Non-Point Source Pollution And Environmental Behavior Of Farmers In The Water Source Area Of The Middle Route Of The South-to-north Water Diversion Project

With the economic development and population growth,red tide and algae bloom in rivers,lakes and coastal waters frequently occur as a characteristic feature of the eutrophication of water bodies worldwide,and water pollution has become a topic of concern.The South-to-North Water Diversion Project is the world's largest cross-basin diversion project.The Middle Route was completed in 2014,and water has been transferred to North China by 9.5 km~3/year.At present,100%of the main urban residents in Tianjin and73%of those in Beijing use water supplied through this project,directly benefiting more than 53 million people.Due to the construction of the South-to-North Water Diversion Project,the ecological and economic construction problems caused by the shortage of water resources have been effectively alleviated in northern China.To ensure that the“clear water of the river runs into the reservoir and that the clear water of the reservoir is sent to the north”,the environmental protection of the water source area is the precondition for the smooth operation of the project.Water pollution sources include point source pollution and non-point source pollution.Recently,point source pollution significantly reduced through the implementation of systematic laws,standards and comparatively high-quality engineering measures.Meanwhile,non-point source pollution has become a leading source of water pollution that is difficult to control.As a major source of water pollutants,non-point source pollution is diffuse,prone to pulse-discharges,and difficult to trace to any single pollution event or source.The water source area of the middle route of the south-to-north water diversion project(WSA)is located in the Qinba Mountain Area.Most of the counties are concentrated contiguous poverty areas,and the agricultural production and living areas are concentrated in the river valleys where the rivers pass through the area.Therefore,study the relationship between both environmental construction with economic construction and the land-use/land-cover(LULC)is crucial to control agriculture non-point source pollution.The environmental behavior of farmers plays an important role in exploring the causes of non-point source pollution and taking scientific control and management measures.WSA is located in the north-south climate transition zone of China,and it is also the transition zone of vegetation,soil,farming system,production and life style in China.The farmers here have somewhat strong representation of the status quo of the entire Chinese farmers.Therefore,studying the environmental behavior of farmers has an important role in the management of agricultural non-point source pollution in WSA and China.Under the background of implementing the fight against poverty and rural revitalization strategy,President Xi Jinping emphasized that it is necessary to explore a new path of high-quality development that prioritizes ecology and highlights green development.At present,China's agriculture and country are in the process of modernization.How to coordinate the relation between both agricultural non-point source pollution with economy,industry and LULC,and through certain methods of intervention,make environmental behavior of farmers develop towards environmentally friendly development which are crucial to control and management agricultural non-point sources in WSA.Based on the previous studies,according to panel data modeling,structural equation modeling,and other methods,this study first reviews the spatio-temporal characteristics of the agricultural non-point source pollution and safety threshold,and then analyzes the relationship between both agricultural non-point source pollution with farmers'economic income and industrial development from the macroscopic perspective,and studies the relationship between LULC landscape pattern and water quality of small watershed.Finally,the environmental behavior of farmers is taken as the research object,and the influencing factors are studied.The main research contents and results of this study are as follows:(1)Based on the environmental inventory method,the study recognizes and grasps the current situation and spatio-temporal characteristics of agricultural non-point source pollution in WSA.In 2003,the total nitrogen(TN)and total phosphorus(TP)loads of agricultural non-point source pollution were 61,000 tonnes and 16,000 tonnes respectively,which were 72,000 tonnes and 23,000 tonnes respectively in 2016,an increase of 19.1%and43.0%respectively.In terms of pollution load composition,chemical fertilizer is the main source,accounting for more than 60%of TN/TP loads,followed by rural life and livestock farming,agricultural wastes and aquaculture accounting for the lowest proportion,but the proportion of aquaculture has Increased in recent years.In terms of pollution intensity,the high pollution density areas are mainly concentrated in the Xixia,Xichuan and Shiyan in the reservoir area.As the main source of agricultural non-point source pollution,this paper evaluates the pollution of chemical fertilizer application and livestock farming based on models of fertilization environmental safety threshold and early warning analysis of livestock farming environmental safety in WSA.The results showed that the average application rate of chemical fertilizers was 443 kg/ha in WSA,which was slightly higher than the national fertilizer application rate.However,the average fertilizer safety threshold for WSA is 196kg/ha,and the fertilizer application rate in most counties is higher than it.And the fertilizer excessive and much excessive fertilization areas are mainly concentrated in the river crossing areas and the reservoir area;The pollution of livestock farming mainly comes from pigs and cattle.The proportion of pollution in sheep is low.Poultry,except for Danjiangkou City,is lower in other counties.The areas with large changes in livestock farming pollution are mainly concentrated in the Nanyang area,and the pollution of livestock farming is increasing during 2003-2009,but after 2009,the pollution is gradually decreasing.Livestock farming heavily polluted areas and more severe areas are also concentrated in the river crossing areas and the reservoir area,where nutrients are more accessible to reservoirs and pose a greater threat to water quality safety.(2)Through empirical methods,the relationship between agricultural non-point source pollution and farmers'economic income was studied.Found that the relationship between both farmers'economic income with TN load and pig equivalent pollution of livestock farming are typical inverted N-shaped Environmental Kuznet Curve(EKC).However,the relationship between both farmers'economic income with TP load and chemical fertilizer application were not typical EKC,which chemical fertilizer was N-shaped curve and TP load was linear.Furthermore,based on the 2003 constant price,the turning point are,approximately,1941.8 Yuan and 7299.2 Yuan for TN load,2372.1 Yuan and 3810.0 Yuan for chemical fertilizer,and 1651.8 Yuan and 5112.0 Yuan for livestock farming pollution.And by comparing with the 2016 constant price,the economic income of farmers in all counties exceeded the second turning point of chemical fertilizer and livestock farming pollution,but the second turning point of the TN load was only exceeded by Dengzhou,Xixia and Neixiang.(3)Analyzing the"decoupling"relationship between industrial development and agricultural non-point source pollution.The results showed that,except for some years in Shiyan and Dengzhou,primary industry experienced the weak negative decoupling and strong negative decoupling during 2004-2016 for TN load;For chemical fertilizer,farming industry of Neixiang,Ankang and Dengzhou experienced expansive coupling and expansive negative coupling,and others countries/cities experienced the weak negative decoupling during 2006-2016;For livestock farming,except for Shiyan,animal husbandry experienced the strong negative decoupling during 2006-2016 in WSA.The factors affecting agricultural non-point source pollution are decomposed by the Logarithmic Mean Divisia Index method(LMDI).The results showed that the main influencing factors of TN load are economic development effects,industrial structure effects and technical effects.Among them,economic development effects have positive impact on the increase of TN load,and the impact intensity is increasing,while the industrial structure effects and technical effects are negative.To influence,the effect of industrial structure on TN load reduction is gradually increasing,while the technical effects have significant effects in the early stage of research.The main influencing factors of chemical fertilizer are agricultural income effects,industrial structure effects and technical effects.On the whole,the agricultural income effects lead to an increase in the amount of chemical fertilizer applied,while the industrial structure effect and technical effect have the effect of reducing the amount of chemical fertilizer applied.The main influencing factors of livestock farming pollution are animal husbandry income effects and technical effects.The income effects of animal husbandry have positive impact on the aggravation of livestock farming pollution,while the technical effects have negative impact,and the effect of technological effects is relatively greater.(4)Based on the“source sink system theory”,the relationship between land landscape pattern of LULC and water quality in small watershed was studied.During the rainy season,the development of agricultural landscape as a“source”landscape has an intensifying effect on inorganic pollutants such as water quality TN,but the development of forest landscape as a“sink”has a slowing effect on inorganic pollutants,and the spatial accumulation of the landscape has the effect of reducing inorganic pollution.However,for organic pollutants such as COD,forest land and urban landscapes as“sources”,and the development of landscapes will exacerbate organic pollution of water quality.Although the proportion of urban area is small,the urban landscape has the greatest effect on organic pollution,and the accumulation of landscape will negatively moderate the effect of urban landscape on organic pollution,that is,the urban landscape with high fragmentation has a greater impact on organic pollutants.Different from the rainy season,the water pollution during the dry season is mainly affected by the point source pollution caused by the development of the urban landscape.(5)The environmental behavior of farmers plays an important role in exploring the causes of non-point source pollution and taking scientific control and management measures.Based on the theory of planned behavior(TPB),the study investigated the environmental behavior of farmers in the WSA.Results showed that TPB could explain farmers'environmental behavior and intention well.Furthermore,the farmers'attitude towards behavior,subjective norm,and perceived behavioral control positively and significantly influenced their environmental intention;their environmental intention further impacted their behavior.Subjective norm was proved to be the main key factor indirectly influencing the farmers'environmental behavior.Moreover,environmental knowledge following as a moderator,gender and age was used as control variables to conduct the environmental knowledge on TPB construct moderated mediation analysis.It demonstrated that gender had a significant controlling effect on environmental behavior;that is,males engage in more environmentally friendly behaviors.However,age showed a significant negative controlling effect on pro-environmental intention and an opposite effect on pro-environmental behavior.In addition,environmental knowledge could negatively moderate the relationship between Perceived behavioral control and environmental intention.Perceived behavioral control had a greater impact on the environmental intention of farmers with poor environmental knowledge,compared to those with plenty environmental knowledge.This study integrated the TPB which is diversely and extensively used across domains,and the protection motivation theory(PMT)which is frequently used in healthy studies to identify the main determinants of the environmental behavior and intention of farmers.Results indicate that use of the integrated model provides a better understanding of the environmental intentions of farmers than each component model when used individually.As with either TPB or PMT alone,the integrated model revealed that the subjective norms,attitudes,self-efficacies(i.e.,the perceived behavioral controls),and response efficacies of farmers positively and significantly influenced their intentions.On the other hand,response cost had a significantly negative effect.Among these factors,subjective norms were the most influential.However,unlike individual results obtained through PMT,the effects of perceived severity and vulnerability on the intentions of farmers were realized through the mediating effects of attitudes and subjective norms.The key determinant for the actual environmental behaviors of farmers was intention.There was also a significantly positive effect for self-efficacy.Managing and controlling agricultural agriculture non-point source pollution requires a multi-disciplinary and comprehensive approach.This study thus integrated TPB and PMT to gain insight into the environmental behaviors and intention of farmers.This provided a theoretical basis for NSP control.In general,based on the multidisciplinary theories and methods of economics,environmental science,sociology,geographic information science,etc.,this study studies the relationship between both economics,industry and LULC with agricultural non-point source pollution.And analyzes influencing factors of environmental behavior and develops a new model of farmer environmental behavior.The results of this study are intended to provide a theoretical basis for the scientific control of agricultural non-point source pollution and the rational intervention of farmers'environmental behavior in WSA.