东江流域参考蒸散量及湿润指数变化特征研究

探明东江流域参考蒸散量时空变化特征、分析东江流域湿润指数变化特点,可为东江流域科学制定作物灌溉制度、提高水资源利用效率提供依据。选取东江流域4个代表性站点1952~2013年的气象数据,利用彭曼公式计算参考蒸散量,利用湿润指数公式计算湿润指数,分析了东江流域参考蒸散量和湿润指数时空变化特征。结果表明,东江流域多年平均蒸散量为3.05~3.76mm/d,平均参考蒸散量为3.45mm/d,且呈现出由北向南逐渐增大的特点;东江流域平均湿润指数为1.48,最大变幅为1959年时增长103%,且4个站点湿润指数在1992~2013年整体呈上升趋势,1952~1970年流域总参考蒸散量基本高于60年平均值,1970~1997年流域总参考蒸散量基本低于60年平均值,1997年后有所回升;湿润指数从北向南呈减小趋势,且整体湿润水平较高。

Study on Variation Characteristics of Reference Evapotranspiration and Humidity Index in Dongjiang Basin

To explore the time-space variation characteristics of the reference evapotranspiration in Dongjiang Basin and analysis of the characteristics of the humidity index can provide evidence for making scientific irrigation systems of the crop and raising water resource efficiency. The meteorological data from the year 1952 to 2013 of four representative stations are chosen in Dongjiang Basin. Penman-Monteith formula is used to calculate the reference evapotranspiration and humidity index formula is applied to calculate the humidity index. The time-space variation characteristics of reference evapotranspiration and the moisture index in Dongjiang Basin are analyzed in this paper. The results show that the amount of reference crop evapotranspiration ranges from 3.05 mm/d to 3.76 mm/d and the average amount is 3.45 mm/d; a gradual increasing trend from north to south is obtained; the average humidity index of Dongjiang Basin is 1.48, and the maximum range appeared in 1959 with an increase of 103%; meanwhile, a upward trend from the year 1992 to 2013 appeared in the four sites; the amount of reference crop evapotranspiration in Dongjiang Basin from 1952 to 1970 was basically higher than the average level in the whole 60 years, and the amount from 1952 to 1970 was lower; it rebounded after 1997; A downward trend of humidity index with a relatively high level appeared from north to south in Dongjiang Basin.