重庆市农业面源污染测算与空间特征解析

文章采用清单分析法对重庆市农业面源主要污染物、污染负荷进行估算,在此基础之上,运用聚类分析、线性回归以及实证调研等方法,对污染的空间分布特征、影响因素、污染成因作测算与分析。研究尺度定位区县级空间,研究范围依从经济功能区域划分,囊括重庆市37个农业区县。重庆市平均水质污染物浓度COD为11.995mg/L,TN为2.043mg/L,TP为0.457mg/L,综合水质指数为1.989,在轻度污染范围内,非常接近中度污染。重庆主城区周围的农业面源污染严重,两翼地区污染较轻。秸秆、畜禽粪便、化肥是污染的三大主源头,贡献率依次为44.65%,45.47%,7.23%。聚类分析表明永川、荣昌、铜梁、大足、长寿、璧山等区县的污染非常严重。农村用电量、农作物播种面积、地表水资源总量对污染负荷指标具有强烈影响。在污染负荷空间特征分析及实证调研基础之上,提出相应的治理对策建议。

MEASUREMENT AND SPATIAL FEATURE ANALYSIS OF AGRICULTURAL NON-POINT SOURCE POLLUTION IN CHONGQING

This paper calculated the main source, pollution load of agricultural non-point source pollution in Chongqing using list analysis method, and then analyzed influencing factors, spatial distribution characteristics, and pollution causes using clustering analysis, linear regression and empirical research. The scale of the research was based on the county level, and the scope of study was in line with the regional division of economic function, which included 37 agricultural districts and counties of Chongqing. The results showed that among the average water pollutant concentration, the COD was 11.995 mg/L, TN was 2.043 mg/L, and TP was 0.457 mg/L, the comprehensive water quality index was 1.989, which was within the scope of the light pollution and very close to the moderate pollution. The agricultural non-point source pollution around downtown was serious. Straw, excrements of livestocks, and chemical fertilizer were the main sources of pollution, which contributed 44.65%, 45.47%, 7.23%, respectively. Cluster analysis showed that the pollution in Yongchuan, Rongchang, TongLiang, Dazu, Changshou, Bishan county was very serious. Rural electricity consumption, crop planting area and total surface water resources had a strong influence on the pollution load. On the basis of the analysis of the pollution load spatial feature and the empirical investigation, the corresponding countermeasures and suggestions were put forward.