水分胁迫条件下羊草群落生育期双作物系数计算方法的验证

基于浑善达克沙地2005-2006两个不同水文年对羊草、拂子茅、冰草构成的羊草群落生育期生境中气象因子及生理因子野外观测试验数据，用联合国粮农组织FAO-56分册中介绍的方法计算了羊草群落生育期基本作物系数和土壤蒸发系数，并对基本作物系数进行了地区气象因素和牧草单叶气孔阻力校正。用校正后的作物系数模拟计算的蒸腾、蒸发量与实际观测值间进行了拟合相关图、拟合优度参数法的有效性检验。结果表明：计算的蒸发、蒸腾量与实测结果基本接近。考虑水分胁迫时，有条件的地区应该对作物系数进行地区气象因素和单叶气孔阻力校正。

The variation of evapotranspiration in growing season for the Leymus chinensis community in the south east part of the Otindag sandy area

This paper based on the field experimental data in climate and physiology factors from 2005 t0 2006 to simulate the daily the evapotranspiration of the Community of Leymus Chinensis in the Otindag sandy area in two different hydrology yeas using dual crop coefficient approach presented in the FAO irrigation and drainage paper 56 (FAO56,1998,Crop evapotranspiration ,Guidelines for computing crop water requirement) 。The simulation results were assessed by the approach of consisting in presenting a graphical representation of model simulated transpiration and evaporation compared with observed values and by the regression between observed and model simulated values forced to the origin. The evapotranpiration values assessed were analyzed according to the physiology characteristics, change in canopy structures, climate factors and root zoon water content .The evapotranpiration and average daily evapotranpiration strength of growing stages were determined and the variations of them were revealed.