摘要
本文利用潘曼(Penman)公式E_(0)=(ΔH+rE_(a))/(Δ+r),计算了宁夏各地自然蒸发量E_(r)值,分析了E_(r)的时空分布特征;以E_(r)/r的比值(干燥指数)作为划分宁夏农业气候区域的指标,并根据E_(r)=L_(t)E_(0)的关系式,订正了宁夏地区春、夏、秋各季的转换系数K值;以计算出的农作物各生育期内自由水面蒸发量E值和实测田间蒸发量′f_(c)的比例系数(′f_(c)/E_(a)),作为土壤-植物-近地表层这个系统的水份状况的重要指标,鉴定出了宁夏灌区小麦、水稻、小糜子等主要作物生育期的蒸发系数j值和耗水量。用水分平衡方程式,求出了作物灌溉量和生育末期土壤水分储水量,为研究宁夏农业气候区划及建立农作物水分平衡预报,提供了依据。
Using Penman’s Formula,we computed the natural evaporation Er of Ningxia districts,and studeid its distribution.The ratio E_(r)/r(aridity index)is used as index for agroclimatological division.The formula E_(r)=K_(t)E_(0)is used to compute E0 for spring,summer and autumn.The proportion coefficient(j_(t)=f_(c)/E_(0))between E_(0)andfield evaporation f_(c)is used as a moisture index for major growth periods of wheat,paddy rice and millet.Based on these information,irrigation requirements are studied.
作者
陈力
Chen Li(Ningxia Meteorological Bureau)
出处
《气象学报》
1982年第2期219-228,共10页
Acta Meteorologica Sinica
