中国近地层风能资源的时空变化特征

近地层风能蕴量是随着大气背景的变化而变化的特殊物理量,研究在全球变暖的背景下近地层风能资源的气候变化与分布特征,对我国风能产业的发展规划具有重要的理论意义和实际价值.选取全国186个地面站在1960-1999年共40年的常规风速观测资料,采用了分段线性拟合、变化速率计算等方法,对研究区域内年平均风速进行了趋势分析,又通过对逐年的平均风能密度做REOF分解,提取了具有不同风能变化型态的7个显著区域,探讨了风能资源的时空气候变化特征.研究结果发现:中国逐年平均风速呈现"冬春大、夏秋小"型,40年来各季和全年的年平均风速、风能密度均是显著减弱的,在70年代中前期之后出现显著的持续下降趋势;北方区、东北区、东部沿海区的风能资源相对最为丰富,变化幅度也最大,中部区风能资源最为贫乏,变化幅度最小.风能资源的分布特点和变化趋势与影响我国的冬、夏季风系统的气候变化关系密切.

Temporal and Spatial Variety Characteristics in Near-surface Wind Energy in China

There exists considerable interest in the potential impact of climate change on the feasibility of renewable energy sources including wind energy.This paper examines the temporal and spatial characteristics of the near-surface wind power,which are useful and meaningful to wind energy industry.The wind routine observations from 186 meteorological stations are selected over the whole continent of China during the latter half of the 20th century.Multi-period linear fit and varied rate are used to investigate the variety trends of annual and seasonal average wind speed or wind energy density on 10 m.The temporal and spatial characteristics are analyzed from the seven different sections on the annual average wind energy density,which come from REOF analysis.The results indicate that annual mean wind speeds are higher in winter and spring,weaker in summer and autumn.The trends in annual average wind speeds and energy density are significantly decrease over the period 1960-99,with the majority of decrease after 1972;In the northern zone,the northeastern zone,and the eastern zone,wind energy density is the greatest,again with the largest magnitude changes;on the other hand,wind energy density in the inside zone is the poorest with the smallest magnitude change;These changes in wind power sources are strongly linked to changes in the synoptic-scale circulation.The majority of the decrease is attributable to the decrease in winter monsoon,Mongolian cyclone,Dongbei cyclone,and the Pacific tropical cyclones.