改进的输出系数法在农业污染源估算中的应用

Application of improved Export Coefficient Model in estimation of agricultural source pollutant

农业污染源是非点源污染的重要来源,了解农业污染源现状是研究流域非点源污染的前提.该文考虑了降雨和地形特征对污染物迁移的损失,并给出了降雨与地形特征对流域农业源污染损失系数的确定方法,研究了改进的输出系数模型.将改进的输出系数模型应用于鄱阳湖流域的4个小区域内,并分别计算4个小流域的降雨和地形特征影响因子,对各种污染物输出系数进行率定和验证,使改进后的输出系数模型更符合农业源污染物运动机理,通过计算发现,部分模拟精度有所提高,并得到了一组适合鄱阳湖流域农业源非点源污染物的输出系数,将其应用到整个鄱阳湖流域的农业源污染物的快速估算,为鄱阳湖流域非点源污染控制提供了科学依据.

Agricultural source pollutant is an important source of non-point source pollutant,which is the basis of estimate of non-point source pollutant in watershed.The paper improved Export Coefficient Model（ECM） considering the effect of precipitation and terrain on pollutant transport.Firstly,the estimation method of loss coefficients of agricultural source pollutant influenced by precipitation and terrain factors are introduced.The ECM is employed to apply in the four basins in Poyang Lake watershed to compute the precipitation and terrain factors.Then,the export coefficients for the pollutants are calibrated and validated after estimating the precipitation and terrain factors.The improved ECM is more reasonable for agricultural source transport mechanism.The accuracy of most modeling results is improved after carrying out the experiment.Finally,a group of export coefficients for various pollutants are obtained and applied to quickly estimate the agriculture source pollutant load in the whole Poyang Lake watershed,which can scientifically support the non-point source pollution control in Poyang Lake watershed.