青海湖流域氮污染负荷空间分布特征及控制对策分析

Spatial Distribution Characteristics and Control Countermeasures of Nitrogen Load into Qinghai Lake Watershed

采用排污系数法估算了2016—2018年青海湖流域四县(共和县、天峻县、刚察县、海晏县)来自面源污染源(生活源、养殖业、种植业)总氮(TN)和氨氮(NH_(3)-N)入湖负荷。结果表明:青海湖流域入湖总氮负荷从2016年的2302.2 t N a,增加到2018年的2453.2 t N a;共和县、天峻县、刚察县和海晏县分别占总负荷23.0%~23.2%、21.7%~23.7%、36.6%~38.4%和15.2%~15.7%。入湖氨氮负荷从2016年的164.4 t N a,增加到2018年170.6 t N a;共和县、天峻县、刚察县和海晏县分别占总负荷17.3%~18.0%、21.7%~24.0%、49.1%~50.7%和9.6%~10.0%。总氮和氨氮入湖负荷均以养殖业占比最高。因此,应重点加强青海湖流域刚察县养殖业面源污染控制。建议通过优化养殖业空间布局,推广适度集约化养殖模式,推动粪污全量资源化,建设生态拦截带,防控粪氨挥发等举措控制青海湖流域养殖业对湖体氮输入。

The pollutant discharge coefficient method was used to estimate the load of TN and NH 3-N from non-point source sources(domestic sources,livestock,planting)into the Qinghai lake in four counties of Qinghai lake watershed(Gonghe County,Tianjun County,Gangchar County,Haiyan County)from^(2)016 to 2018.The results showed that the TN load in Qinghai lake watershed increased from^(2)302.2 t N a in 2016 to 2453.2 t N a in 2018;the Gonghe County,Tianjun County,Gangcha County and Haiyan County accounted for 23.0%~23.2%,21.7%~23.7%,36.6%~38.4%and 15.2%~15.7%of the total load,respectively.The NH 3-N load into lake increased from 164.4 t N a in 2016 to 170.6 t N a in 2018;the Gonghe County,Tianjun County,Gangcha County and Haiyan County accounted for 17.3%~18.0%,21.7%~24.0%,49.1%~50.7%and 9.6%~10.0%of the total load,respectively.The livestock breeding industry accounted for the highest load of TN and NH_(3)-N into lake.Therefore,it is important to strengthen the control of non-point source pollution of livestock in Gangcha County of Qinghai Lake watershed.It is suggested to optimize the spatial layout of livestock breeding industry,promote moderately intensive livestock breeding mode,promote full resource utilization of manure,construct ecological buffer belt,and reduction of ammonia volatilization from storage and disposal of manure for preventing nitrogen from Qinghai lake.