2005～2014年苏州市农业面源污染源强变化特征

Temporal Variation Characteristics of Agricultural Non-point Source Pollution in Suzhou from 2005 to 2014

利用清单分析的方法,对2005~2014年苏州市农业面源污染排放量进行了计算,分析该地区农业面源污染源强的时间变化特征。研究结果表明,2014年苏州市农业面源污染化学需氧量(COD)、氨氮(NH4+-N)、总氮(TN)和总磷(TP)的排放总量分别为131 843.8 t、6 150.2 t、20 848.5 t和2 922.8 t,属于畜禽养殖型和农村生活双重污染区。而近十年苏州市农业面源污染总体呈现逐年下降趋势,较2005年分别降低38.40%、21.80%、17.13%和25.26%。同时,选用等标污染负荷法分析了苏州市的农业面源污染风险,按照污染物等标排放量TN>TP>COD,而按照行业等标排放量畜禽养殖>农村生活>种植业>水产养殖。近十年苏州市农业面源污染等标污染排放量从554.1亿m^3降至420.6亿m3,降低24.09%,污染风险降低。随着工业经济的逐年提升,苏州市农业面源污染排放量逐渐下降,但农业面源污染风险依旧存在,TN污染风险最高,且污染来源复杂,应加强各行业的协同减控。

The temporal variation characteristics of agricultural non-point source pollution in Suzhou City were analyzed by inventory analysis from 2005 to 2014. Results indicated that Suzhou was seriously polluted by livestock breeding and rural living in agricultural non-point source pollution. And the absolute real discharges of COD, ammonium, TN and TP from which was 13 1843.8 tons, 6 150.2 tons, 20 848.5 tons and 2 922.8 tons in 2014, respectively. However, the pollutant discharge of agricultural non-point source pollution in Suzhou decreased obviously in the recent ten years. Compared to 2005, the pollutants decreased by 38.40%, 21.80%, 17.13% and 25.26% in 2014, respectively. As mean time, the pollution risk was evaluated with equivalent pollution load method of water quality. The results indicated the equivalent pollutant load of in Suzhou was TN〉TP〉COD in turn, as while the industry resource was livestock breeding〉rural living〉plant〉aquaculture successively. Also, the total equivalent pollution load changed from 554.1 billion m3 to 420.6 billion m3 and declined by 24.09% in recent ten years. The agricultural non-point source pollution discharge was gradually declined in Suzhou along with the industrial economy increased year by year. However, the risk of agricultural non-point source pollution was still existed with the highest pollution risk of TN. Therefore, the pollutant source control of all the agricultural industries should be strengthened in the future.