Analysis Of The Spatial And Temporal Characteristics And Influencing Factors Of Agricultural Non-Point Source Pollution In Heilongjiang Province

The control of agricultural non-point source pollution is an important premise to realize the green development of agriculture,the key to the reform of agricultural supply side,and the important work of agricultural modernization development in Heilongjiang Province.In the context of rural revitalization and agricultural green development,the quality of agricultural non-point source pollution control determines whether clear waters and lush mountains can be turned into gold and silver mountains,and whether a solid foundation can be laid for rural industry revitalization.As a major agricultural province,Heilongjiang bears the political responsibility of safeguarding national food security.The reuse and light cultivation mode formed for a long time,behind the agricultural intensification,the application of high-intensity chemical fertilizers and pesticides leads to agricultural non-point source pollution.In this context,exploring the temporal and spatial characteristics and influencing factors of agricultural non-point source pollution in Heilongjiang Province has important research significance in promoting agricultural green transformation and high-quality development,and can provide decision-making basis for relevant departments.Taking data accessibility and the completeness of spatio-temporal comparative analysis into consideration,this paper took the cities of Heilongjiang Province as the research unit and calculated the emissions of agricultural non-point source pollution in Heilongjiang Province from 2001 to 2020 by using the pollutant discharge coefficient method,and explored the spatio-temporal evolution characteristics of agricultural non-point source pollution in Heilongjiang Province through comprehensive statistical analysis and GIS spatial analysis.Using STIRPAT(Stochastic Impacts by Regression on Population,Affluence,and Technology)environmental impact assessment model,the stochastic impacts by regression on population,Affluence,and technology are used to analyze the spatial-temporal evolution of agricultural non-point source pollution.To explore the occurrence rules of agricultural non-point source pollution,and provide decision-making support for relevant departments to prevent and control agricultural non-point source pollution and agricultural sustainable development.The main conclusions are as follows:(1)In terms of time dimension,the discharge of COD,TN and TP showed an increasing trend from 2001 to 2014,but there was a sudden decline in 2006,because the quantity of livestock and poultry breeding in Heilongjiang Province was greatly reduced in 2006.From 2014 to 2019,there was a gradual decline,but in 2020,the emissions of the three pollutants rose again,because the amount of livestock and poultry breeding in Heilongjiang Province increased significantly in 2020 compared with previous years.(2)Spatial dimension: on the whole,agricultural non-point source pollution in Heilongjiang Province was > in the south > in the north,in the west > in the east,which was directly related to the topography and industrial layout of Heilongjiang Province.The northern and eastern parts of Heilongjiang Province are mainly the large and small Hinggan Mountains,with land use and forest land as the main areas,while the agricultural industry mainly accumulates in the southwest plain,such as Harbin,Suihua,Qiqihar,etc.Suihua City is the most serious area of agricultural non-point source pollution in Heilongjiang Province,which needs to be focused on and control measures should be taken.(3)Pollution source dimension: livestock and poultry breeding is the main source of agricultural non-point source pollution in Heilongjiang Province,accounting for 80% of the total agricultural non-point source pollution emission.The pollution sources of planting industry accounted for less than20% of TN and TP pollutants.Aquaculture accounts for only 1%-2% of non-point source pollution in agricultural production.(4)The analysis results of influencing factors of agricultural non-point source pollution show that the emission of agricultural non-point source pollution will increase when the rural population increases,the regional economic development level improves,the proportion of agricultural economy in the economic structure increases,the proportion of animal husbandry in the agricultural structure increases,and the proportion of food crops in the planting structure decreases.(5)According to the above analysis results,this paper proposed optimization measures to reduce agricultural non-point source pollution emissions in Heilongjiang Province from the aspects of optimizing agricultural structure according to local conditions,adopting financial ecological compensation measures,rationally promoting the adjustment of planting structure layout,promoting clean livestock and poultry production and ecological industrial mode.