新疆旱区草地参考作物腾发量随机模拟及其应用

Application of stochastic model to simulation of reference crop evapotranspiration in grassland of arid region

本文根据新疆地区乌鲁木齐、吐鲁番、伊宁3个气象站40年逐日观测资料,应用FAO 1998 Penman-Monteith公式,计算乌鲁木齐站（1959-2000年）、吐鲁番站（1961-2000年）和伊宁站（1961-2000年）的历年逐日ET0。在此基础上,对各站多年平均ET0序列进行了随机模拟。结果表明：3个站ET0年内变化趋势大体一致,都具有很强的季节性,总体上吐鲁番站的ET0最高,伊宁站最低;年际变化呈现递减的趋势。通过预测值和Penman-Monteith法计算值对比,说明随机模型的预测结果良好,相对误差范围在实用范围之内,可为计算灌区作物需水量和优化灌溉制度提供一定的依据。

The Penman-Monteith formula was used to calculate the daily reference crop evaportranspiration ET0 according to the daily meteorological data observed at Urumqi Station, Tulufan Station and Yining Station, located at Xinjiang Autonomous Region, in the period from 1961 to 2000. The mean annual series of ET0 for these stations were simulated by stochastic method. The results indicate that the variation trends of ET0 in these station in a year are almost the same and have obvious seasonal characteristics. The magnitude of ET0 at Tulufan is the highest and that at Yiling is the lowest. Generally, the ET0 at these stations tends to decrease year by year. It is found that the predicted ET0 by using the stochastic model is approximately agree with that calculated from Penman-Monteith formula, the relative error of the predicted ET0 is in the practical range. It demonstrates that the stochastic simulation model can be used to calculate the water requirement in irrigation district and provides the data for optimization of irrigation practice.