季风势力的增强有关 ,而且还揭示了此地区暖干化趋势存在阶梯式增强的特征 ,研究还发现 ,近 4ka BP以来 ,气候环境的变化与一些人文事件如古城的废弃、丝绸之路的兴衰和人地关系类型的演化存在着一定的关系。

Based on a synthetic study on variety of geologic records in southern Xinjiang, Characteristics of palaeoclimatic evolution in southern Xinjiang are basically identical to those revealed by other geological records in Xinjiang. Palaeoclimatic changes presented apparent Westlies Style model: during cold periods, relative humidity increased and lake water level rose; but in warm periods, the dry regime aggravated. The history of paleoclimatic changes is reconstructed preliminary in this paper and indicates that it has been experienced 5 relative warm(or hot) dry periods and 4 relative cold (or cool) humid periods. The warming peaks occurred at about 11 500~11 000 a、9 400 a、7 500~7 000 a、6 500~6 000 a、3 000 a、2 000 a and after 1 000 a BP, the cold peaks at 11 000~10 000 a、8 800 a、5 000~4 500 a、3 300 a and 1 500 a BP. The only relatively warm humid phase during 7 000~5 000 a BP may be deduced from the Megathermal Maximum, resulting from the strengthened summer southeastern monsoon force. The most interesting comparison shows that the above mentioned warm dry periods since about 4 0 ka BP basically coincide well with the periods of the phases of ancient cities abandoned in southern Xinjiang and also with the rise and decline of the ancient Silk Road. The quasi correlation between the changes of climate and the type and content of man land relationship implys that the natural evolution of climate and environment perhaps played a very important role in affecting man land relationship in arid area.