近30年来三江源典型区湿地变化驱动力分析

基于三江源典型区(索加-曲麻河自然保护区)1977—2007年的遥感影像解译数据和统计资料,采用偏相关分析筛选与湿地变化显著相关的因子,通过主成分分析、灰色关联度分析驱动因子对湿地变化的贡献率大小。结果表明:近30年来湿地变化的驱动因素主要为气候因素,其中以年平均气温、年蒸发量和年平均相对湿度为重要影响因子。通过计算主要影响因子对湿地变化的灰色关联度,认为年平均相对湿度和年蒸发量对河流湿地变化的贡献率最大,年平均温度与湖泊湿地、沼泽湿地和河滩地动态变化的关联程度最高。

Driving Forces for Wetland Changes in the Typical Region of the Origin of the Three Major Rivers

In order to identify factors significantly correlated to the wetland changes,a partial correlation analysis on driving forces and wetland changes was performed based on the interpreted data from remote sensing images and the statistic data in the typical region(Suojia-Qumahe Nature Reserve) of the origin of the three major rivers from 1977 to 2007.The significantly related factors were then used to calculate the contribution ratio by principal component analysis and gray correlation degree analysis.The result showed that climatic factors,such as annual average temperature,annual average evaporation and annual average relative humidity,are the main causes for the dynamic wetland changes in recent 30 years.It was suggested that the annual average relative humidity and annual evaporation have the largest contribution to the changes of river wetland,while the annual average temperature has the highest correlation with the dynamic changes of lake wetland,swap wetland and river beach wetland.