宁夏近59年参考作物腾发量时空变化特征分析

Spatiotemporal Variability of Reference Evapotranspiration over the Ningxia Province in the Last 59 Years

依据1951—2009年宁夏回族自治区10个气象站气象资料,运用Penman-Monteith方程计算参考作物腾发量(ET0)月值系列。利用克里金插值、Mann-Kendall突变检验及气候趋势系数等方法分析了宁夏ET0的时空变化特征。结果表明,宁夏地区ET0自北向南逐渐减小,全区多年平均值为982.90mm/a;6月份最大(149.33mm/月),5—7月份占全年的44%;年际变化不剧烈,20世纪50年代相对较大,20世纪60年代开始降低,至20世纪90年代中期以来显著增大;春、夏二季占全年72.62%,冬季最小(8.89%);各地ET0在20世纪60—80年代累积距平呈负值,20世纪90年代至今呈正值。区域腾发量以1958、1995年及2000年为转折点,未来ET0有显著增大趋势,增幅为6.22～50.15mm/(10a),且自北向南逐渐减小。

Based on the monthly meteorological measurements of 10 meteorological stations in Ningxia Province from 1951 to 2009, the monthly reference evapotranspiration（ET0） and yearly ETo are estimated using the Penman-Monteith equation. The characteristics of evapotranspiration on the spatial-temporal variability and trend are analyzed by Kriging method, Mann-Kendall test and climatic trend coefficient method. Results indicate that： In Ningxia, the annual ETo is induces from north to south generally, and the average of multi-years was 982.90 mm/a. There was the maximum value in June, 149.33 ram/month, and the period of ETo mostly from May to July, the ratio is 44%. The variability coefficient was small, so shake of ETo for inter-annual is not very sharply. The values of ETo were bigger in 1950s and induced in 1960s, but increased significantly since 1990s. The ETo have the max value in summer, it was occupied annual about 41.7%, but, the winter is the smallest, 8.89%. The anomaly decades of ETo were negative values from 1960s to 1980s,but have an positive value since 1990s and there were 5 to 9 years appears positive in every decades. The serial of ETo taking 1958, 1995 and 2000 as turning points. In the future, the value of ETo will increase significantly by, 60% stations passed significant test, P=0.01. The increase range is 6.22-50.15 mm/（10a） and induces from north to south generally.