吉林省西部新增灌区水田非点源污染负荷估算

吉林省西部实施土地整理和引水工程新增水田1.53×105ha,同时暴露了以T-N、T-P和总盐量为特征污染物的严重的农田非点源污染问题。应用美国通用土壤流失量方程(USLE)和美国农业非点源管理与化学径流模型(CREAMS),结合典型流域单元试验农田连续监测,估算了吉林省西部地区盐碱地改水田新增非点源污染物TN、TP和总盐量年输出负荷。研究表明:吉林省西部新增水田非点源污染物输出总负荷:氮素4 029.561 t/a(26.337 kg/ha),磷素1 407.982 5 t/a(9.242 5 kg/ha),总盐分851 537.871 t/a(5 565.607kg/ha)。按照驱动作用力分析,降雨径流与农田排水共同驱动水田氮素流失,降雨径流是磷流失主要驱动力,田间排水是总盐分流失主要驱动力。

Estimation on Pollution Load of Added Non-point Source Pollution from Paddy Fields in Western Jilin Province

Against the background of land arrangements and diversion projects,an area of 1.53×105ha farmland have been explored in the west of Jilin Province,which has brought non-point source pollutions consisting of T-N,T-P and total salts.Model USLE and CREAMS,with monitoring on the typical testing farmland have been used to estimate the added load of non-point pollutants T-N,T-P and total salts yearly from the saline and alkali land exploited to farmland in the west of Jilin Province.The results show that T-N 4 029.561t/a（26.337kg/ha）,T-P 1 407.982 5t/a（9.242 5kg/ha）and total salts 851 537.871t/a（5 565.607kg/ha）have been discharged in the drainage.Based on the analysis of the driven forces,the runoff of rainfall and the drainage of farmlands are the two major factors impacting the T-P and total salts output respectively and both of them have effects on the load of T-N.