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为了深入分析中国参考作物蒸散量(ET_0)的时空分异特征,利用中国843个气象测站1951-2014年的观测资料,采用FAO—Penman-Monteith(98)公式计算ET_0.依靠处理定性概念与定量描述不确定转换的云模型,研究了ET_0时空分布的均匀性和稳定性,并对ET_0在月、季、年及空间上的变化特性进行了分析.结果表明ET_0年际变化呈现逐年波动式的下降趋势,整个区域的ET_0以-1.72 mm/10 a的倾向率逐年下降;ET_0年际变化表现为单峰型,11月到次年3月分布较均匀、稳定,4—8月较为离散、不稳定;ET_0四季分布差异明显,夏季最大,春季次之,秋、冬季最小;秋、冬季ET_0分布较春、夏季更均匀、稳定;时间尺度越大,均匀性和稳定性越低.中国ET_0在空间上总体呈现由东北地区向西北地区递增的趋势,西南南部和华南地区相对较高.与时间分布相比,空间分布上较不均匀、不稳定,说明时间变化较为连续,空间变化较为离散.
In order to further analyze the spatio-temporal variability of China’s reference crop evapotranspiration (ET_0), ET_0 is calculated using the observational data of 843 meteorological stations in China from 1951 to 2014 and the formula of FAO-Penman-Monteith (98) Quantitatively describe the cloud model with uncertain transformation, the distribution and the stability of ET_0 space-time distribution are studied, and the monthly, seasonal, annual and spatial characteristics of ET_0 are also analyzed. The trend of ET_0 in the whole area decreased year by year at the rate of -1.72 mm / 10 a; the change of ET_0 in the year was single-peaked, the distribution was more uniform and stable from November to next March, and was more discrete in April-August , But the ET_0 distribution was significantly different in the four seasons, with the highest in summer, the lowest in spring and the lowest in autumn and winter; the distribution of ET_0 in autumn and winter was more uniform and stable than that in spring and summer; the higher the time scale was, the lower the uniformity and stability were. ET_0 showed an overall trend of increasing from the northeast to the northwest in the space, while the southwestern part of Southwest and the south of China were relatively high.Compared with the time distribution, the spatial distribution of ET_0 was less uniform and unstable, indicating that the time variation was more continuous and that space Of more discrete.