Reductions in non-point source pollution through different management practices for an agricultural watershed in the Three Gorges Reservoir Area

Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area （TGRA） of China. The Annualised Agricultural Non-Point Source Pollution （AnnAGNPS） model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice （CTP）, conservation reserve program （CRP） and conversion of cropland into forestland program （CCFP）. Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10° into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit.

Factor Analysis on the Factors that Influencing Rural Environmental Pollution in the Hilly Area of Sichuan Province,China

By using factor analysis method and establishing analysis indicator system from four aspects including crop production,poultry farming,rural life and township enterprises,the difference,features,and types of factors influencing the rural environmental pollution in the hilly area in Sichuan Province,China.Results prove that the major factor influencing rural environmental pollution in the study area is livestock and poultry breeding,flowed by crop planting,rural life,and township enterprises.Hence future pollution prevention and control should set about from livestock and poultry breeding.Meanwhile,attention should be paid to the prevention and control of rural environmental pollution caused by rural life and township enterprise production.

Study on the Control Model of Rural Non-point Source Pollution——Taking Ninghe County in Tianjin as an Example

[Objective] The aim was to study the control model of rural non-point source pollution.[Method] Taking Ninghe County(a typical agricultural county in Tianjin) as an example,the current development of local economy and society and characteristics of rural non-point source pollution were studied firstly,then the control model of rural non-point source pollution suitable for Ninghe County was constructed,and its environmental and economic benefits were analyzed finally.[Result] According to the sources of non-point source pollution,the control model of rural non-point source pollution in Ninghe County was divided into three modules from the aspects of planting industry,livestock raising industry and rural living.The main content of non-point source pollution control module of planting industry was composed of rational utilization of chemicals,water-saving irrigation,diversified utilization of straw etc.Non-point source pollution control module of livestock raising industry focused on the site selection of farm or raising zones,choice of raising mode,comprehensive utilization of livestock waste etc.In the non-point source pollution control module of rural living,villages were divided into two types(small town and ecological village) based on various geographical positions.In a word,these three modules were interrelated and targeted for non-point source pollution control in villages under different development situations.[Conclusion] The study could provide references for the rural non-point source pollution control in Hai River basin and other regions of Northern China.

Discussion on the Green Tax Stimulation Measure of Nitrogen Fertilizer Non-Point Source Pollution Control-Taking the Dongting Lake Area in China as a Case

A study on designing the tax of nitrogen fertilizer can provide a new method for controlling nitrogen fertilizer non-point source pollution. The tax design of nitrogen fertilizer was discussed by utilizing the external theory and the demand elasticity theory. The results indicated that the coefficient of price elasticity of nitrogen fertilizer demand is -0.21, which instructed that the market demand is in lack of elasticity in the short period and the impact of nitrogen fertilizer manufacturers is subtle. The 11 counties （cities and boroughs） in the Dongting Lake area in China, where the farmland nitrogen application surpassed the average ecological fertilization dosage, is listed to the taxation scope of nitrogen fertilizer tax. The environment loss will reduce 0.07 hundred million RMB yuan and the revenue will increase 0.89 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The loss, which was brought by the decreasing food supplies production, will be 0.58 hundred million RMB yuan and the net social benefit will be 0.38 hundred million RMB yuan following revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.49%. The variation scope of the income of farmers will range from -8.41 to 6.44%. The 5 areas, Yunxi Borough, Junshan Borough, Hanshou County, Jinshi City, and Ziyang Borough, had an increase in food supplies production after the revenue collection. The environment loss will reduce 0.01 hundred million RMB yuan and the revenue will increase 0.16 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The economic benefits, which was brought by the increasing cereals production, will be 0.67 hundred million RMB yuan and the net social benefit will be 0.84 hundred million RMB yuan after revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.06%. The variation scope of the increasing income of farmers will range from 0.69 to 6.44%. Considering the entire social welfare, taxation of nitrogen fertilizer will have more advantages than disadvantages in the Dongting Lake area.

Current Situation and Countermeasures of Water Body Pollution in Rural Areas of China

At present, people＇s environmental awareness gradually enhances, and the environmental requirements on production and living continuously improve. Urban sewage discharge management and sewage treatment intensity are increasing in whole country, and urban water environment has certain improvement. But in rural areas, due to relatively weak environmental awareness of residents, not high economic development degree and not perfect infrastructure construction, the issue has not been handled properly. It seriously restricts further development of rural economy, and contradiction between water pollution worsening and farmers eager to raise the level of living environment increasingly aggravating has become key problem restricting China＇s new rural construction. According to status quo of rural water pollution in China, causes and hazards of rural water pollu- tion are analyzed in detail, and several treatment suggestions are put forward.

The impacts of agricultural and rural economic policy system on agricultural non-point source pollution in China

Agricultural and rural economic policy system is one main driving force for the evolvement of agricultural Non-Point Source （NPS） pollution. In this paper, the main policies that influence agricultural NPS pollution are chosen, and a method to evaluate the impacts of agricultural and rural economic policy system on agricultural NPS pollution is brought forward. According to this, the questions about how and to what degree the policy system influence on agricultural NPS pollution are discussed.

Construction of the Control Mechanism of Rural Non-point Source Pollution in Nantong City

In view of the problems found in the in-depth interviews of the current situation of rural non-point source pollution control mechanism in Nantong City and their reasons,the following six countermeasures and suggestions are put forward,including giving full play to the role of fighting bastion of the Party branch and building a mechanism for Party building to lead the control of non-point source pollution in rural areas,giving prominence to the dominant role of farmers and establishing farmers’endogenous motivation excitation mechanism for rural non-point source pollution control,improving the interest coordination mechanism among multiple governance subjects and building a modern control system for rural non-point source pollution,combining regulations,administrative,economic,technical and other means of rural non-point source pollution control and strengthening the synergistic integration mechanism of multiple means of control,reconstructing the information disclosure mechanism of rural non-point source pollution control and building a comprehensive trust mechanism of multiple control subjects,and improving the mechanism for coordinating the supply of policy tools and ensure that basic mechanisms play their due role.

Investigation on Farmers'Willingness to Participate in Rural Non-point Source Pollution Control in Nantong and Analysis of Its Influencing Factors

Based on the questionnaire survey of 337 farmers in 8 villages in Rugao City,Jiangsu Province,the gender,age and educational level of the main able-bodied people of farm households,the characteristics of farmers’production and living behaviors,farmers’cognition of rural non-point source pollution,and farmers’willingness to pay for rural non-point source pollution control and its influencing factors were studied.The results show that to protect the rural ecological environment,most farmers are willing to participate in rural non-point source pollution control,but the annual cost of rural non-point source pollution control is low,and the number of volunteer days is small.Rural grass-roots party organizations should stimulate farmers’willingness to participate in rural non-point source pollution control,give full play to the role of the branch as a fighting fortress,and build a mechanism for Party building to lead rural non-point source pollution control.

Water Pollution Situation and Impacts in Rural China

With the development of national economics, water pollution is becoming a critical problem in rural China. This research presented a brief view of water pollution situation in rural areas of China in terms of water shortage, water-pollutant sources, eutrophication of water bodies and pollution development in temporal scale. Analysis was conducted on the negative effects of water pollution on human health, agricultural plantation and animal husbandry. Subsequently, some suggestions were proposed for wastewater treatment in rural areas.

Effects of livestock and poultry breeding pollution on health risks:Evidence from a hog breeding case in rural China

With the rapid development of livestock and poultry breeding industries,pollution problems caused by the discharge of wastewater and manure have become increasingly severe.However,studies on the impacts of this pollution on rural residents'health are lacking.Based on data from the Peking University's China Family Panel Studies in 2010 and 2014,this paper uses a cross-sectional and panel data probit model to estimate the probability of breeding industry development in rural areas increasing the health risks of local villagers.First,the study found that the more households engaged in breeding in the region or the larger the scale of regional breeding,the higher the health risks to local villagers,particularly in areas where pigs are raised.Second,compared with individual farming,the greater the proportion of large-scale farming,the higher the health risks to villagers.Third,the development of the breeding industry seldom includes the ecological recycling of wastes and fails to reduce the use of local pesticides and fertilizers,thereby increasing the health risks to villagers.Therefore,this paper argues that providing technology to process breeding industry waste and establish an organic industrial production chain will be crucial to reducing the impact of breeding industry pollution on human health.

Analysis of Rural Water Pollution Sources of Lushui Reservoir in Hubei Province

Pollution resulting from increased human activities is threatening the drinking water quality in China.Lushui Reservoir was selected as a typical example to represent polluted drinking water sources with rapid social economic development.This study analyzed the pollution load of Lushui Reservoir from rural areas by estimating the chemical oxygen demand(COD),ammonia nitrogen,total nitrogen and total phosphorus contributed by domestic sewage,agricultural activity,livestock breeding and aquaculture activity.Results show that the annual chemical oxygen demand,ammonia nitrogen,total nitrogen and total phosphorus loads in Lushui Reservoir were 180.44,22.99,33.15,and 3.99 t,respectively.The highest contribution to pollution load in all four aspects is domestic sewage,which was 89%,96%,82%,and 79%,respectively.Therefore,policies for sustainable development in the region should be directed primarily towards a reduction of domestic pollution.

Fractal Analysis on the Spatial Structure of Land Use Patterns in a Non-Point Source Polluted Area in Southern China

Based on the TM remote sensing interpretation of land use data of a non-point source polluted area in southern China in 2015, supported by ArcGIS and the fractal theory, this paper established the perimeter-area fractal equation of the spatial structure of land use types, quantitatively calculated the fractal dimension and stability index of various land use types in this non-point source polluted area in 2015, and analyzed the spatial structure characteristics of land use types. The results showed that the fractal dimension values of the different land use types in the research area ranged 1.141–1.657, and the whole fractal dimension of the research area was 1.206. To be specific, the fractal dimension values of unused land, grass land and rural residential land were high, and the fractal dimension values of dry land, paddy filed and waters were low, and the fractal dimension values of urban land, industrial traffic construction land and forest land were moderate. The area of the land use types whose stability index values were 0.2–0.4 accounted for 89.5% of total area, suggesting that the stability of the spatial structure of land use types of Beibei District in 2015 was not high generally. The rural residential land and urban land of the research area should be planned and managed more properly from now on.

Identification of the ＂source＂ and ＂sink＂ patterns influencing non-point source pollution in the Three Gorges Reservoir Area

Non-point source pollution is one of the primarily ecological issues affecting the Three Gorges Reservoir Area. In this paper, landscape resistance and motivation coefficient, which integrated various landscape elements, such as land use, soil, hydrology, topography, and vegetation, was established based on the effects of large-scale resistance and motivation on the formation of non-point source pollution. In addition, cost models of the landscape re- sistance and motivation coefficients were constructed based on the distances from the land- scape units to the sub-basin outlets in order to identify the ＂source＂ and ＂sink＂ patterns af- fecting the formation of non-point source pollution. The results indicated that the changes in the landscape resistance and motivation coefficients of the 16 sub-basins exhibited inverse relationships to their spatial distributions. The landscape resistance and motivation cost curves were more volatile than the landscape resistance and motivation coefficient curves. The landscape resistance and motivation cost trends of the 16 sub-basins became increas- ingly apparent along the flow of the Yangtze River. The landscape resistance and motivation cost models proposed in this paper could be used to identify large-scale non-point source pollution ＂source＂ and ＂sink＂ patterns. Moreover, the proposed model could be used to de- scribe the large-scale spatial characteristics of non-point source pollution formation based on ＂source＂ and ＂sink＂ landscape pattern indices, spatial localization, and landscape resistance and motivation coefficients.

Role of rural solid waste management in non-point source pollution control of Dianchi Lake catchments, China

In recent years,with control of the main muni-cipal and industrial point pollution sources and imple-mentation of cleaning for some inner pollution sources in the water body,the discharge of point source pollution decreased gradually,while non-point source pollution has become increasingly distressing in Dianchi Lake catch-ments.As one of the major targets in non-point source pollution control,an integrated solid waste controlling strategy combined with a technological solution and man-agement system was proposed and implemented based on the waste disposal situation and characteristics of rural solid waste in the demonstration area.As the key techno-logy in rural solid waste treatment,both centralized plant-scale composting and a dispersed farmer-operated waste treating system showed promise in rendering timely ben-efits in efficiency,large handling capacity,high quality of the end product,as well as good economic return.Problems encountered during multi-substrates co-com-posting such as pathogens,high moisture content,asyn-chronism in the decomposition of different substrates,and low quality of the end product can all be tackled.92.5% of solid waste was collected in the demonstration area,while the treating and recycling ratio reached 87.9%,which pre-vented 32.2 t nitrogen and 3.9 t phosphorus per year from entering the water body of Dianchi Lake after imple-mentation of the project.

Mechanism of nitrogen loss driven by soil and water erosion in water source areas

Nitrogen(N)present in drinking water as dissolved nitrates can directly affect people’s health,making it important to control N pollution in water source areas.N pollution caused by agricultural fertilizers can be controlled by reducing the amount of fertilizer applied,but pollution caused by soil and water erosion in hilly areas can only be controlled by conservation forests.The catchment area around Fushi Reservoir was selected as a test site and mechanisms of N loss from a vertical spatial perspective through field observations were determined.The main N losses occurred from June to September,accounting for 85.9-95.9%of the annual loss,with the losses in June and July accounting for 46.0%of the total,and in August and September for 41.9%.The N leakage from the water source area was effectively reduced by 38.2%through the optimization of the stand structure of the conservation forests.Establishing well-structured forests for water conservation is crucial to ensure the security of drinking water.This preliminary research lays the foundation for revealing then loss mechanisms in water source areas and improving the control of non-point source pollution in these areas.

DITCHES AND PONDS CAN BE THE SOURCES OR SINKS OF NON-POINT SOURCE POLLUTION:OBSERVATIONS IN AN UPLAND AREA IN THE JINGLINXI CATCHMENT,CHINA

As the common features of agroecosystems,ditches and ponds benefit the irrigation and drainage,as well as intercepting non-point source pollutants.However,most ditch-pond studies have been conducted in lowland areas.To test this source-sink assumption in upland areas,this study made observations on the ecological function of the ditch and pond system in a typical catchment in China.First,the changes in ponds in the catchment were analyzed using high-resolution remote sensing data.Then,the migration of agricultural pollutants in ditches and ponds were analyzed by field sampling and laboratory detection.The results showed that over the past 15 years the length of ditches in the catchment and the number of small ponds(<500 m2)have increased by 32%and 75%,respectively.The rate of change in nutrient concentrations in the ditches and ponds were mostly from-20%to 20%,indicating ditches and ponds can be both sources and sinks for agricultural pollutants.Lastly,the contributing factors were explored and it was found that ditches and ponds are important sinks in dry season.However,during the rainy season,ditches and ponds become sources of pollutants,with the rapid drainage of ditches and the overflow of ponds in upland areas.The results of this study revealed that the ditches and ponds could be used for ecological engineering in upland catchments to balance drainage and intercept pollutants.

舆论危机及其政府监管:边界与路径--以农村地区环境污染为考察对象

农村地区环境污染发生过程中,伴随着危言耸听、负面情绪传播、谣言、语言暴力等舆论危机现象。因此,要想解决农村生态危机、构建优良生态环境,在治理环境本身的基础上还需做好环境信息传播与舆论危机监管工作。研究认为,舆论监管是互联网监管背景下的必然选项,必须通过构建政府、行业、平台、公众等协同监管,为农村地区生态环境改善营造良好的舆论氛围。

黄河流域农业农村氮流时空分布特征及演化规律研究

氮磷等营养元素过剩引发的面源污染问题,是黄河流域水质恶化的重要原因.为应对黄河流域氮素危机,从源头上降低面源污染负荷,本研究基于物质流和空间分析方法,刻画1949-2022年间黄河流域农业农村氮流时空格局演化规律,评估黄河流域面源污染关键氮流和高风险区.结果表明:(1)新中国成立以来,黄河流域的作物收获量整体呈现上升的趋势,2015年之后在氮输入水平持续下降的情况下,仍然能够保持年均2%的增长,黄河流域在氮素利用水平上得到了极大的提升.(2)黄河流域农业农村依然存在严重的氮流失现象,其中存贮和反硝化是氮流失的主要部分,1962年、1992年和2022年这两部分流失量分别占耕地氮输出流的51%、47%和36%.2015开始氮素流失(存储)量逐年下降,2022年比2015年减少了15.55%,但是每年仍有30.12×10^(8)kg氮素流失到大气、水体和土壤中,是当年作物收获氮量的1.64倍,氮素损失率高达62.05%.(3)降雨和地势地形是影响氮径流的决定因素,在高风险区内约有27%~45%的氮剩余流失到附近的地表水中,主要分布在甘肃省的最南部和东南角部分地区、陕西省的最南部和山东省东部地区.研究显示:黄河流域在氮素利用提升和氮污染治理方面取得一定成效,但是仍然存在严重的氮流失现象;需要持续推进化肥减量、粪便还田和农村污水治理,同时需要在高风险区采取构建缓冲带等工程措施,才能实现面源污染等氮危机的有效控制.

我国西部农村地区固体燃料燃烧污染物排放因子测定及分布特征

排放因子是估算污染物排放量的重要参数,为获取可靠的、有区域特征的固体燃料排放因子,2018年在我国西部9个省/自治区利用稀释采样系统入户收集了226个固体燃料燃烧样本,获得了薪柴、秸秆和煤在不同类型炉具中燃烧排放CO_(2)、CO、OC、EC、PM_(2.5)的排放因子。结果表明:秸秆类较易燃烧的燃料有较高的OC、EC、PM2.5排放因子,煤有较高的CO_(2)、CO排放因子。炉灶类型对薪柴的OC、PM2.5的排放因子影响稍大,薪柴在炕中燃烧的OC、PM_(2.5)排放因子比在砖灶和铁炉高约2-3.1倍,但秸秆在不同炉具中的排放因子差异较小。受不同区域燃料和炉灶类型以及操作习惯差异的共同影响,排放因子呈现明显的区域性差异,高CO_(2)排放因子分布在以煤为主要燃料的区域,高OC、EC、PM_(2.5)排放因子分布在以生物质为主要燃料的区域,并且CO、OC和PM_(2.5)排放因子的区域分布呈现一定的相关性。

农村黑臭水体污染物削减量分配研究

随着城乡经济的不断发展和人民生活水平的提高,农村地区的污染问题日益凸显,其中黑臭水体问题是一大难题。为改善水环境质量,有序开展农村黑臭水体治理工作,以浠水县农村黑臭水体为例,计算浠水县农村黑臭水体污染负荷情况。基于农村黑臭水体的水环境容量,计算各控制单元的削减量,对污染物的削减量进行分层级分配的研究,建立削减量分配模型,确定不同水体的主要污染源及对应的不同污染源的削减量,提高污染治理的效果和可持续性,从而实现精准治污、科学治污。