Based on the long-term observed data of meteorological stations in Beijing, the reference crop evapotranspirations (ET_0) for each month and each station were calculated, by using Penman-Monteith method recommended by the FAO.

• 利用北京市各气象站点的长期观测资料 ,使用FAO推荐的Penman -Monteith法 ,计算了各站点逐月参考作物蒸散量ET0 。