中文摘要：

为了了解农田排水及养分流失特性,利用DRAINMOD-N模型对湖北漳河灌区水旱农田地下水位变化及地表径流氮素流失过程进行了模拟.结果表明：水田和旱地地下水位逐日实测值与模拟值的相关系数分别为0.817和0.849,效率系数分别为0.209和0.582,相关性较好.另外,农田排水氮素流失模拟值与实测值非常接近.水稻田地表排水铵态氮流失量要高于硝态氮,旱作硝态氮流失量远远高于铵态氮.水田和旱地硝态氮模拟的相对误差分别为8.35%和5.45%,铵态氮的相对误差分别为10.99%和14.11%,都在允许误差范围内.

英文摘要：

In order to understand the characteristics of farmland drainage and nitrogen loss,the processes of groundwater table changes and nitrogen loss in surface runoff from upland and paddy fields in Zhanghe Irrigation District,Hubei Province,are simulated based on DRAINMOD-N model.Results show that for the paddy field,the correlation coefficient between the observed and simulated daily groundwater tables is 0.817,and the model efficiency is 0.209;and for corn field,they are 0.849 and 0.582 respectively,with good correlation.Besides,the simulated daily accumulated nitrogen loss from farmlands is quite close to the observed value.The ammonium-nitrogen loss from the paddy field is higher than that of nitrate-nitrogen;but the nitrate-nitrogen loss from the corn field is much higher than that of ammonium-nitrogen.For the paddy field,the relative error of nitrate-nitrogen loss simulation is 8.35%,and that of ammonium-nitrogen loss is 10.99%;while for the corn field,they are 5.45% and 14.11% respectively,which are within the range permitted.