广西农业面源污染时空演变及其防控对策
Spatial-temporal evolution of agricultural non-point source pollution in Guangxi and its prevention and control countermeasures
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摘要: 【目的】分析广西农业面源污染的时空演变规律,提出治理农业面源污染的防控对策,为广西农业面源污染防控、实施乡村振兴提供理论依据。【方法】以西江经济带、桂西资源富集区和北部湾经济区为研究单元,构建农田化肥和畜禽养殖粪便污染清单,采用单元调查法测算2008—2019年广西农业面源污染物排放量和排放强度。【结果】农业面源污染地区及其污染物的区域分布尚未发生变化,西江经济带是污染物排放总量和强度增长的主要区域。各区域污染物排放结构及其强度结构的变化差异较大。从污染物排放强度结构来看,西江经济带由化学需氧量(COD)向总氮(TN)扩大,北部湾经济区由TN向COD扩大,桂西资源富集区尚未发生明显变化,依然为TN。从污染物排放强度结构来看,西江经济带从COD向COD和TN转变,桂西资源富集区从TN向COD和TN转变,北部湾经济区从TN向COD转变。经济作物种植规模的扩大与生猪养殖量的增长是各区域污染物排放结构及其强度结构性变化的主要原因。【建议】提高农业科技水平、发展规模化养殖、加强农业教育培训和增加农村污染治理投入。Abstract: 【Objective】To analyze the spatial-temporal evolution law of agricultural non-point source pollution in Guangxi,and to put forward the prevention and control countermeasures to control agricultural non-point source pollution,so as to provide theoretical basis for the prevention and control of agricultural non-point source pollution in Guangxi and the implementation of rural revitalization policy.【Method】The Xijiang Economic Belt,resource-rich area in western Guangxi and Beibu Gulf Economic Zone were taken as research units. A list of farmland chemical fertilizers and livestock and poultry manure pollution was made,and the unit survey method was used to calculate the amount and intensity of agricultural non-point source pollutant emission in Guangxi from 2008 to 2019.【Result】The agricultural non-point source polluted areas and the pollutant regional distribution had not changed,and the Xijiang Economic Belt was the main area where the total amount and intensity of pollutant emission increased. The changes in pollutant emission structure and intensity structure of different regions were quite different. Seem from the structure of pollutant emission,the Xijiang Economic Belt had expanded from chemical oxygen demand(COD)to total nitrogen(TN),and the Beibu Gulf Economic Zone had expanded from TN to COD. The resource-rich area in western Guangxi had not changed significantly and was still TN. Seem from the structure of pollutant emission intensity,in the Xijiang Economic Belt,COD changed to COD and TN,and the resource-rich area in western Guangxi changed from TN to COD and TN,and the Beibu Gulf Economic Zone changed from TN to COD. The expansion of the scale of commercial crops and the growth of pig breeding were the main reasons for the structural changes in the structure and intensity of pollutant emissions in various regions.【Suggestion】The level of agricultural science and technology level should be improved. Large-scale breeding should be developed. Agricultural education and training should be strengthened,and investment in rural pollution control should be increased.