中文摘要：

基于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分册中最新双作物系数法计算分析了羊草群落生育期不同降雨条件的需水量。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。用羊草生育期生理特性、冠层结构变化、气象要素和根系层土壤含水率变化对计算结果进行了分析,得出生育期各生长阶段蒸散量和日平均蒸散强度及其它们的变化规律。

英文摘要：

Based on the field experimental data of climate and physiology factors from 2005 to 2006,using the dual crop coefficient approach presented in the FAO irrigation and drainage paper56（FAO56,1998,Crop evapotranspiration,Guidelines for computing crop water requirement）we imulated the daily the evapotranspiration of the community of Leymus Chinensis in the Otindag sandy area in two different hydrology yeas.The simulated transpiration and evaporation were assessed by the regression between observed and simulated values.The evapotranpiration values were analyzed according to the physiology chacterastics,canopy structure,change climate factors and root zoon water content.The evapotranpiration and average daily evapotranpiration strength in growing stages were determined and the variations of them were revealed.