甘肃玛曲县近40a潜在蒸散量的变化趋势

Trends of Potential Evapotranspiration in Maqu County of Gansu Province in Recent 40 Years

利用玛曲县气象观测站1971～2010年的地面气象观测资料,运用Penman-Monteith公式计算得出玛曲县逐月潜在蒸散量值。通过Mann-Kendall法、小波分析等统计方法进行分析,结果发现玛曲县潜在蒸散量年际变化呈逐年上升趋势,上升趋势为12.0 mm/10 a;并且存在准10 a和准5 a周期。潜在蒸散量与小型蒸发皿蒸发量的逐年变化趋势基本一致。月平均潜在蒸散量呈单峰型,从1月到7月呈上升趋势,7月是蒸散量最大月,从8月又开始下降。并且月平均潜在蒸散量最大值出现在年平均气温最高和降水量最多的7月。玛曲县潜在蒸散量的季节分布与该地降水量的季节分布和气温的高低季节变化一致。

Based on meteorological data during 1971-2010 from Maqu weather station,the monthly potential evapotranspiration was calculated by using the Penman-Monteith method,and the trends of potential evapotranspiration in Maqu were analyzed by using statistic analysis,Mann-Kendall method and wavelet analysis.The results indicated that the annual variation of potential evapotranspiration presented a significant increasing trend with the rate of 12.0 mm/10 a,and there was quasi-10 and quasi-5 years change period.The trend of pan-evaporation was similar to the potential evapotranspiration in Maqu.Monthly mean of the potential evapotranspiration presented single peak with increase from January to July and going down from August.The maximum of monthly mean potential evapotranspiration occurred in July.The seasonal distribution of potential evapotranspiration was consistent with precipitation and temperature in Maqu.