Ecological Remediation Measures for Non-point Source Pollution Based on Source-Sink Landscape Theory: A Case Study of Huanghou Basin

The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has become a focal point and challenge in water pollution treatment research.The study area for this research was the Huanghou basin in Guizhou Province,southwest China.The land use type of the basin was analyzed using remote sensing technology,and water quality data was collected by distributing points throughout the basin,based on source-sink landscape theory.The distribution map of the basin’s source-sink landscape and the results of water quality data accurately and efficiently identified the areas with high risk of non-point source pollution in the western and southwestern residential and agricultural areas of the upper basin.Hence,a strategy of“increasing sinks and decreasing sources”was proposed.The strategy was implemented at both macro and micro levels to address non-point source pollution in the basin using ecological remediation techniques.The work to control karst rocky desertification should continue at a macro level.The rocky desertification area in the basin should gradually transform into grassland and forested land,while increasing the overall area of the sink landscape.Ecological restoration techniques,such as slope planting,riparian zone vegetation restoration,increasing plant abundance,and restoring aquatic plants,can effectively control non-point source pollution at the micro level.Compared to traditional control methods,this remediation strategy focuses on source and process control.It is more effective and does not require large-scale water pollution control projects,which can save a lot of environmental control funds and management costs.Therefore,it has greater research significance and application value.

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.

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.

Controlling Non-Point Source Pollution in Australian Agricultural Systems

The Australian farming sector is continuing to intensify, particularly within 300 km of the east and southern coastlines. In the future there will be fewer and larger farms, which will use more fertilizer, support more stock, grow more monoculture crops, and utilise more marginal soils. This is likely to increase the major environmental impacts of soil degradation, salt, nutrient and sediment contamination of waterways, and greenhouse gas emissions. Australian national water policy continues to focus on land, stream and groundwater salinity issues, although there is now a greater recognition of the importance of nitrogen and phosphorus losses from agriculture. The general philosophy of policy for dealing with non- point source pollution has been towards a voluntary rather than regulatory approach, with state and national governments supporting a range of programs to encourage sustainable agricultural practices. A catchment (watershed) based approach, through the use of integrated catchment management plans, is the primary way that non-point source pollution is addressed at the farm and local level. At an industry level, cotton, grains, meat, sugarcane and dairy amongst others, as well as the Australian fertilizer industry, have responded to non-point source issues by investing in research and development, and developing codes of practice aimed at abating these environmental impacts. Understanding the economic, social, political and cultural contexts of farming as well as the environmental impacts of agriculture are very important in determining the appropriateness of policy responses for Australian farming systems.

New Normal Control of Agricultural Non-point Source Pollution in the Dianchi Lake Basin

Based on Kunming statistical yearbook and field survey data of agricultural non-point source pollution in counties or districts in the Dianchi Lake basin,previous and current situation of agricultural production and agricultural non-point source pollution control in the Dianchi Lake basin were studied,and countermeasures and suggestions of comprehensive control of agricultural non-point source pollution in the basin were proposed.

The Roles of Countrywomen in Controlling Non-point Source Pollution

The main causes of non-point source pollution in Taihu Lake are the improper ways of crop production, animal husbandry, and daily runoff. The paper discusses the relationship between countrywomen and non-point source pollution control by 731 questionnaires in Weidu village and 466 questionnaires in Dapu Town. The roles of countrywomen have changed in families and they have close relationship with non-point source pollution. Furthermore, we discuss the possibility and methods of organizing countrywomen in non-point source pollution control.

Current Situation and Control Measures of Agricultural Non-point Source Pollution in Typical Basin of South China

In view of the serious non-point source pollution of agriculture in the areas where crop production is concentrated in southern China,the present situation of agricultural non-point source pollution in southern watershed and the main technical measures adopted in the practice of comprehensive prevention and control in recent years are analyzed from the perspectives of different pollution sources such as planting,livestock and poultry breeding,aquaculture and village area runoff.From the perspective of functional restoration and optimization of farmland ecosystem,the countermeasures are put forward,such as strengthening the control of high qualityoriented pollution reduction,layout optimization,constructing circulation system and improving management system,constructing comprehensive prevention and control strategies for ecosystem elements and material exchange,energy flow and logistics linkage,information flow exchange,and maintaining and improving the ability of agricultural ecosystem itself to absorb non-point source pollution.

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.

Analysis on the Status of Agricultural Non-point Source Pollution in Xinan River Basin

Taking Xinan River basin as research object,the status of agricultural non-point source pollution was analyzed based on field survey,as well as the effect of fertilizer and pesticide leaching and runoff,livestock and poultry breeding and rural domestic pollution on non-point source TN and TP.At last,some technical countermeasures of controlling non-point source pollution were put forward according to the characteristics of agricultural non-point source pollution in Xinan River basin.

Advances in History, Current Situation and Control of Agricultural Non-point Source Pollution in the Dianchi Lake Basin

Based on Kunming statistical yearbook and field survey data of agricultural non-point source pollution in counties or districts in the Dianchi Lake basin,advances in the history,current situation and control measures of agricultural non-point source pollution in the basin were summarized to provide theoretical and technical support for the thorough improvement of present situation of water pollution in the basin.

Prevention and Control of Rural Environmental Pollution Based on Rural Revitalization Strategy

In 2018,the rural revitalization strategy proposed by the No. 1 Document of the central government. Based on the current situation of rural environmental pollution in China,this paper explored the relationship between rural revitalization strategy and prevention and control of rural environmental pollution. On this basis,it analyzed the causes of serious rural environmental pollution in China,Finally,it came up with recommendations including establishing a sound rural environmental governance system,making diversified capital investment for nurturing " green farmers".

Agricultural Non-point Source Pollution in Drinking Water Conservation Area of the Hongfeng Lake in Guiyang City

On the basis of investigating rural population, land types, livestock and poultry breeding scale in drinking water conservation area of the Hongfeng Lake in Guiyang City, as well as the urban domestic pol utant discharge coefficient, livestock and poultry excretion coefficient, nitrogen fertilizer and phosphate fertilizer loss rate in the first national pollution source survey, this paper tried to explore current situation of agricultural non-point source pollution, and provide scientific support for the pollution control. The results showed that in the drinking water conservation area of the Hongfeng lake in 2013, contribution rate of pollution sources to the water pollution in the Hongfeng Lake followed the sequence "livestock and poultry breeding > rural life > farmland fertilizer". Among all agricultural non-point source pollutants, livestock and poultry breeding pollutants were major pollution sources, with a contribution rate to CODCr, TP and NH3-N in water above 50%; rural domestic pollutants were also important pollution sources, its contribution rate to CODCr and NH3-N was 43.49% and 46.69%, respectively; contribution rate of farmland fertilizer pollutants to TN and TP was 33.76% and 27.71%, respectively, higher than that of rural domestic pollutants(25.87% and 6.75%). Therefore, the control of non-point source pollution within the drinking water conservation area should be enhanced, so as to control the pollution from the source.

Removal of Agricultural Non-Point Source Pollutants by Artificial Aquatic Food Web System: A Study Case of the Control of Cynobacterial Bloom in Jiyu River

An artificial aquatic food web (AAFW) system was designed to remove the non-point source pollutants in eutrophic Jiyu river. A certain amount of Scenedesmus obliquus and Daphnia pulex was cultured in the system for the control of serious cyanobacterial bloom. The AAFW system was a continuous-flow system including one storage basin of 3 m3 capacity with polluted river water (the total nitrogen-TN: 4.49 mg⋅l-1;the total phosphorus-TP: 0.192 mg⋅l-1), one phytoplankton tank of 3 m3 capacity with an initial concentrations of S. obliquus about 5.8 × 103 ind⋅l-1, and one zooplankton growth chamber of 1.5 m3 capacity with an initial abundance of D. pulex about 22.5 ind⋅l-1. The system was optimized by setting hydraulic retention time of phytoplankton tank as 5 days and the experiments were operated for 45 days. Compared with the polluted river, TN and TP were removed about 28% and 47% by the AAFW system, respectively. The biomass of phytoplankton decrease from 6.33 mg⋅l-1 to 1.48 mg⋅l-1 and the percentage of cyanobacteria decrease from 43.93% to 2.36%, the biomass of Crustacean zooplankton increase from 0.34 mg⋅l-1 to 1.53 mg⋅l-1 and the percentage of D. pulex increase from 19.19% to 57.62%. Our results indicated that the AAFW system not only is an efficient, flexible system for reducing nutrient levels in tributary rivers, but also has an ability to control the cyanobacteria bloom and rebuilding the aquatic ecosystem from the polluted river water.

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.

The Occurrence and Prevention of Filamentous Algae in Ecological Purification System of Micro-polluted Water

[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized and analyzed. Considering the ecological purification in north- ern Jiangsu, the occurrence and prevention of filamentous algae in water, the method to prevent filamentous algae in polluted water was discussed. [ Result] The results showed that by measures of improving planting density, regular harvesting, and water flow state control before the filamentous algae blooming period, together with improving local pH value, light interference and ecological control during the blooming period, can effectively control the filamentous algae blooming. [ Condusion] The study of the happening mechanism of filamentous algae provided theoretical references and the technical basis in the work of filamentous algae prevention and control.

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.

Approach to estimating non-point pollutant load removal rates based on water environmental capacity: a case study in Shenzhen

An innovative approach based on water environmental capacity for non-point source NPS pollution removal rate estimation was discussed by using both univariate and multivariate data analysis.Taking Shenzhen city as the study case a 67% to 74% NPS pollutant load removal rate can lead to meeting the chemical oxygen demand COD pollution control target for most watersheds.In contrast it is hardly to achieve the ammonia nitrogen NH4-N total phosphorus TP and biological oxygen demand BOD5 pollution control target by simply removing NPS pollutants. This highlights that the pollution control strategies should be taken according to different pollutant species and sources in different watersheds rather than one-size-fits-all .

Control division of agricultural non-point source pollution at medium-sized watershed scale in Southeast China

This paper presents the study carried out for controlling agricultural non-point source pollution(NSP)in a medium-sized watershed covering 1.47×10^(4) km^(2) in Southeast China using quantitative analysis coupled with geographic information system(GIS),universal soil loss equation(USLE),soil conservation service-curve number(SCS-CN),nutrient loss equations,and annualized agricultural nonpoint source model(AnnAGNPS).Based on the quantitative results derived from GIS and environmental models,five control division units were generated for NSP control in Jiulong River watershed,namely,controlling unit for soil losses,controlling unit for livestock breeding and soil losses,controlling unit for excessive fertilizer use and livestock breeding,controlling unit for soil losses and fertilizer use,and controlling unit for excessive fertilizer use and soil losses.This study proved that integrating GIS with environmental models can be adopted to efficiently evaluate major sources and contributors of NSP,and identify the critical source areas of NSP,which enables adjusting measures to local conditions by further control division units developed through such study for control and management of water quality degradation induced by NSP in the Jiulong River watershed.

河套灌区农业高效节水与面源污染防控技术

针对河套灌区水资源短缺、农业面源污染严重等问题,从不同空间尺度和治理环节入手开展灌区农业高效节水与面源污染源头防控技术研究。研发了针对污染源头的农田水肥盐药调控管理技术模式(包括除草剂残留研究与用量推荐、土壤水氮盐和作物生长对水肥管理的响应、减量膜上秋浇技术及次生盐渍化土壤微生物改良技术)、针对农田排水的富氧生态沟渠截污净化技术模式和区域尺度的面源污染空间解析识别技术,并集成构建了贯穿源头控污—过程削污—区域查污—系统调污的高效节水型农业面源污染防控技术体系。基于现状研究和新发展理念提出了河套灌区水土资源领域研究的几点认识,相关成果为河套灌区高质量发展提供了重要支撑,对同类型灌区具有重要借鉴意义。