摘要
利用黄河中游三个站点近50a的气象资料，研究了A^°ngstrǒm—Prescott系数不同取值对参考作物蒸散量的影响。结果显示，当A^°ngstrǒm—Prescott系数as和bs分别相差56％和93％时，引起的ET0差异月值在0．6％-26．2％，年值在173．1—197．4mm（18．2％-21．9％）。A^°ngstrǒm-Prescott系数不同取值对ET0的影响程度随地点而变化，即随海拔和日照时数的增加，对ET0的影响程度相应增大。因此在高海拔和高辐射地区，应对A^°ngstrǒm—Prescott系数进行校正。尽管FAO56PM推荐的A^°ngstrǒm-Prescott系数在世界各地广泛应用，但依据本文结果尚不能确定其在中国能否直接使用。随着辐射数据的不断积累，有必要对这些系数进一步研究、验证和校正。
Effect of different A^°ngstrǒm-Prescott coefficients on the reference crop evapotranspiration （ET0 ） was studied,using clata series in last 50 years from 3 meteorological stations in the middle reach of Yellow River. The results showed that 56% and 93% variation of the A^°ngstrǒm- Prescott coefficients（ as ＆ bs ） in this region resulted in 0. 6% - 26. 2% monthly variation, and 18.2 - 21.9% （ 173. 1 - 197.4mm） annual variation for ET0. The effect of A^°ngstrǒm-Prescott coefficients on ET0 was spatial dependent. It increased with the increasing of altitude and sunshine hours. It suggested that A^°ngstrǒm-Prescott coefficients should be calibrated in regions with high altitude and intensive radiation. Though the A^°ngstrǒm-Prescott coefficients were recommended by the FAO 56 PM to apply to the world wide, they could not been applied to in China directly according to this result. It seemed necessary to be validated and calibrated further to these coefficients.
出处
《中国农业气象》
CSCD
2007年第1期29-35,共7页
Chinese Journal of Agrometeorology
基金
社会公益项目(2004DIB3J095)
