中文摘要：

基于水文、气象、土地利用及农业耕作等基础资料,构建了贾鲁河流域SWAT模型,率定和验证结果表明,径流及氨氮模拟较好,月均评价系数（Ens）均大于0.78.利用上述模型,对贾鲁河流域旱作农业区非点源污染负荷产生规律及其影响因素进行分析,结果表明,在平水年小麦-玉米轮作条件下,贾鲁河流域硝酸盐氮总产生量为15546.3t·a-1,有机氮总产生量为1216.58t·a-1,耕地单位面积氮负荷产生总量90.51kg·ha-1,大于以水田为主的耕地污染负荷;氨氮入河负荷为1128.64t·a-1,7—8月份有机氮及氨氮入河负荷分别占全年负荷的94.79%和78.42%,其月产生量与月均降雨量相关系数分别为0.804和0.8531;虽然玉米期和小麦期氮肥的施用量相当,但是玉米期氮流失量要远远大于小麦期.

英文摘要：

Based on the basic data of hydrology,meteorology,land use and agricultural cultivation,a SWAT model of semi-humid dry farming areas was built.The results indicated that monthly simulations for flow and ammonia are fairly good.The monthly evaluation factor Ensis higher than 0.78.Using the SWAT model to analysis the factors of non-point source pollution load distribution and influencing factors in Jialu river basin,the results showed that the total amount of nitrate nitrogen and organic nitrogen are 15546.3t·a-1 and 1216.58t·a-1 respectively in wheat maizerotation system of normal flow year,and that the nitrogen production in dry land is higher than the paddy field area,reaching 90.51kg·ha-1.The amount of nonpoint source pollution load of ammonia is 1128.64 ton,and the organic nitrogen and ammonia nitrogen in the river are accounted for 94.79%and 78.42% of the annual load in July and Au-gust,the correlation coefficients of which with monthly average rainfall are 0.804 and 0.8531 respectively.Although the application rate of nitrogen fertilizer in maize period and in wheat period are almost the same,the amount of nitrogen loss in maize period is much greater than that of in wheat period.