21世纪以来黄河源区高原湖泊群对气候变化的响应

利用2001~2006年逐年汛前期和汛后期两个时相黄河源区湖泊群EOS-MODIS卫星遥感资料和气候、冻土监测数据,分析了21世纪以来黄河源区高寒湖泊群的最新动态变化,描述了器测时期以来该区域气候的演变背景,揭示了湖泊面积和数量对气候、冻土环境变化的响应。结果表明:近52年来源区出现了气温显著升高、降水量增加和蒸发量增大的气候变化大背景,但2001年以来气候以暖湿为主要特征的同时,蒸发量明显减少,且受气候变暖的影响冻土环境表现出冻土厚度减小、冻结时间缩短等退化趋势;2001~2006年黄河源区湖泊群的最新波动表现为湖泊面积增大、数量增多的一致性变化迹象,这种波动趋势在汛前期表现得较汛后期更为显著,并以湖泊数量的变动最为明显;21世纪以来黄河源区湖泊扩张、数量增大正是同期降水量增大、蒸发量减少和冻土退化加大了地下冰融化水补给量等气候变化的直接结果。

Response of the Plateau Lakes to Changes of Climate and Frozen Earth Environment in the Headwaters of the Yellow River since the 21st Century

Using the data of remote sensing of lakes from EOS-MODIS satellite and climate,frozen earth by monitoring from 2001 to 2006 in the headwaters of the Yellow River, this study analyzed the dynamic change of the high and chill lakes in the concerned region since the 21st century, described the developing background of the climate and frozen earth since the observation with apparatus, and then revealed the response to changes of the climate and frozen earth environment in terms of the area and the number of the lakes. The results indicated: the latest fluctuation coming from the headwaters of the Yellow River was an unanimous indication of the increase in area and quantity, which was more remarkable in the earlier flood period than in the later, and the change of the lakes in quantity was most obvious; the large background appeared in the last 52 years, including the increase in temperature, precipitation and evaporation, but the chief climatic characteristic was warm and moist since 2001,at the same time, the evaporation had been lessened apparently, and the thickness of the frozen earth had been decreased and the frozen time shortened due to the warmer climate; the lakes expanded and the number increased, at this time, the precipitation increased, evaporation decreased and the frozen earth deteriorated, which reinforced the melting of groundwater, all of these were the direct result of the changes of climate and frozen earth environment.