通过构建山美水库流域SWAT 模型, 对日场次暴雨过程中流域出口氮素负荷和浓度过程随降雨、径流的变化 特征进行了模拟, 并采用线性相关分析, 对不同降雨条件下的产流与氮素流失的相关性进行研究。结果发现, 山美 水库流域产流过程表现出明显的滞后效应, 径流峰值以滞后于降雨峰值1 d 为主要特征; 氮素流失量变化特征与降 雨、径流变化特征基本一致, 但TN 负荷峰值大多滞后于降雨峰值1~ 2 d, TN 浓度过程基本与降雨过程相反; 不同 等级降雨条件下, 氮素流失量随着雨强的增加而增大, 流域出口径流与T N 负荷呈显著线性相关, 径流是氮素流失 变化的主导因子。

Based on the development o f SWAT model in the Shanmei Reser voir water shed, var iatio n char act eristics of T N load and concentrat ions with the precipit at ion and r uno ff during the pr ocesses o f rainstorm at the o ut let of the w atershed wer e simu2 lated. Furthermore, linear co rr elation analysis w as co nducted to analyze t he r elationship between runo ff and nitro gen lo ss under differ ent pr ecipitatio n intensities. T he results showed that the peak of runoff lagg ed one da y behind the peak o f rainfall. Dur ing the pro cess of rainstorm, nitr og en lo ss var ied consistent ly w ith t he var iatio n process o f precipitat ion and r unoff, and T N load show ed hy steresis propert ies lagg ing behind precipitation peak wit h o ne or two additio nal day s, while TN co ncentrat ion pr ocess show ed the o pposite tr end w ith pr ecipitatio n process. Under differ ent conditio ns of rainfall intensit ies, aver age lo ss rate of nitro2 g en incr eased wit h the increasing o f rainfall intensity, and runoff showed a st atistically sig nificant ( P< 0. 01) positive linear re2 latio nship with TN lo ad. Runoff is the pr imary factor affecting nitro gen lo ss.

福建省科技厅省属公益类科研院所项目( 2014R103424) ; 福建省科技厅重点项目( 2013N0013) ; 福建省教育厅B 类项目( JB12038)