| With the rapid development of agricultural economy in Jiangxi Province,the use of pesticides,fertilizers and other agricultural chemicals has been increasing year by year,the scale of livestock and poultry breeding has been expanding,and the problem of agricultural surface source pollution has become increasingly significant.Meanwhile,it is more difficult to monitor and prevent agricultural surface source pollution of non-point emissions compared with point source pollution of fixed emissions.Therefore,the problem of agricultural surface source pollution has become a research hotspot for scholars.This thesis focuses on agricultural surface source pollution in Jiangxi Province.Firstly,using the unit survey method,we estimate the pollution loads of total nitrogen(TN),total phosphorus(TP),and chemical oxygen demand(COD)generated by five types of pollution sources: agricultural fertilizer,fishery farming,agricultural solid waste,pastoral farming,and rural living in Jiangxi Province and each city from 2000 to 2021,and use The equivalence pollution load method was used to transform TN,TP and COD pollution loads into unified and comparable equivalence pollution loads,and then the equivalence pollution load intensity of Jiangxi Province and each city was calculated.Secondly,the GIS spatial analysis method and spatial autocorrelation analysis method were used to analyze the time-series change characteristics,spatial distribution characteristics and spatial autocorrelation of agricultural surface source pollution in Jiangxi Province.Finally,the STIRPAT model is used as the theoretical model,combined with the spatial Durbin model to analyze the effects of agricultural agglomeration,rural population size,agricultural structure,per capita gross regional product on agricultural surface source pollution,and three methods of replacing the spatial weight matrix,replacing the explanatory variables and eliminating extreme values are used for robustness testing.Around the above study,this thesis concludes that(1)during 2000-2021,the most important pollutant of agricultural surface source pollution in Jiangxi Province is TP,followed by TN.(2)The variation of agricultural surface source pollution in Jiangxi Province from 2000 to 2021 is large,ranging from-12% to 12%.(3)The agricultural surface source pollution in Jiangxi Province is characterized by high in the southwest and low in the northeast.(4)Agricultural surface source pollution in Jiangxi Province has a significant and relatively stable positive spatial correlation,with high pollution areas aggravating pollution in neighboring regions to a certain extent and low pollution areas mitigating pollution in neighboring regions to a certain extent.(5)Agricultural agglomeration has a significant negative influence on agricultural surface source pollution.The increase of agricultural agglomeration is conducive to the development of large-scale agricultural operations,promoting technical exchanges and division of labor between enterprises,improving the utilization rate of straw,livestock manure and other pollutants,and reducing the generation of agricultural surface source pollution.The number of rural population has a significant positive effect on agricultural surface source pollution,and the increase in the number of rural population will lead to an increase in pollutants generated by rural living and agricultural production activities.Agricultural structure has a significant negative effect on agricultural surface source pollution,indicating that an increase in the proportion of cultivation will reduce the degree of agricultural surface source pollution.The effect of per capita gross regional product on agricultural surface source pollution is not significant.By decomposing the effect of agricultural agglomeration on agricultural surface source pollution,we found that both local and neighboring regional agricultural agglomeration has a significant negative effect on local agricultural surface source pollution,that is,the increase of local agricultural agglomeration will not only reduce the degree of local agricultural surface source pollution,but also reduce the degree of neighboring regional agricultural surface source pollution,and has a greater effect on neighboring regional agricultural surface source pollution.Based on the above findings,this thesis makes recommendations to(1)strengthen joint prevention and control of agricultural surface source pollution in prefectures of Jiangxi Province to achieve win-win cooperation.(2)Encourage moderate scale operation of agriculture,promote the improvement of agricultural production efficiency and resource utilization rate,and reduce agricultural surface source pollution.(3)Appropriately adjust the structure of agriculture,use the mutually beneficial symbiotic relationship between organisms to reduce pollution from farming and improve ecological benefits.(4)To guide farmers to establish the idea of sustainable agricultural development,strengthen their awareness of environmental protection,and guide them to join in the management of agricultural surface source pollution. |
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