沙颍河河南段农村面源污染负荷特征与解析

Characteristics and Analysis of Rural Non-point Source Pollution Load in Henan Section of the Shaying River

为了准确评估沙颍河上游河南省郑州、平顶山、许昌、漯河和周口5地市区域内的农村面源污染负荷,采用输出系数法,以总氮(TN)、总磷(TP)为指标计算了农业种植业、畜禽养殖业、农村生活3类农村面源污染排放量和贡献率,分析了TN、TP污染负荷的时空分布特征;并以种植面积、粮食需求和污染负荷控制为约束条件构建了区域内农业种植业结构优化模型。结果表明,沙颍河上游河南五地市2009—2018年,TN、TP污染负荷量呈减少趋势,且十年内分别减少2万t和0.3万t。5地市的3类农村面源污染中,TN负荷量贡献率:农业种植>农村生活>畜禽养殖,TP负荷量贡献率:农业种植>畜禽养殖>农村生活,其中周口市贡献率最大。农业种植业优化结果显示,规划末期粮食作物播种面积增加5.93万hm^(2),经济作物播种面积增加2.50万hm^(2),TP排放负荷约束是经济作物种植规模增长的主要限制因素。研究结果可为区域内的农村面源污染的防控和治理提供科学依据。

In order to accurately assess the rural non-point source pollution load in the five cities of Zhengzhou,Pingdingshan,Xuchang,Luohe and Zhoukou in Henan Province,in the upper reaches of the Shaying River,this paper adopted the output coefficient method to calculate emissions and contribution rate of the total nitrogen(TN)and total phosphorus(TP)from three types of rural non-point source pollution:agricultural planting,livestock and poultry breeding,and rural life,and analyze the temporal and spatial distribution characteristics of TN and TP pollution loads.Meanwhile,with the planting area,food demand and pollution load control as constraints,a regional agricultur⁃al planting industry structure optimization model was constructed.The results showed that the pollution load of TN and TP showed a decreasing trend from 2009 to 2018,and the pollution load was reduced by 20,000 tons and 3,000 tons respectively.Among the three types of rural non-point source pollution,the contribution rate of TN load from high to low is:agricultural planting,rural life,livestock and poultry breeding.And the contribution rate of TP load from high to low is:agricultural planting,livestock and poultry breeding,rural life.Zhoukou City had the largest con⁃tribution rate.The optimization results of the agricultural planting industry showed that the sown area of grain crops increased by 59,300hm^(2),and the cash crops increased by 25,000hm^(2).TP emission load restriction was the main fac⁃tor in the growth of economic crop planting scale.The research results can provide basic support and guiding signifi⁃cance for the prevention,control and governance of rural non-point source pollution in the region.