宁夏参考作物蒸散量的时空变化特征分析

Temporal-spatial Characteristics of Reference Crop Evapotranspiration in Ningxia

为了确定合理的灌溉制度,保护生态环境,应用Penman-Monteith公式以宁夏2000-2012年的气象观测资料计算了参考作物蒸散量。在此基础上采用克里格(Kriging)插值方法,生成宁夏参考作物蒸散量分布图。结果表明,宁夏地区平均参考作物蒸散量的多年平均值为964.92mm,ET0随时间呈显著下降趋势,下降幅度约为1.14mm·a^(-1)。年参考作物蒸散量的空间分布总趋势自北向南逐渐减小,北部引黄灌区最大1 136.40mm·a^(-1),南部山区最小706.0mm·a^(-1)。年内季节变化为夏季>春季>秋季>冬季;逐月变化呈单峰变化趋势,峰值出现在6月,5-7月参考作物蒸散量均较大,占年值的43%,这与当地气候相吻合。

In order to establish a reasonable crop irrigation system and to preserve eco-environment, reference crop evapotranspiration （ET0） in Ningxia was calculated by Penman-Monteith equation based on the meteorological data during 2000 to 2012. The distribution pattern of ET0. was charted by using the Kriging interpolation method. The multi-year average ETo was 964.93 mm,it decreased significantly with an average of 1.14 mm·a^-1. For the special distribution,the annual ETo decreased from north to south generally： higher in north plain （1 136.40 mm·a^-1） ,and lower in south mountainous region （706.02 mm·a^-1）. Seasonal ETo was in the order of summer〉spring〉autumn〉winter. Within a year,it was high from May to August and low from November to next February, while the highest value appeared in June, accounted for 43 % of the total year,which was in accordance with the local climate.