山西省参考作物蒸散量的时空变化特征

基于山西省境内70个地面气象观测站1960—2019年的逐日降水量、气温、日照时数、相对湿度、风速、水汽压等气象资料,应用Penman-Monteith公式计算参考作物蒸散量(ET₀),对山西省ET₀的时空变化特征及不同气候带和海拔的蒸散特征进行定量分析。结果表明: 1960—2019年,研究区年均ET₀在空间上呈现由西向东逐渐递减的趋势;以1982年为拐点,前后两个时段均呈逐年增加趋势,月际、旬际波动为单峰变化曲线。不同气候带ET₀的差异性表现为:温带半干旱气候区的年、春、夏、秋季ET₀高于暖温带半湿润气候区和暖温带半干旱气候区;冬季,暖温带半湿润气候区ET₀最高。不同海拔ET₀的差异性表现为:＜660 m海拔区的年、夏、秋、冬季ET₀高于其他海拔区域。

Spatiotemporal variation of reference evapotranspiration in Shanxi Province,China

Based on data of daily precipitation, temperature, sunshine hours, relative humidity, wind speed and vapor pressure of 70 meteorological stations from 1960 to 2019 in Shanxi Province, the Penman-Monteith model was applied to calculate the reference evapotranspiration (ET₀). The spatiotemporal variations of ET₀ as well as the ET₀ in different climatic zones and at different altitudes were quantitatively analyzed. The results showed that the mean annual ET₀ decreased from west to east in 1960-2019. A jumping point was detected in 1982, with the mean annual ET₀ increased both in 1960-1982 and 1983-2019. The monthly and ten-day changes of ET₀ showed single peak curves. The variation of ET₀ in different climatic zones was as follows: ET₀ in temperate and semi-arid areas was higher than that in warm temperate and semi-humid areas and warm temperate and semi-arid areas in spring, summer, autumn and the whole year, while in winter, the highest ET₀ was in warm temperate and semi-humid areas. ET₀ varied with altitudes, with ET₀ in <660 m altitude areas being higher than that in other altitudes in summer, autumn, winter and the whole year.