10ka BP来石羊河流域气候演变特征分析

Climate Evolution in the Shiyang River Basin of China since 10 ka BP

根据石羊河流域及周边地区的大量研究结果分析,整理和建立了10 ka BP来石羊河流域气候演变序列,可以划分出主要的7个气候湿润期和6个干旱期.近50 a以来石羊河流域气候干旱化趋于显著,有4个主要特点:1971—2000年比1951—1980年平原绿洲地区年平均降水(气温)增加(正常);高山和沙漠边缘地区降水量减少(气温正常或偏高);大部分地方年平均蒸发量普遍减少10～131 mm;年平均沙尘暴、雷暴日数减少.

Based on the study results of water resources, climate and glacier variations in the Shiyang River Basin and its adjacent regions, the features of dryness/wetness evolution since 10 ka BP are investigated and its variation series is built. There are seven wet and six dry climatic phases recognized. Furthermore, there are four features in the main climate change in the last 50 a. It is found that the mean annual precipitation in the oasis in the region from 1971 to 2000 was higher than that from 1951 to 1980, but the temperature change in the oasis was not evidence. Meanwhile, the precipitation in the edge of the high mountains and the desert decreased evidently, with an increasing temperature. Furthermore, the mean annual evaporation in most of the region had decreased 10～131 mm, the days of the mean annual sand storm and the thunderstorm had decreased too.