拉萨河流域潜在蒸散发的气象因子敏感性

Sensitivity analysis of potential evapotranspiration to key climatic factors in the Lhasa River Basin

蒸散发可以反映气候变化对水资源的影响状况,根据拉萨河流域两个站点1955-2018年的逐日气象数据,采用FAO-56-Penman-Monteith公式计算潜在蒸散发(ET0),进而采用敏感性分析、Mann-Kendall趋势检验、气候倾向率及小波分析等方法对拉萨河流域ET0的变化特征及其影响因素进行分析。对比两个站点的变化规律,结果表明:流域ET0整体对最高温度最为敏感,最高温度的贡献率最大,气象因子的敏感系数年内变幅为相对湿度>最高温度>风速>日照时数>最低温度;流域ET0的日变化趋势为每10年增加0.03 mm,Mann-Kendall检验流域ET0增长并不显著;流域的ET0在25~30a尺度上周期振荡明显,出现了7次循环交替。

Evapotranspiration can reflect the impact of climate change on water resources.Based on the daily weather data from1955 to 2018 at two sites in the Lhasa River Basin,the potential evapotranspiration(ET0)was calculated using the FAO-56-Penman-Monteith formula.The sensitivity analysis,Mann-Kendall trend test,climatic tendency rate,and wavelet analysis were used to analyze the variation law of ET0 in the Lhasa River Basin and its influencing factors.Comparing the changes changing characteristics of of the two stations,the results show that:The whole basin ET0 is the most sensitive to the highest temperature,and the contribution of highest temperature contribution to ET0 was the largest.The sensitivity coefficient of meteorological factors varies vary within the year:relative humidity>maximum temperature>wind speed>sunshine hours>minimum temperature,respectively;The daily variation trend of ET0 in the basin is was 0.03 mm per 10 years and the increase of ET0 in the watershed by Mann-Kendall was not significant;The ET0 of the basin has a cyclical oscillation on the 25-30 year scale,and there are were obviously 7 cycles of alternating.