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 fract...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.展开更多
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 bec...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.展开更多
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 externa...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.展开更多
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 Pollut...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.展开更多
The estimation of non-point source pollution loads into the Danjiangkou Reservoir is highly significant to environmental protection in the watershed. In order to overcome the drawbacks of traditional watershed numeric...The estimation of non-point source pollution loads into the Danjiangkou Reservoir is highly significant to environmental protection in the watershed. In order to overcome the drawbacks of traditional watershed numerical models, a base flow separation method was established coupled with a digital filtering method and a flux method. The digital filtering method has been used to separate the base flows of the Hanjiang,Tianhe, Duhe, Danjiang, Laoguan, and Qihe rivers. Based on daily discharge, base flow, and pollutant concentration data, the flux method was used to calculate the point source pollution load and non-point source pollution load. The results show that:(1) In the year 2013, the total inflow of the six rivers mentioned above accounted for 95.9% of the total inflow to the Danjiangkou Reservoir. The total pollution loads of chemical oxygen demand(CODMn) and total phosphorus(TP) from the six rivers were 58.20 103 t and 1.863 10~3 t, respectively, and the non-point source pollution loads were 39.82 10~3 t and 1.544 10~3 t, respectively, indicating that the non-point source pollution is a major factor(with a contribution rate of 68.4% for CODMnand 82.9% for TP).(2) The Hanjiang River is the most significant contributor of pollution loads to the Danjiangkou Reservoir, and its CODMnand TP contribution rates reached 79.3% and 83.2%, respectively. The Duhe River took the second place.(3) Non-point source pollution mainly occurred in the wet season in 2013, accounting for 80.8% and 90.9% of the total pollution loads of CODMnand TP, respectively. It is concluded that the emphasis of pollution control should be placed on non-point source pollution.展开更多
Agricultural non-point source pollution has become the main part of water pollution prevention and control in China. This paper made a brief introduction to the causes and hazards of agricultural non-point source poll...Agricultural non-point source pollution has become the main part of water pollution prevention and control in China. This paper made a brief introduction to the causes and hazards of agricultural non-point source pollution and the current situation of agricultural non-point source pollution prevention and control in China. In view of the serious agricultural non-point source pollution in water environment of Guangxi and the difference in quality of drinking water between urban and rural areas,it came up with recommendations for strengthening agricultural non-point source pollution prevention and control from scientific distribution,linked operation and maintenance,popular science education,and legal system construction,to guarantee safe and healthy drinking water in rural areas.展开更多
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 discha...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.展开更多
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 co...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.展开更多
The applicability of a non-point source pollution model—SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database, ...The applicability of a non-point source pollution model—SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database, which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage “Brute Force' optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998—1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.展开更多
This study tested and evaluated the agricultural non-point source (AGNPS) model for the Wuchuan catchment, a typical agricultural area in the Jiulong River watershed, Fujian Province, China. The AGNPS model was cali...This study tested and evaluated the agricultural non-point source (AGNPS) model for the Wuchuan catchment, a typical agricultural area in the Jiulong River watershed, Fujian Province, China. The AGNPS model was calibrated and validated for the study area with observed data on ten storms. The data on eight storms in 2002 were used for calibration while data on two storms were used for validation of the model. Considering the lack of water quality data over a long-term series, a novel method, comparing an internal nested catchment with its surrounding catchment, was used to supplement the less long-term series data. Dual calibration and validation of the AGNPS model was obtained by this comparison. The results indicate that the correlation coefficients were 0.99 and 0.98 for runoff, 0.94 and 0.95 for the peak runoff rate of the large catchment and the small catchment, respectively, and 0.76 for the sediment of the small catchment only. Each pair of correlation coefficients is homogeneous for the same event for the two catchments. With the exception of the sediment yield and particulate phosphorus, the peak runoff rate and other nutrients were well predicted. Sensitivity analysis showed that the Soil Conservation Service curve number and rainfall quantity were the most sensitive parameters, which resulted in high output variations. Erosivity and other parameters had little influence on the hydrological and quality outputs.展开更多
[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...[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.展开更多
In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safe...In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...展开更多
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 a...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.展开更多
The land area in a river network is divided into certain-scale square cells for the sake of precision, and, based on the physical mechanisms of rainfall-runoff processes and runoff pollution, the non-point source poll...The land area in a river network is divided into certain-scale square cells for the sake of precision, and, based on the physical mechanisms of rainfall-runoff processes and runoff pollution, the non-point source pollution from cells is estimated using the export coefficients of different land use types. The non-point source pollution from a land cell should all go into the closest fiver reach, so it is distributed according to the terrain of the plain river network area and the positions of land cells and river network reaches. A relationship between a single land cell and its pollution-receiving reach can be determined using this system. In view of the above, a spatial distribution model of the rainfall runoff and non-point source pollution in reaches of a plain river network area was established. This model can provide technological support for further research on the dynamic effects of non-point source pollution on water quality.展开更多
[Objective] The study aimed to discuss the application of a stereo constructed wetland to the treatment of slightly polluted source water. [Method] In this study, a new stereo constructed wetland mode was put forward,...[Objective] The study aimed to discuss the application of a stereo constructed wetland to the treatment of slightly polluted source water. [Method] In this study, a new stereo constructed wetland mode was put forward, and a pilot project of water ecological purification in Xinsheng River, the diversion channel of Shijiuyang Waterwork in Jiaxing City, were analyzed. Afterwards, the impact factors of water purification by the technology were discussed from water quality and quantity, season and climate, species configuration, management and maintenance. [Result] Under three different hydraulic loading conditions, the pilot project effectively improved water SD and DO level, and reduced SS, CODCr, NH3-N, TN and TP significantly in summer and autumn, so that effluent water quality reached surface water standard at Grade III. [Conclusion] The stereo constructed wetland mode composed of constructed wetland and underwater forest used to treat slightly polluted source water is feasible and has a good promotion prospect.展开更多
[Objective] The aim was to study the control countermeasures of agricultural non-point source pollution in lakeside belt of Poyang Lake.[Method] The current situation of water quality of Poyang Lake was analyzed first...[Objective] The aim was to study the control countermeasures of agricultural non-point source pollution in lakeside belt of Poyang Lake.[Method] The current situation of water quality of Poyang Lake was analyzed firstly,then the causes of agricultural non-point source pollution in Duchang section of Poyang Lake were studied,finally corresponding control countermeasures were put forward.[Result] Agricultural non-point source pollution in Duchang section of Poyang Lake was mainly related to the rapid development of pearl industry and livestock industry,aggravated soil erosion and excessive utilization of fertilizer.Based on analysis of current environmental situation and bearing capability of resources in Poyang Lake basin,agricultural non-point source pollution would be controlled through the reduction of external source pollution load,restoration of river wetland and construction of aquatic ecosystem.After the primary implementation of agricultural non-point source pollution control project,the amount of agricultural non-point source pollution in demonstration plot was reduced,and the quality of effluent met the first Class (Class A) of state Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002).Meanwhile,biodiversity index in river wetland increased by about 30%,so the pollution load entering Poyang Lake was decreased.[Conclusion] The study could provide technology integration and demonstration for the environmental remediation in lakeside belt of Poyang Lake.展开更多
The rainfall system was set up on a slope land, which was used with some materials to enhance soil infiltration. The results showed that it was effective to enhance the infiltration of rainwater in soil and reduce the...The rainfall system was set up on a slope land, which was used with some materials to enhance soil infiltration. The results showed that it was effective to enhance the infiltration of rainwater in soil and reduce the pollutants of surface runoff. After the soil meliorated by the lignin polymer and zeolite, runoff was delayed about 10 min and reduced by 44.40%--50.00%, synchronously, the pollutant loads, such as total suspended solids (TSS), chemical oxygen demand by ditromate (CODCr), total nitroger (TN) and total phosphorus (TP), were reduced on averages by 44.58%, 37.80%, 51.62% and 44.11%, respectively. It is an available technique to control the pollution of non-point source from sources.展开更多
Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To ...Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To reveal the relationships between "sourcesink" landscape and NPS pollution based on cell units of a small catchment in the Three Gorges Reservoir Region(TGRR), the runoff and nutrient yields were simulated first by rainfall events on a cell unit scale based on the Annualized AGricultural Non-Point Source Pollution Model(AnnAGNPS). Landscape structure and pattern were quantified with "sourcesink" landscape indicators based on cell units including landscape area indices and locationweighted landscape indices. The results showed that:the study case of small Wangjiagou catchment highlighted a good prediction capability of runoff and nutrient export by the AnnAGNPS model. Throughout the catchment, the spatial distribution trends of four location-weighted landscape indices were similar to the trends of simulated total nitrogen(TN) and total phosphorus(TP), which highlighted the importance of spatial arrangement of "source" and "sink" landscape types in a catchment when estimating pollutant loads. Results by Pearson correlation analysis indicated that the location-weighted landscape index provided a more comprehensive account of multiple factors, and can better reflect NPS-related nutrient loss than other landscape indices applied in single-factor analysis. This study provides new findings for applying the "source-sink" landscape indices based on cell units in small catchments to explain the effect of "source-sink" landscape on nutrient export based on cell unit, and helps improve the understanding of the correlation between "source-sink" landscape and NPS pollution.展开更多
Taihu Lake is located at the center of Changjiang delta region, the Lake and its effluent rivers are important water sources for 40 million around inhabitants and rapidly increasing industrial factories in Shanghai, J...Taihu Lake is located at the center of Changjiang delta region, the Lake and its effluent rivers are important water sources for 40 million around inhabitants and rapidly increasing industrial factories in Shanghai, Ji-angsu and Zhejiang. The pollutants originate mainly from acidy rain, home sewage of the vast number of inhabitants, livestock manure, agricultural fertilizers & pesticides applied over fields in the drainage basin, and the industrial sewage. Due to the kinds of pollutants, the Lake water is getting highly eutrophic, with frequent blooms of blue-green algae. Compared with point-source pollutants, diffuse pollution is much com-plicated and difficult to control. Thus combating non-point pollution (NPP) is paid much great attention. Based on analysis on source-sink of NPP in Taihu Lake basin, it is concluded that the function of forests on NPP control is multiple and important by both source reduction and sink expansion. The primary objective of planting trees through constructing forested wetlands and establishing riparian forest buffers is to control soil & water erosion, decrease agrochemicals application, and improve farming conditions in the region of Taihu Lake basin. Moreover forests help to intercept acidy rain, protect streambanks, uptake nutrients, hold up pollutants and provide habitat for wildlife.展开更多
Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary ...Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary to distinguish their effects.But the non-point source pollution process is interactional as a result of multiple factors,and the collinearity between multiple independent variables limits our ability of reason diagnosis.Thus,taking the Burhatong River Basin,Northeast China as an example,the methods of hydrological simulation,geographic detectors,and redundancy analysis have been combined to determine the impact of natural geographic features and landscape patterns on non-point source pollution in the watershed.The Soil&Water Assessment Tool(SWAT)has been adopted to simulate the spatial and temporal distribution characteristics of total nitrogen and total phosphorus in the watershed.The results show that the proportions of agricultural land and forest area and the location-weighted landscape contrast index(LWLI)are the main indicators influencing the rivers total nitrogen and total phosphorus.The interaction of these indicators with natural geographic features and landscape configuration indicators also significantly influences the changes in total nitrogen(TN)and total phosphorus(TP).Natural geographical features and landscape patterns have different comprehensive effects on non-point source pollution in the dry and wet seasons.TN and TP loads are affected mainly by the change in landscape pattern,especially in the wet season.Although the ecological restoration program has improved forest coverage,the purification effect of increased forest coverage on the water quality in the watershed may be offset by the negative impact of increased forest fragmentation.The high concentration and complexity of farmland patches increase the risk of non-point source pollution spread to a certain extent.展开更多
基金Sponsored by Humanities and Social Sciences Research Project of the Ministry of Education(19YJCZH134)Binzhou University Research Fund(BZXYG1716)Experimental Technology Project Funded by Binzhou University(BZXYSYXM201816)
文摘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.
文摘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.
文摘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.
基金supported by the 11th-Five Year Scientific Support Program of China (No.2006BAD03A13,2006BAD03A07)
文摘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.
基金supported by the National Key Research and Development Program of China(Grants No.2016YFC0402204 and 2016YFC0402207)
文摘The estimation of non-point source pollution loads into the Danjiangkou Reservoir is highly significant to environmental protection in the watershed. In order to overcome the drawbacks of traditional watershed numerical models, a base flow separation method was established coupled with a digital filtering method and a flux method. The digital filtering method has been used to separate the base flows of the Hanjiang,Tianhe, Duhe, Danjiang, Laoguan, and Qihe rivers. Based on daily discharge, base flow, and pollutant concentration data, the flux method was used to calculate the point source pollution load and non-point source pollution load. The results show that:(1) In the year 2013, the total inflow of the six rivers mentioned above accounted for 95.9% of the total inflow to the Danjiangkou Reservoir. The total pollution loads of chemical oxygen demand(CODMn) and total phosphorus(TP) from the six rivers were 58.20 103 t and 1.863 10~3 t, respectively, and the non-point source pollution loads were 39.82 10~3 t and 1.544 10~3 t, respectively, indicating that the non-point source pollution is a major factor(with a contribution rate of 68.4% for CODMnand 82.9% for TP).(2) The Hanjiang River is the most significant contributor of pollution loads to the Danjiangkou Reservoir, and its CODMnand TP contribution rates reached 79.3% and 83.2%, respectively. The Duhe River took the second place.(3) Non-point source pollution mainly occurred in the wet season in 2013, accounting for 80.8% and 90.9% of the total pollution loads of CODMnand TP, respectively. It is concluded that the emphasis of pollution control should be placed on non-point source pollution.
基金Supported by State Key Research and Development Program of Ministry of Science and Technology"Soil Passivation-Physiological Barrier-Enrichment and Removal Technology in Paddy Field with Mild Cadmium Contamination"(2016YED0800705-01)Key Research and Development Program of Guangxi"Research and Demonstration of Remediation Technology in Cadmium and Lead Polluted Paddy Field"(Gui Ke AB16380084)+2 种基金Key Agricultural Science and Technology Project of Guangxi"Integration,Research and Development of Heavy Metal Pollution Prevention Technology for Paddy Field"(201528)Scientific Research and Technological Development Program Project of Nanning City"Research and Demonstration of Integrated Ecological Restoration Technology for Heavy Metal Cadmium Polluted Paddy Field in Nanning"(20162105)Scientific and Technological Service Ability and Party Informationization Construction of Ecological Comprehensive Demonstration Village in Jianning No.1 Team of Xixiangtang District of Nanning(20152054-13)
文摘Agricultural non-point source pollution has become the main part of water pollution prevention and control in China. This paper made a brief introduction to the causes and hazards of agricultural non-point source pollution and the current situation of agricultural non-point source pollution prevention and control in China. In view of the serious agricultural non-point source pollution in water environment of Guangxi and the difference in quality of drinking water between urban and rural areas,it came up with recommendations for strengthening agricultural non-point source pollution prevention and control from scientific distribution,linked operation and maintenance,popular science education,and legal system construction,to guarantee safe and healthy drinking water in rural areas.
基金Sponsored by Significant Scientific and Technological Program of Guizhou Province([2015]2001)
文摘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.
基金supported by Zhejiang A&F University(2022LFR083)Key R&D Program of Zhejiang Province(2021C02038)the International Centre for Bamboo and Rattan(1632021006)。
文摘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.
文摘The applicability of a non-point source pollution model—SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database, which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage “Brute Force' optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998—1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.
文摘This study tested and evaluated the agricultural non-point source (AGNPS) model for the Wuchuan catchment, a typical agricultural area in the Jiulong River watershed, Fujian Province, China. The AGNPS model was calibrated and validated for the study area with observed data on ten storms. The data on eight storms in 2002 were used for calibration while data on two storms were used for validation of the model. Considering the lack of water quality data over a long-term series, a novel method, comparing an internal nested catchment with its surrounding catchment, was used to supplement the less long-term series data. Dual calibration and validation of the AGNPS model was obtained by this comparison. The results indicate that the correlation coefficients were 0.99 and 0.98 for runoff, 0.94 and 0.95 for the peak runoff rate of the large catchment and the small catchment, respectively, and 0.76 for the sediment of the small catchment only. Each pair of correlation coefficients is homogeneous for the same event for the two catchments. With the exception of the sediment yield and particulate phosphorus, the peak runoff rate and other nutrients were well predicted. Sensitivity analysis showed that the Soil Conservation Service curve number and rainfall quantity were the most sensitive parameters, which resulted in high output variations. Erosivity and other parameters had little influence on the hydrological and quality outputs.
基金Supported by Hai River Basin Integrated Water Resources Management Project of Global Environment Facility(SEPA-ZWN-3,C/II/S/09/090)
文摘[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.
文摘In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...
基金Supported by Research on the Comprehensive Control Measures of Agricultural Non-point Source Pollution in the Dianchi Lake Basin Funded by Kunming Agricultural Bureau(2016JC01)Project of Yunnan Engineering Research Center for Urban Characteristic Agriculture(TSNY0201)+7 种基金Scientific Research Foundation of Yunnan Department of Education(2014Y390)Application Base Research Project for Young Scholars of Yunnan Province(2013FD040)Talent Introduction Project of Kunming University(YJL14005)Talent Introduction Foundation of Kunming University(YJL12010)Key Foundation of Kunming University(XJL12020)Scientific Research Project for Undergraduates of Kunming University(XJD16081)Research on the Ecology and Rational Distribution of Main Cultivars in Producing Areas of Raw Materials of China Tobacco in Yunnan ProvinceProject of Construction of the Dominant Key Subject(Ecology)in Universities and Colleges in Yunnan Province(05000511311)
文摘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.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment in China (Grant No. 2008X07101-005)
文摘The land area in a river network is divided into certain-scale square cells for the sake of precision, and, based on the physical mechanisms of rainfall-runoff processes and runoff pollution, the non-point source pollution from cells is estimated using the export coefficients of different land use types. The non-point source pollution from a land cell should all go into the closest fiver reach, so it is distributed according to the terrain of the plain river network area and the positions of land cells and river network reaches. A relationship between a single land cell and its pollution-receiving reach can be determined using this system. In view of the above, a spatial distribution model of the rainfall runoff and non-point source pollution in reaches of a plain river network area was established. This model can provide technological support for further research on the dynamic effects of non-point source pollution on water quality.
基金Supported by National Science and Technology Project of Water Pollution Control and Management(2008ZX07421-001)
文摘[Objective] The study aimed to discuss the application of a stereo constructed wetland to the treatment of slightly polluted source water. [Method] In this study, a new stereo constructed wetland mode was put forward, and a pilot project of water ecological purification in Xinsheng River, the diversion channel of Shijiuyang Waterwork in Jiaxing City, were analyzed. Afterwards, the impact factors of water purification by the technology were discussed from water quality and quantity, season and climate, species configuration, management and maintenance. [Result] Under three different hydraulic loading conditions, the pilot project effectively improved water SD and DO level, and reduced SS, CODCr, NH3-N, TN and TP significantly in summer and autumn, so that effluent water quality reached surface water standard at Grade III. [Conclusion] The stereo constructed wetland mode composed of constructed wetland and underwater forest used to treat slightly polluted source water is feasible and has a good promotion prospect.
基金Supported by Horizontal Subject Project of Jiujiang University(2011019)
文摘[Objective] The aim was to study the control countermeasures of agricultural non-point source pollution in lakeside belt of Poyang Lake.[Method] The current situation of water quality of Poyang Lake was analyzed firstly,then the causes of agricultural non-point source pollution in Duchang section of Poyang Lake were studied,finally corresponding control countermeasures were put forward.[Result] Agricultural non-point source pollution in Duchang section of Poyang Lake was mainly related to the rapid development of pearl industry and livestock industry,aggravated soil erosion and excessive utilization of fertilizer.Based on analysis of current environmental situation and bearing capability of resources in Poyang Lake basin,agricultural non-point source pollution would be controlled through the reduction of external source pollution load,restoration of river wetland and construction of aquatic ecosystem.After the primary implementation of agricultural non-point source pollution control project,the amount of agricultural non-point source pollution in demonstration plot was reduced,and the quality of effluent met the first Class (Class A) of state Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002).Meanwhile,biodiversity index in river wetland increased by about 30%,so the pollution load entering Poyang Lake was decreased.[Conclusion] The study could provide technology integration and demonstration for the environmental remediation in lakeside belt of Poyang Lake.
文摘The rainfall system was set up on a slope land, which was used with some materials to enhance soil infiltration. The results showed that it was effective to enhance the infiltration of rainwater in soil and reduce the pollutants of surface runoff. After the soil meliorated by the lignin polymer and zeolite, runoff was delayed about 10 min and reduced by 44.40%--50.00%, synchronously, the pollutant loads, such as total suspended solids (TSS), chemical oxygen demand by ditromate (CODCr), total nitroger (TN) and total phosphorus (TP), were reduced on averages by 44.58%, 37.80%, 51.62% and 44.11%, respectively. It is an available technique to control the pollution of non-point source from sources.
基金supported by the National Natural Science Foundation of China (Nos. 41671291)
文摘Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To reveal the relationships between "sourcesink" landscape and NPS pollution based on cell units of a small catchment in the Three Gorges Reservoir Region(TGRR), the runoff and nutrient yields were simulated first by rainfall events on a cell unit scale based on the Annualized AGricultural Non-Point Source Pollution Model(AnnAGNPS). Landscape structure and pattern were quantified with "sourcesink" landscape indicators based on cell units including landscape area indices and locationweighted landscape indices. The results showed that:the study case of small Wangjiagou catchment highlighted a good prediction capability of runoff and nutrient export by the AnnAGNPS model. Throughout the catchment, the spatial distribution trends of four location-weighted landscape indices were similar to the trends of simulated total nitrogen(TN) and total phosphorus(TP), which highlighted the importance of spatial arrangement of "source" and "sink" landscape types in a catchment when estimating pollutant loads. Results by Pearson correlation analysis indicated that the location-weighted landscape index provided a more comprehensive account of multiple factors, and can better reflect NPS-related nutrient loss than other landscape indices applied in single-factor analysis. This study provides new findings for applying the "source-sink" landscape indices based on cell units in small catchments to explain the effect of "source-sink" landscape on nutrient export based on cell unit, and helps improve the understanding of the correlation between "source-sink" landscape and NPS pollution.
文摘Taihu Lake is located at the center of Changjiang delta region, the Lake and its effluent rivers are important water sources for 40 million around inhabitants and rapidly increasing industrial factories in Shanghai, Ji-angsu and Zhejiang. The pollutants originate mainly from acidy rain, home sewage of the vast number of inhabitants, livestock manure, agricultural fertilizers & pesticides applied over fields in the drainage basin, and the industrial sewage. Due to the kinds of pollutants, the Lake water is getting highly eutrophic, with frequent blooms of blue-green algae. Compared with point-source pollutants, diffuse pollution is much com-plicated and difficult to control. Thus combating non-point pollution (NPP) is paid much great attention. Based on analysis on source-sink of NPP in Taihu Lake basin, it is concluded that the function of forests on NPP control is multiple and important by both source reduction and sink expansion. The primary objective of planting trees through constructing forested wetlands and establishing riparian forest buffers is to control soil & water erosion, decrease agrochemicals application, and improve farming conditions in the region of Taihu Lake basin. Moreover forests help to intercept acidy rain, protect streambanks, uptake nutrients, hold up pollutants and provide habitat for wildlife.
基金Under the auspices of the National Key R&D Program(No.2019YFC0409104)the National Natural Science Foundation of China(No.41830643)the National Science and Technology Basic Resources Survey Project(No.2019FY101703)。
文摘Changes in natural geographic features and landscape patterns directly influence the hydrology and non-point source pollution processes in the watershed;however,to slow down non-point source pollution,it is necessary to distinguish their effects.But the non-point source pollution process is interactional as a result of multiple factors,and the collinearity between multiple independent variables limits our ability of reason diagnosis.Thus,taking the Burhatong River Basin,Northeast China as an example,the methods of hydrological simulation,geographic detectors,and redundancy analysis have been combined to determine the impact of natural geographic features and landscape patterns on non-point source pollution in the watershed.The Soil&Water Assessment Tool(SWAT)has been adopted to simulate the spatial and temporal distribution characteristics of total nitrogen and total phosphorus in the watershed.The results show that the proportions of agricultural land and forest area and the location-weighted landscape contrast index(LWLI)are the main indicators influencing the rivers total nitrogen and total phosphorus.The interaction of these indicators with natural geographic features and landscape configuration indicators also significantly influences the changes in total nitrogen(TN)and total phosphorus(TP).Natural geographical features and landscape patterns have different comprehensive effects on non-point source pollution in the dry and wet seasons.TN and TP loads are affected mainly by the change in landscape pattern,especially in the wet season.Although the ecological restoration program has improved forest coverage,the purification effect of increased forest coverage on the water quality in the watershed may be offset by the negative impact of increased forest fragmentation.The high concentration and complexity of farmland patches increase the risk of non-point source pollution spread to a certain extent.