云贵高原参考作物蒸散量时空特征及成因分析

为了探究云贵高原地区参考作物蒸散量(ET0)的时空分布特征,基于云贵高原42个代表性气象站点近56 a(1961—2016年)逐日气象数据,利用Mann-Kendall检验探究ET0主要的气象驱动因子,并运用多元回归分析量化了各气象因子对ET0的贡献率.结果表明:云贵高原近56 a风速和气温呈逐年上升趋势,增幅分别为0...

Spatial-temporal distribution characteristics and attribution analysis of reference crop evapotranspiration in Yunnan-Kweichow Plateau

In order to investigate the temporal and spatial distribution characteristics of reference crop evapotranspiration(ET₀)in the Yunnan-Kweichow Plateau, based on the daily meteorological data of 42 representative meteorological stations in the Yunnan-Kweichow Plateau in recent 56 years(1961—2016). Mann-Kendall test was used to explore the main meteorological driving factors of ET₀, and multiple regression analysis was used to quantify the contribution rate of each meteorological factor to ET₀. The results show that: the wind speed and temperature have increased year by year during the past 56 years, with the increase rate of 0.001 2(m·s^-1)/a and 0.018 °C/a, respectively. The solar ra-diation and relative humidity have shown a downward trend, with the decrease rate of 0.007 3(MJ·m^-2·d^-1)/a and 0.074 6%/a, respectively, in the Yunnan-Kweichow Plateau. Over the past 56 years, ET₀ has shown a fluctuating upward trend, with an increase rate of 0.287 1 mm/a. The spatial distribution of ET₀ in the west is higher than the east with significant difference characteristics. The annual average ET₀ of 24 sites ranges from 1 100 mm to 1 200 mm in the western region, and annual average ET₀ of 18 sites ranges from 843 mm to 950 mm in the eastern region. Solar radiation is the main driving factor of ET₀ Plateau in spring, autumn and winter, and temperature is the main driving factor of ET₀ in summer in the Yunnan-Kweichow. The annual contribution rate of various meteorological factors to ET₀ throughout the year is ranked as solar radiation(R_s)> air temperature(T_mean)> relative humidity(RH)> wind speed(u₂). Therefore, solar radiation is the dominant driving factor affec-ting ET₀ changes in the Yunnan-Kweichow Plateau.