基于排水沟的宁夏银北灌区农田退水污染演变研究  

Evolution of drain-based research of irrigation return flow pollution in Yinbei Irrigation Area

作　　者：杨丽慧[1,2] 王少丽[1,2] 阮本清[1] 管孝艳[1,2] 

机构地区：[1]中国水利水电科学研究院,北京100048 [2]国家节水灌溉北京工程技术研究中心,北京100048

出　　处：《中国生态农业学报》2015年第12期1580-1587,共8页Chinese Journal of Eco-Agriculture

基　　金：水利部公益行业科研专项(201401001;201401019)资助~~

摘　　要：2000年以来宁夏引黄灌区引水量不断下降,为探究引水量下降对农田退水污染的影响,以银北灌区为研究对象,选择灌区两条典型排水沟——银新沟和第五排水沟,揭示其退水量与污染来源年内分布规律,基于水文统计分析方法探讨灌溉期水质氨氮和总磷的演变及其污染负荷年际变化特征,分析引水量下降对灌区农田退水污染的影响。结果表明:排水沟流量过程与引水过程具有很好的一致性,且农田退水污染主要发生在灌溉期;引水量减少以来,银新沟和第五排水沟退水量显著下降,灌溉期水质有所改善,与2004年以前相比,银新沟农田氨氮、总磷污染负荷消减率分别为35.3%和41.7%,第五排水沟相应为71.2%和63.7%。两沟农田污染负荷与退水量间存在较为显著的正相关。分析得出控制灌区引水量,实施农业节水对防治农田退水污染具有积极作用。Diverted water volume from the Yellow River to Ningxia irrigation area has continued to drop since 2000, having a significant impact on the development of irrigation in Ningxia. In order to determine the effect of decreasing diverted water volume on pollution of irrigation return flow in the region, the Yinbei Irrigation Area comprising of two typical drains（Yinxin and the Fifth drains） was used as a case study. Firstly, the yearly regularity of the amount of farmland irrigation return flow and the sources of pollution in the Yinxin and Fifth drains were determined. Furthermore, the evolution of ammonia nitrogen and total phosphorus concentrations during irrigation period in the drains were analyzed using the Mann-Kendall method. Meanwhile, farmland pollution load was calculated using a hydrology statistical analysis method. Finally, the effect of the decrease in water diversion on pollution of irrigation return flow in Yinbei Irrigation Area was analyzed and discussed. The results showed that the discharge processes in the drains were consistent with water diversion processes in the irrigation area, while irrigation return flow pollution mainly occurred in the stage of irrigation. Since 2000, the amount of irrigation return flow fell significantly in the Yinxin and Fifth drains. This change was largely in line with the diverted water volume from the Yellow River to the irrigation area. Furthermore, the water quality of irrigation return flow was improved during irrigation period in the Yinxin and Fifth drains. For the Yinxin drain, the concentration of total phosphorus apparently decreased and the concentration dynamics of ammonia nitrogen stabilized during irrigation period.Similarly, there were decreasing trends in the concentrations of ammonia nitrogen and total phosphorus in the Fifth drain during irrigation period. Compared with the period prior to 2004, ammonia nitrogen and total phosphorus load in the Yinxin drain dropped respectively by 35.3% and 41.7%, while that in the Fifth drain dropped by 71.2%

关 键 词：银北灌区 引水量 排水沟 农田退水 面源污染 污染负荷 

分 类 号：X52[环境科学与工程—环境工程]