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1.
采用DPeRS模型对淮河流域氮、磷面源污染空间特征进行遥感像元尺度解析,并对"十三五"《重点流域水污染防治规划》中划定的淮河流域235个控制单元进行面源污染优先控制单元分析。结果表明,淮河流域2016年TN和TP面源污染排放量分别为44. 99和2. 44万t,入河量分别为27. 72和1. 27万t;空间分布上,淮河流域的东部和南部氮、磷污染程度较为显著,北部污染程度较轻;农田径流型是淮河流域最主要的氮、磷面源污染源,均占到总污染量90%以上,是该流域氮、磷面源污染防治优先控制的污染源,对于TN指标次要影响类型为城镇地表径流,对于TP指标次要影响类型为畜禽养殖;筛选出淮河流域TN和TP面源污染优先控制单元分别为164和185个,面积占比分别为75. 3%和85. 0%。  相似文献   

2.
第二松花江面源污染时空分布规律的研究   总被引:1,自引:0,他引:1  
第二松花江流域作为松花江干流的主要产水区,其污染年负荷关乎下游水质的安全。面源污染是第二松花江的重要污染来源,采用输出系数法估算面源污染年负荷量,通过流域土地利用类型、社会经济信息等因素,利用有资料年的统计数据,进行面源污染年负荷量在时间、空间上的展布,探寻第二松花江流域面源污染年负荷量的空间分布规律,为水环境管理部门提供理论依据。  相似文献   

3.
为精准治理流域非点源氮磷污染,基于SWAT模型,运用本地区第二次全国污染源普查数据和2000—2019年流域水文、水质数据,开展湘江永州流域非点源氮磷污染模拟。结果表明:湘江永州流域建立的SWAT模型具有较好的模拟效果,流域2005—2019年的总氮月均污染负荷为383.40~17 998.70 t/m;总磷月均污染负荷为64.62~567.86 t/m,总氮和总磷各月污染负荷均与各月降雨量呈显著相关关系;农田和林地是本流域总氮、总磷污染负荷总量最大的2种用地类型,但两者之间单位面积输出的污染负荷强度却相反,林地对流域水污染防控具有正面效应,农田种植面源污染是非点源氮磷污染治理的重点。  相似文献   

4.
以南京市上秦淮片区二横沟小流域为例,在污染源调查的基础上,采用分类法,利用改进后的污染输出系数模型进行流域污染负荷核算,得到外源污染物入河负荷量及各污染源的贡献率。研究结果表明,上秦淮片区二横沟流域内污染物排放负荷总量为COD 229.9 t/a、TN 25.8 t/a、NH3-N 22.4 t/a、TP 1.7 t/a,入河负荷量为COD 47.1 t/a、TN 5.5 t/a、NH3-N 4.6 t/a、TP 0.36 t/a,主要来自面源污染,点源污染较小。其中,生活面源污染年入河贡献率最高,为44.5%,林地面源污染贡献率最低,为0.1%,水产面源、道路面源、水田面源和旱地面源贡献率分别为31.6%、16.2%、6.2%和1.4%。  相似文献   

5.
根据2021年5月—2022年4月合溪新港河流水量、水质(TN和TP)的同步监测数据,利用通量模型核算了合溪新港污染物(TN和TP)通量。通过测算合溪新港TN、TP通量与断面降雨强度、水质的响应关系,分析了该区域的污染类型及特点,为后期水质污染调查及通量研究提供了新思路。结果表明:合溪新港流量与降雨量存在明显相关关系,在强降雨期(7—8月)水体流量最高,占监测周期总流量的57.77%;少雨期则流量最低,且会出现湖水倒灌现象(11—12月)。通过分析合溪新港TN、TP通量与流量、水质的相关关系,确定了该流域污染类型为点源污染及农业面源污染共存的混合型污染,且在高强度降雨时污染物负荷量较大。综上,可针对农业面源污染对该流域治理提出相关对策,建立农业面源污染防治体系,以有效降低TN和TP污染物的入湖通量,减少太湖TN和TP污染物负荷量。  相似文献   

6.
使用问卷调查法对舒城县丰乐河小流域农业面源污染现状进行实地调研,采用等标污染负荷法对流域区域内千人桥镇和桃溪镇的农业种植污染、畜禽养殖污染与农村生活污染进行综合分析。研究表明,在舒城县丰乐河小流域两个乡镇的农业面源污染排放源中,种植业TN、TP的排放量为4578 t,污染负荷率为2075%;畜禽养殖业COD、TN、TP的排放量为2659 t,污染负荷率为1205%;农村生活源COD、TN、TP的排放量为14828 t,污染负荷率为6720%。在选择的3个评价因子中,COD的污染负荷率最高(6947%),其次为TN(2822%),TP最低(231%)。农村生活污染是该小流域农业面源污染物的主要来源,也是农业面源污染控制的重点。  相似文献   

7.
采用遥感分布式面源污染评估模型(DPeRS),对2018年黄河流域(甘肃段)面源污染空间分布特征进行分析,具体包括多类型污染量产排特征解析和流域优先管控单元识别。结果表明,污染量上,2018年黄河流域(甘肃段)总氮(TN)、总磷(TP)、氨氮(NH3-N)、化学需氧量(CODCr)的面源污染排放负荷分别为65.6,11.8,19.1和77.2 kg/km2,入河量分别为836.7,33.3,220.2和1 353.3 t;空间分布上,氮型(TN和NH3-N)排放负荷高值区主要分布在流域中部和东部局部地区,流域大部分地区TP排放负荷均较高,CODCr面源污染排放负荷高值区分布较为零散。与排放负荷相比,黄河流域(甘肃段)面源污染入河负荷并不突出,这与该地区水资源量少有密切关系。筛选出黄河流域(甘肃段)面源污染优先控制单元15个,面积占比为85.2%,I类优控单元主要分布在庆阳市、天水市、兰州市和白银市等地区,II类优控单元主要分布在甘南藏族自治州,且TN、TP、NH3-N和CODCr面源污染优控单元识别结果的平均精度达到80%。  相似文献   

8.
农业面源污染防治的监测问题分析   总被引:1,自引:0,他引:1       下载免费PDF全文
近年来,农业面源污染已成为许多国家和地区水环境质量改善的主要影响因素,开展农业面源污染监测将为深入打好污染防治攻坚战提供重要支撑。该文系统分析当前我国农业面源污染监测存在的主要问题,综合考虑国内外经验,提出如下建议:采取空间嵌套式的布局模式优化地表水环境监测点位,充分发挥环境监测的预测预报和风险评估功能;建立包括污染源、产排污系数和空间传输过程的农业面源污染全过程监测网络;定期开展土壤氮、磷养分含量评估和地下水硝酸盐氮测定和评估;建立完善数据整合与共享机制。  相似文献   

9.
将农业面源污染风险区划入生态保护红线中,防范由此导致的饮用水水源富营养化现象,是值得深入探讨的科学问题。以南水北调中线重要水源地丹江口水库流域十堰段为例,基于农业面源污染风险区的识别,通过情景分析探讨生态保护红线优化方法,改善区域生态环境,推动绿色发展。结果表明:将农业面源污染极高风险区划入生态保护红线,区域氮、磷流失削减率可分别达35.9%和26.33%,在一定程度上增强了生态系统连通性,且人口生态压力指数较小(0.23),可统筹生态效益和经济效益的发展。研究结果有望为存在农业面源污染风险的丘陵山区提供一种红线优化新思路。  相似文献   

10.
兴山香溪河流域农业面源污染问题及防治对策研究   总被引:2,自引:0,他引:2  
通过对1955-2007年湖北宜昌兴山香溪河流域农业面源污染问题相关统计资料的分析,结果表明:引起湖北兴山香溪河流域水环境恶化的农业面源污染因子,主要包括化肥、农药、畜禽养殖、生活污水等;并提出了香溪河农业面源污染的防治对策,主要有:完善农业立法、强化经营管理措施,积极推广高产高效生态耕作技术,加强农药化肥物质投入最小化技术,开展畜禽粪便多用途综合利用,加强农村生活污水处理的研究.  相似文献   

11.
微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬   总被引:24,自引:5,他引:24       下载免费PDF全文
用微波消解-原子吸收光度法测定土壤中铜,锌,铅,镉,镍和铬。通过硝酸-氢氟酸-过氧化氢体系消解液对土壤样品消解,选择出微波最佳消解条件。对硝酸-盐酸-过氧化氢体系消解液和硝酸-氢氟酸-过氧化氢体系消解液进行消解对比试验,发现前者不能将土壤样品完全消解,后者能将样品消解完全,但需将消解液中剩余的酸赶尽,否则测定结果将明显偏低。微波消解土壤与传统电热消解相比,操作简便快速,可提高工作效率。  相似文献   

12.
An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns. As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment. To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties. This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making, expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian) approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally, we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated, practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the readers to future research.   相似文献   

13.
Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.  相似文献   

14.
The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> -1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.  相似文献   

15.
This paper gives mathematical details and sample applications of SWAGMAN Farm (SWAGMAN, Salt Water and Groundwater Management), a farm-scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. The model is capable of determining optimum mix of land use to keep watertable and soil salinity within acceptable limits while maximising the economic returns. Alternatively, the model can simulate water and salt balance and economics of a given cropping preference. Web-based and Geographic Information Systems versions of the model are available for integration with the environmental reporting systems of the irrigation areas.  相似文献   

16.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   

17.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   

18.
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.  相似文献   

19.
The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.  相似文献   

20.
Assessments of long-term relationships between changes innutrient inputs and wetland nutrient concentrations can becomplicated by fluctuations in other environmental factors aswell as by problems typical of long-term monitoring data.Consequently, statistical analysisof these types of data sets requirescareful consideration of environmental covariates, potentialbiases in the monitoring design, and irregularities caused bychanges in field sampling protocols. We evaluated therelationship between anthropogenic phosphorus (P) inputs andwater-column total P (TP) concentrations in a northernEverglades marsh by statistically analyzing available datacollected from several sampling programs over the past 20 years(1978–1997). Canal inputs of agricultural runoff contributemost of the P to the marsh and have produced a zone ofenrichment within the marsh during the past few decades.Regression analyses showed that both canal and marsh TPconcentrations increased during the 1980s and then decreased inthe 1990s. However, the statistical relationship between canal Pinputs and marsh TP, while significant, generally was weakexcept for marsh locations adjacent to the canal. Strongerrelationships existed between marsh TP and hydrologic parameterssuch as marsh water depth, which is controlled by changes inweather patterns and marsh management. In particular, dryconditions during the 1980s may have contributed to observedincreases in marsh P concentrations and the movement of a P`front' further into the marsh. Higher rainfall and water depthsand agricultural best management programs initiated during the1990s have been associated with reduced P concentrations incanal waters entering the marsh. While it is anticipated thatthis reduction eventually will result in lower marsh TPconcentrations, this effect is not yet evident, possibly due tointernal loading of P from enriched marsh soils. Our findingsillustrate some of the environmental factors that can complicateattempts to develop empirical relationships between P inputs andwetland P concentrations and to use such relationships to forecast changesin marsh concentrations based on past monitoring data alone.  相似文献   

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