【摘要】 基于中国陆地区域1961-2007年逐年/季节平均光合有效辐射(PAR)的空间化数据(10km×10km),结合GIS空间分析技术与Mann-Kendall趋势分析方法对近50年年/季节平均PAR进行时空变化特征分析。结果表明:①全国PAR的空间分布差异明显,总体上呈现东南低、西部高的特点,年均PAR在17.7～39.5molm-2d-1之间。②全国像元平均的年/季节平均PAR表现出一个较明显的波动下降过程,年均PAR降幅为0.138molm-2d-1/10a,不同季节下降幅度存在差异,夏季降幅最大。③逐像元分析显示全国大部分地区PAR呈现显著下降趋势(α=0.05),东部趋势变化较西部明显,夏冬两季在PAR年际变化中的贡献最大。华北地区在不同季节都是下降区域,而青藏高原西北地区在不同季节都表现为上升趋势。④PAR年际变化率空间分布在不同时段差异明显,同一地区PAR年际变化率不仅在不同季节存在差异,而且在不同时段也不相同,总体上1990年代之前PAR下降较快,之后下降趋势变缓。更多还原

【Abstract】 Based on long-term measurement data of weather/ecological stations over China,we calculate and produce mean annual/seasonal Photosynthetically Active Radiation(PAR) spatial data from 1961 to 2007,using climatological calculation and spatialization technique.And we analyze the spatio-temporal variation characteristics of mean annual/seasonal PAR spatial data in China in recent 50 years,by means of Mann-Kendall trend analysis method and GIS spatial analysis technique.The results show:(1) As a whole,the spatial distribution of PAR differs significantly across China,with lower PAR in the eastern and southern parts of China and higher PAR in the western part.Mean annual PAR over China ranges from 17.7 mol m-2 d-1 to 39.5 mol m-2 d-1.(2) Mean annual/seasonal PAR of every pixel over China is averaged and the mean value declines visibly with a fluctuant process,and the changing rate of mean annual PAR is-0.138 mol m-2 d-1/10a.The extents of change in different seasons are different,with the maximum dropping in summer.(3) The analysis by each pixel shows that PAR declines significantly(α = 0.05) in most parts of China.The changing trend in the eastern part is more obvious than that in the western part,and summer and winter play more important roles in the interannual variability of PAR.North China is always a decreasing zone in four seasons,while the northwest of Qinghai-Tibet Plateau turns to be an increasing zone in four seasons.(4) The spatial distributions of the interannual variability of PAR in different periods are not the same.The interannual variability of PAR in a certain region is not only different among four seasons,but also different among different periods.更多还原