汾河灌区农业面源污染经验统计模型的构建与验证

以山西省汾河平原灌区为研究区,根据2004—2008年灌区小店桥和义棠2个水文控制站有限的、离散的径流量和污染物浓度月监测值,采用河流污染物时段通量法分别计算2站点河道断面的总氮(TN)和总磷(TP)年通量,得到灌区TN和TP年负荷量;采用传统输出系数法确定了同期灌区农业种植、农村人口和畜禽养殖等污染源的TN和TP输出量。由此确定了灌区TN和TP迁移过程中的流域损失系数,建立了流域损失系数和年径流模数的非线性关系;构建了包含各类污染源数量、输出系数和年径流模数的灌区农业面源污染经验统计模型;用该模型模拟了2009—2010年灌区的TN和TP负荷量,与实测值相比误差均小于40%,满足精度要求。所建模型适合用于我国平原灌区面源污染负荷的估算和预测。

Construction and verification of an empirical model for agricultural nonpoint source pollution in the Fenhe irrigation district

Taking the Fenhe plain irrigation district as the study region, yearly flux of total nitrogen(TN) and total phosphorus(TP) from 2004 to 2008 was calculated by period pollutant load flux methods based on the data measured from hydrologic stations in Xiaodianqiao and Yitang.TN and TP emissions from agricultural cultivation, livestock farming and rural life were estimated from the information in the district;watershed loss coefficients of TN and TP were determined, and then a non-linear relationship between watershed loss coefficients and runoff modulus was created.Finally, an empirical model for agricultural non-point source pollution was constructed in the Fenhe Irrigation District.The model was applied to estimate TN and TP load in years 2009 and 2010.Relative errors (RE) of TN and TP between simulated and measured values were all within 40%, which are acceptable for model assessment.