The Niagara River: A water quality management overview

The Niagara River constitutes part of the Laurentian Great Lakes and St. Lawrence River system which represents approximately 80% of North America's supply of surface fresh water. The river is a major source of water for industry, municipalities, recreation and power generation and is the link between Lakes Erie and Ontario. The river forms part of the Canada-U.S. border and falls under the jurisdiction of both countries.The massive industrialization of the region surrounding the river has led to a typical resource use conflict situation in which pollution of the river continues to be a major public concern.A number of constitutional, institutional and jurisdictional factors make the management of the Niagara River an involved and complicated matter. The interests, intent, philosophies, laws and regulations are not necessarily the same among the numerous jurisdiction involved. Despite these differences, however, Canada and the United States have succeeded in developing and implementing a model cooperative international management plan for the river. An overview of the main international aspects relating to the development and implementation of this plan, the Niagara River Toxics Management Plan, is presented.     

Inferences about point source loadings from upstream/downstream river monitoring data

Areas of Concern such as the Niagara and Detroit Rivers contain a myriad of point and non-point sources. These are difficult and expensive to monitor and often present unique analytical problems and so are subject to analytical error. The Niagara River Toxics Committee (NRTC) and the Upper Great Lakes Connecting Channels Study Modeling Committee designed programs to indirectly monitor these sources by upstream/downstream sampling at the head and mouth of the rivers. These two studies are compared and the data analysis problems that were encountered are discussed. Upstream/downstream samples were paired to obtain differential loadings wherever possible, but when some results were reported as below the detection limit, a maximum likelihood estimate was used. The resulting differential loading, adjusted for non-point sources, is the total point source load to the river minus any losses due to volatilization, settling or degradation.     

高纬区阿什河面源氮和磷污染输出特征

基于阿什河2008—2010年水质监测和流量监测结果,利用改进的埃特金和相关性拟合插值法,补全监测条件限制造成的缺失数据,再利用基流分割法,估算阿什河面源氮和磷污染输出量,分析其污染特征。结果显示:阿什河进入松花江的污染负荷峰值一般出现在3—5月或者7—9月,主要由春汛或夏汛造成,峰值出现时污染来源以面源污染为主。2008—2010年阿什河面源污染输出量表现出TP减少,TN和NH_4~+-N增加的趋势。阿什河年均输出量TN约为5 436.6 t,NH_4~+-N约为3 057.8 t,TP约为554.8 t,其中,点源污染为2 775.8、1 440.7、250.8 t,面源污染为2 660.7、1 630.7、304.1 t,面源污染占总量的50%左右。     

Status of the Niagara River point source discharge information: Sampling design and estimation of loading

Two basic requirements, low bias and high precision, are necessary for generating reliable estimates for the load from point and nonpoint sources of pollution. Biases and low precision can be the result of using a bad sampling design and/or inadequate method of estimation. The effects of biases can be reduced at the design stage prior to the data collection or at the data anlysis stage. This paper discusses the statistical issues involved in generating adequate load estimations using recently published point source discharge data from the Niagara River to illustrate these issues.     

Phosphorus Load Reduction Goals for Feitsui Reservoir Watershed, Taiwan

The present paper describes an effort for developing the total maximum daily load (TMDL) for phosphorus and a load reduction strategy for the Feitsui Reservoir in Northern Taiwan. BASINS model was employed to estimate watershed pollutant loads from nonpoint sources (NPS) in the Feitsui Reservoir watershed. The BASINS model was calibrated using field data collected during a 2-year sampling period and then used to compute watershed pollutant loadings into the Feitsui Reservoir. The simulated results indicate that the average annual total phosphorus (TP) loading into the reservoir is 18,910 kg/year, which consists of non-point source loading of 16,003 kg/year, and point source loading of 2,907 kg/year. The Vollenweider mass balance model was used next to determine the degree of eutrophication under current pollutant loading and the load reduction needed to keep the reservoir from being eutrophic. It was estimated that Feitsui Reservoir can becoming of the oligotrophic state if the average annual TP loading is reduced by 37% or more. The results provide the basis on which an integrated control action plan for both point and nonpoint sources of pollution in the watershed can be developed.     

Nonpoint Source Pollution Assessment of Wujiang RiverWatershed in Guizhou Province,SW China

The amount of pollution from nonpoint sources flowing in the streams of the Wujiang River watershed in Guizhou Province, SW China, is estimated by a geographic information system (GIS)-based method using rainfall, surface runoff and land use data. A grid of cells of 100 m in size is laid over the landscape. For each cell, mean annual surface runoff is estimated from rainfall and percent land use, and expected pollutant concentration is estimated from land use. The product of surface runoff and concentration gives expected pollutant loading from that cell. These loadings are accumulated going downstream to give the expected annual pollutant loadings in streams and rivers. By dividing these accumulated loadings by the similarly accumulated mean annual surface runoff, the expected pollutant concentration from nonpoint sources is determined for each location in a stream or river. Observed pollutant concentrations in the watershed are averaged at each sample point and compared to the expected concentrations at the same locations determined from the grid cell model. In general, annual nonpoint source nutrient loadings in the Wujiang River watershed are seen to be predominantly from the agricultural and meadow areas. The total annual loadings through the outlet of the watershed are 40,309 and 2,607 tons for total nitrogen (TN) and total phosphorus (TP), respectively.     

“引江济太”对太湖北部底质及水质总磷的影响

应用GIS技术研究了"引江济太"对太湖北部底质与水质总磷(TP)浓度的影响。研究结果表明,2014—2019年,调水北部沿线4个点位底质TP浓度降幅为59.8%～80.5%;不同点位的水质TP浓度变化存在差异,入湖口点位下降14.1%,沿线其他点位分别上升37.4%、38.6%和45.0%。从空间分布来看,太湖水质TP始终呈明显的"西高东低"分布特点,但底质TP的分布未显示出该类规律。望亭水利枢纽调水情况与入湖口5#点位底质TP浓度呈一定程度的正相关,在调水入湖水量大于出湖水量的年份,5#点位底质TP浓度会偏高。"引江济太"会对太湖北部调水沿线,特别是入湖口附近水域的TP含量产生较大影响,并通过水流迁移与底质再悬浮释放影响下游水域。如何降低望虞河及周边支流的入湖泥沙量将是今后开展科学调水、保障贡湖水源地水质安全的重点研究方向之一。     

Use of Scale Invariance in Evaluating Judgement Indicators

Indicators are used to draw conclusions about ecological endpoints when these endpoints cannot be measured directly. In many cases, inferences about an endpoint are only possible because assumptions have been made about the relationship between indicator and endpoint; we refer to such indicators as judgement indicators. The validity of inferences made using a judgement indicator can be gauged by examining the known or assumed form of the general relationship between indicator and endpoint. The rules for this kind of inference are a consequence of scale invariance, which originates from measurement theory. For simple indicators comprised of a single indicator measurement, the inferences allowed – equivalence, rank, equality of intervals, and equality of ratios – depend on whether the data are nominal, ordinal, interval, or ratio scaled. For composite indicators containing two or more simple indicators, inferences are also affected by the mathematical form of combination; e.g., whether the terms are summed or multiplied. Standardizing simple or composite indicators can allow inferences about the relative importance of observations, based on the natural range of occurrence. Scale invariance is a particularly important consideration in landscape assessments, since these often make use of judgement indicators.     

Trend evaluation of water quality parameters in the Niagara and St. Lawrence Rivers

Physical and chemical (nutrients and major ions) indicators of water quality monitored by Environment Canada between 1977 and 1987 in the Niagara River at Niagara-on-the-Lake and in the St. Lawrence River at Wolfe Island are analyzed for seasonal and annual variations. Parametric methods such as moving averages and linear regression and nonparametric methods (Spearman's rank coefficient) are used to test for the existence of trends in these data. The results indicate that specific conductivity, sodium and chloride have decreased significantly over the period of study. During the same period there is no significant trend for either discharge and nutrients.     

An estimation on budget and control of phosphorus in the Changjiang River catchment

Based on field investigations in the Changjiang River mouth, rain sampling from the river's upper reaches to the mouth, historical data, and relevant literatures, the budget and major control factors of total phosphorus (TP) and dissolved inorganic phosphorus (DIP) in the river catchment were estimated and discussed from the catchment scale. It will supply a base for effective controlling P concentration in the Changjiang River and its mouth. Results show that the export fluxes of TP and DIP were mainly controlled by the river runoff. The TP and DIP in the Changjiang River came mainly from agricultural nonpoint source P losses from fertilizer and soil and point sources of industrial waste and residential sewage discharges. The export fluxes of TP and DIP in the river mouth were only 27.0% and 28.3% of the imports from the river catchment, respectively, suggesting that most of P were removed in transportation. A mass of freshwater marshes in the river catchment were the main areas to remove P. Significant increasing in utilization of fertilizer P and incessant increasing in water and soil loss areas were the primary reasons of agricultural nonpoint source P losses. How to decrease the agricultural nonpoint source P loss from the catchment scale is a key controlling P concentration in the Changjiang River and its mouth. The point source industrial waste P discharge has been primarily treated in the river catchment, but the residential sewage P discharge needs further control.     

基于比值法解析老城区河段氮磷污染特征

2013年12月—2015年2月,对南淝河老城区约4 km河段水体和主要点源的氮、磷污染物进行测定,并利用碳氮比(CODCr/TN)、氮磷比(TN/TP)、氨氮百分含量(NH3-N/TN)等主要指标对所得数据进行分析研究。结果表明,南淝河老城区段水体的氮磷污染严重,氨氮百分含量接近甚至超过50%,具有一般城市生活污水的特征;氮磷比在春夏季处于藻类适宜的生长范围(9.0TN/TP22.6);整个水体处于低碳氮比水平(碳氮比小于2.5),不利于水体的净化;主要受上游望塘污水处理厂、城市生活污水和地表径流的影响。其主要支流四里河水体的氮磷污染亦相当严重,且氮、磷污染物的输入途径一致。     

萍水河水质监测点的优化

城市内河流水质监测点位的优化,是全面掌握河流水质状况的关键。文章采用贴近度法对萍乡市萍水河2005—2015年水质及监测点位变化进行分析评价,并提出优化建议。根据萍水河水质污染特征,选择化学需氧量、五日生化需氧量、氨氮、总磷、总氮和高锰酸钾盐指数作为评价指标,结果表明:2005—2015年,萍水河水环境质量整体情况较好,但在2010年后呈下降趋势;监测点布设方案的调整有一定合理性,也有欠妥之处;对目前监测点位进行删减,得到了水质优化监测布点方案。     

2016—2019年长江经济带总磷污染及治理特征分析

基于环境统计数据分析了长江经济带工业源和生活源总磷污染及治理特征。结果表明,2016—2019年,长江经济带工业源和生活源总磷排放量总体下降,但占全国比例逐年增加。工业源涉磷企业主要分布在江苏、浙江、四川、湖北等省,主要涉及纺织、农副食品、化工、电镀等行业;下游的南通、苏州、宁波、绍兴和杭州等城市"三磷"企业总磷产生量也较大。工业源总磷治理存在污水处理设施建设和现有治理能力不足的问题。四川、江苏、湖南等地的生活源总磷排放量较大,贵州、江西、云南等地的人均总磷排放量较高。长江经济带上游流域、地区生活污水处理率、总磷去除率较低。建议加强工业源涉磷企业监管和治理力度,强化上游地区生活污水处理设施建设和提标改造,减少总磷污染。     

湖州合溪新港污染物入湖通量估算与分析

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。     

城市水质指数法在地表水环境质量评价中的应用

城市水质指数法能够量化、直观地反映不同流域、地区或城市的地表水环境质量,运用城市水质指数法测算了江苏省不同流域或地区的城市水质指数。结果表明,相应时段内苏南城市地表水水质略优于苏北城市;长江流域地表水水质优于淮河流域;城市水质指数变化程度(△CWQI)的统计结果基本为负值,表明江苏省地表水环境质量整体呈改善趋势;长江流域a市△CWQI为正值,表明该市2020年上半年水质较去年同期有所下降;淮河流域总磷水质指数波动范围最大,该流域总磷污染问题较突出,与水质监测结果总体相符。大量数据测算发现,城市水质指数法在应用到地表水环境质量排名时存在数据修约、方法检出限、断面统计基数及现状与变化程度排名倒挂等问题,针对不同问题提出相应的解决方法与对策建议,以期为相关主管部门提供参考与决策依据。     

Design and model based inferences with applications to acidification of lakes in eastern Canada

The design and model based approaches for making inferences about the number of lakes affected by acidic deposition and the chemical characteristics of aquatic resources at risk are described. In many instances when the lakes in the sample are selected for convenience without any randomization, the model based approach continues to provide valid inferences about the population of lakes. The performances of the two approaches are compared using a small population of 177 lakes which are located in southern Quebec. Examples from the Canadian acid rain monitoring program in the Atlantic provinces are also given.     

基于多元统计分析的石头口门水库汇水流域水质综合评价

根据石头口门水库汇水流域的4个监测断面2001～2007年的水质监测数据,应用多元统计分析方法(聚类分析与因子分析)确定主要污染因子并计算权重,从而对流域的水质进行综合评价。结果表明,通过因子分析,提取了3个公因子,第一主因子主要包括溶解氧、氨氮、总氮、高锰酸盐指数、化学需氧量、生化需氧量;第二主因子的主要代表指标是总磷;氟化物、总大肠菌群数对第三主因子贡献明显。由综合评价结果得出,石头口门水库总体属Ⅲ类水质,主要污染因子为总磷;饮马河(烟筒山断面)和岔路河(星星哨水库断面)水质属Ⅲ类,主要受第一主因子影响;双阳河(新安断面)水质属Ⅴ类。流域水质主要受到了农业非点源污染和生活污染的影响。     

漳河上游流域沉积物中磷的空间分布特征及其影响因素

漳河上游地区众多的水利工程改变了流域水循环,同时也影响了河流泥沙和生源物质的循环过程。为揭示人类活动干扰下的沉积物中磷的赋存特征,采用改进后的连续化学萃取法分析了漳河上游沉积物中总磷(TP)和磷形态的空间分布特征及其影响因素。研究结果表明,漳河上游沉积物中的TP含量为405.94~899.98 mg/kg,低于我国其他主要河流,接近我国东部平原湖泊含量水平。漳河上游的TP富集指数(PEI)均值为1.15,表明漳河上游富营养化风险较高。可交换态磷(Ex-P)、铁锰螯合态磷(BD-P)、铁铝氧化态磷(NaOH-P)、钙结合态磷(HCl-P)分别占沉积物中TP含量的1.13%、33.96%、12.99%、35.05%。BD-P和HCl-P是沉积物中主要的磷形态,Ex-P的含量最低,NaOH-P的含量波动最大。漳河上游沉积物中,生物可利用磷(BAP)的含量约占TP含量的38.36%~52.04%,其中,清漳干流的BAP含量明显低于其他河段。清漳源头的水土流失及浊漳河的磷输入对漳河上游BAP含量的贡献较大。统计分析显示,漳河上游表层沉积物中,TP和磷形态的空间分布无显著差异,表明以水利工程建设为代表的强烈人类活动对漳河上游沉积物中磷的空间分布的影响不显著。相关性分析和冗余分析表明,沉积物中的NaOH-P含量与沉积物中黏土和粉土的占比有较高的相关性,BD-P和NaOH-P是控制沉积物中BAP构成的重要因素,Fe含量是沉积物中TP含量的主控因子。     

Heavy Metal Transport and Behavior in the Lower Columbia river, USA

The primary objective of this study was to evaluate temporal changes in heavy metal content of lower Columbia River sediment following terminated or reduced soluble heavy metal loading from the world's largest lead-zinc refinery and mining districts in the USA and Canada. Sediment cores were collected from two fine sediment depositional sites (∼600 km downstream) in August 1999 and were analyzed for total metal content, texture, and age/dating parameters. Zinc, cadmium and lead contents in 1999 declined by only a factor of two over their depth profile maxima (dated as between 1970 and 1980). In sharp contrast, more than a 10-fold decrease in dissolved metal loading occurred during this same period. Zinc in filtered Columbia River water at downstream locations also declined by > 10-fold, consistent with the reduced upper river solute-metal loading. Once soluble metal releases are reduced or terminated, the solute half-time in Columbia River water is months versus ∼20 yr for adsorbed metals on surficial (or resuspended) bed sediments. The much slower rate of decline for sediment, as compared to the solute phase, is attributed to resuspension, transport and redeposition of irreversibly bound metals from upstream sedimentary deposits. This implies downstream exposure of benthic or particle-ingesting biota can continue for years following source remediation and/or termination of soluble metal releases. Accordingly, contaminant contents of both particulate and solute phases of river water, as well as sediment core sections, are suggested for assessing long-term biotic exposure/response to mitigation activities in the Columbia River and similar fluvial ecosystems.     

古泊善后河水质污染特征及污染来源调查

以2016—2020年古泊善后河国家和省级地表水监测网水质例行监测数据为依据,采用水质指数法(WQI)对古泊善后河水质污染状况进行综合评价;基于水质评价结果,选取影响最大的两项指标COD_Mn和TP,于2020年10月对古泊善后河开展加密监测,调查分析污染来源。结果表明,2016—2020年古泊善后河水质波动变化较大,汛期降雨对水质下降影响明显,COD_Mn、TP、COD_Cr、氟化物和BOD₅是影响古泊善后河水质的主要指标;加密监测期间,古泊善后河干流水质COD_Mn和TP指标浓度分别升高28.9%、38.3%,其中宿迁段升幅显著高于连云港段;支流水质超Ⅲ类比例为22.9%,劣Ⅴ比例为6.3%;部分乡镇生活污水直排和持续降雨将农田中高浓度污染物冲刷进河流支浜,是导致水质下降的主要原因。