陕西卤泊滩改良盐渍农田实际蒸散发估算方法比较

Comparison on estimation of actual evapotranspiration from improved salinized land of Lubotan,Shaanxi

蒸散发是能量循环与水循环的结合,准确测定与估算区域蒸散发对水资源规划与管理、农业节水研究、作物产量模拟等方面具有重要的现实意义。以陕西省富平县改良盐渍农田为研究对象,以涡度相关法的实测资料为基准,采用Hargreaves-Samani法(HS法)、修正的彭曼-蒙蒂斯法(P-M法)、Priestley-Taylor法(P-T法)估算盐渍农田实际蒸散量,比较并检验了在不同时间尺度,不同生育期,不同天气条件下这些估算方法的精度,以期为类似盐渍农田蒸散量估算提供借鉴。计算结果表明:在研究期内,P-M法估算效果最优,P-T法次之,HS法效果较差,且精度允许范围内,从计算方法的繁简与需求资料难易角度考虑,P-T法较P-M法更适合。

Evapotranspiration is a combination of energy circulation and terrestrial water circulation. It has significant meaning to accurately monitor and estimate evapotranspiration for water resources planning, ag- riculture water saving research, crop yield simulation. This paper takes improved salinized land in Fuping county of Shannxi province as the research object, based on the measured data of eddy covariance meth- od, Hargreaves - Samani method （ HS method）, modified Pangman - Montis method （PM method）, and Priestley -Taylor method were used to estimate the actual evapotranspiration （ETa） of salted farmland, and the accuracy of these estimation methods under different time scales, different growth stages and dif- ferent weather conditions were compared and tested to provide reference for estimating the evapotranspira- tion of salted farmland. The results showed that P - M method is the best, then followed by P - Tmethod, while HS method is the worst in the research period. The P -T method is more suitable than the P -M method considering the calculation method and the difficulty of the demand data.