黄土丘陵区岔口小流域暴雨条件下氮素随地表径流迁移特征  

Effects of Rainstorm on Export of Nitrogen with Surface Runoff in Loess Hilly Region of Chakou Watershed

作　　者：闫瑞[1] 闫胜军[1] 赵富才[1] 郭青霞[1] 

机构地区：[1]山西农业大学资源环境学院,山西太谷030801

出　　处：《水土保持学报》2014年第5期82-86,共5页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41071345)

摘　　要：通过对岔口小流域流量和水质的同步监测,在流域尺度上研究暴雨条件下氮素随地表径流迁移特征。通过SMC取值分析流域4个季节氮素迁移浓度,结果表明,次降雨量介于16.8~51mm的暴雨过程中,流域出口处的径流过程曲线呈单峰状态,且峰值滞后于最大雨强,滞后时间因降雨强度的不同而不同;3场暴雨事件的综合径流系数达0.059;总氮迁移量为38.79~197.53g/hm2,铵态氮和硝态氮是氮素迁移的主要类型,而且硝态氮的平均迁移量大于铵态氮;结合态氮是氮素迁移的主要类型,占总氮输出的75.18%~98.01%;总氮、硝态氮和铵态氮平均浓度随时间呈现出夏季〉秋季〉春季〉冬季的规律。The watershed scale experiments were conducted to research the characteristics of nitrogen losses with surface runoff in the conditions of rainstorm.Results showed that the change of surface runoff hydrograph usually appeared in single-peak form.Generally,the peak of surface runoff lagged behind the maximum rainfall intensity,but the lagged time had big difference because of the conditions of rainfall,when the precipitation was within 16.8~51mm.The comprehensive runoff coefficient of the three rainstorms was0.059.Under rainstorm conditions,the transport fluxes of total nitrogen was within 38.79~197.53g/hm2,and nitrate nitrogen and ammonium nitrogen accounted for the main transported forms.Absorbed nitrogen was the main export form of total nitrogen.And absorbed nitrogen accounted for 75.18%~98.01%of total nitrogen.The concentration of total nitrogen,nitrate nitrogen and ammonium nitrogen presented a same regular pattern in which the sequence decreasingly was summer,autumn,spring and winter.

关 键 词：岔口小流域 暴雨 地表径流 氮素迁移 

分 类 号：X522[环境科学与工程—环境工程] S157[农业科学—土壤学]