中文摘要：

为分析农田水分运移规律,以华北平原位山引黄灌区典型田间为研究对象,应用Hydrus-1D模型连续模拟了2006-2009年的田间水分运移过程。对模型中表面阻抗的计算方法进行了改进,从而改善了蒸散发的模拟结果,与涡度相关系统的实测蒸散发数据对比表明了改进的合理性。对蒸散发的分析表明,对于种植季节性作物的农田,叶面积指数（leafarea index,LAI）是影响蒸散发季节变化过程的重要因素,而气象条件主要决定其在较短时间尺度（如一周）内的波动。与时域反射仪（time domain reflectometry,TDR）实测土壤含水率的对比表明,模型对土壤含水率的模拟精度较高。水量平衡分析结果表明,降雨和灌溉的80%由蒸散发消耗,在汛期农田通过排水发生田间渗漏损失。

英文摘要：

Water cycle during 2006-2009 in a typical agricultural field of the Weishan irrigation district,which is located along the downstream of Yellow River in the North China Plain,was analyzed using the Hydrus-1D model.The equation for calculating the bulk surface resistance was modified according to the observed data.The simulated ET was compared with the observed ET by the eddy covariance system,and the result showed that simulation using modified resistance equation provided much better results than that of the original model.ET analysis showed that,for areas covered with seasonal vegetation,LAI determined the seasonal variation of ET,while weather condition determined ET variation at a much smaller time scale（e.g.,one week）.Comparing the simulated soil water content with the observed data by TDR,showed that the model could simulate soil water appropriately.Water balance analysis showed that about 80% of the rainfall and irrigation were consumed by ET,and drainage from the field mainly occurred during rainy season.