丹江口库区典型小流域地表径流氮素动态变化  

DYNAMIC CHANGE RESEARCH OF NITROGEN LOSS FROM SURFACE RUNOFF IN THE TYPICAL SMALL WATERSHED OF DANJIANGKOU RESERVOIR AREA

作　　者：涂安国[1,2] 尹炜[2] 陈德强[1] 叶闽[2] 雷阿林[2] 

机构地区：[1]河海大学环境科学与工程学院,江苏南京210098 [2]长江水资源保护科学研究所,湖北武汉430051

出　　处：《长江流域资源与环境》2010年第8期926-932,共7页Resources and Environment in the Yangtze Basin

基　　金：国家科技支撑计划项目(2006BAC10B02)

摘　　要：探明面源污染特征对制定丹江口水库水质保障体系具有重要意义。以胡家山小流域为研究对象,对村落和林-耕复合两种典型土地利用类型和流域各集水区出口地表径流氮浓度进行了连续监测。结果表明:村落降雨径流中总氮、硝态氮浓度较高,其中总氮均值超过20mg/L,变化幅度都不大;氨氮浓度较低,但变化剧烈,这种氮浓度演变过程和降雨强度关系密切。硝态氮是村落氮输出的主要形态,占总氮输出的60.31%～96.55%,与总氮输出变化过程具有显著的相关性。林-耕地的氮浓度相对较低,总氮表现出上升—下降—平稳—上升的变化过程,硝态氮和总氮变化有着显著的相关性。在空间传输过程中,小流域下游氮浓度表现出稀释和富集两种效应,其中村落的氮输出对两种效应影响较大;在时间上,受耕作制度和气象变化,各集水区的氮浓度季节性变化明显,总氮浓度表现出春季>夏季>秋季>冬季,硝氮浓度表现出秋季>夏季>春季>冬季。胡家山小流域径流中氮素的含量均高于水库水体氮素含量,总氮高于地表水Ⅴ类水质标准,需要加强对小流域污染源的控制与处理,尤其是对村落径流的处理。Non-point source pollution is one of the most important factors affacting the water quality of Danjiangkou Reservoir.In order to explore the variation of non-point source pollution,nitrogen concentrations were measured from January to December of 2008within different types of land use and small watersheds in Hujiashan.The results showed that TN and NO3-^-N concentrations were high and steady;While NH4＋N concentration was low,but fluctuated greatly in village.The dynamic process of nitrogen concentrations at the outlet of village was closely related to rainfall intensity.NO3-^-N was the main form of nitrogen loss,accounting for 60.31% ～96.55%of TN output,and it was correlated significantly with TN.Compared with nitrogen concentration in village,the concentrations of nitrogen was low in mixture of woodland and farmland,and TN showed a process from increase to decrease,and then from smooth to increase change with rainfall,and NO3-^-N and TN had a close relationship.From the saptial transporting,the concentration of nitrogen showed dilution and enrichment effects in the downstrean of small watersheds,while the village concentration of nitrogen had large effect on these two types.In temporal,the concentration of NO3-^-N and TN varied with season change,showing concentration of TN in spring〉summer〉autumn〉winter,NO3-^-N in autumn〉summer〉spring〉winter,which was closely related to agricultural systems and weather.The water quality of Hujiashan watershed was poorer than that of Danjiangkou Reservoir;thus the effective measures should be implemented to improve the water quality,especially in villages.

关 键 词：丹江口库区 地表径流 面源污染 氮 

分 类 号：S157[农业科学—土壤学]