Design of sampling locations for river water quality monitoring considering seasonal variation of point and diffuse pollution loads

The design of a water quality monitoring network (WQMN) is a complicated decision-making process because each sampling involves high installation, operational, and maintenance costs. Therefore, data with the highest information content should be collected. The effect of seasonal variation in point and diffuse pollution loadings on river water quality may have a significant impact on the optimal selection of sampling locations, but this possible effect has never been addressed in the evaluation and design of monitoring networks. The present study proposes a systematic approach for siting an optimal number and location of river water quality sampling stations based on seasonal or monsoonal variations in both point and diffuse pollution loadings. The proposed approach conceptualizes water quality monitoring as a two-stage process; the first stage of which is to consider all potential water quality sampling sites, selected based on the existing guidelines or frameworks, and the locations of both point and diffuse pollution sources. The monitoring at all sampling sites thus identified should be continued for an adequate period of time to account for the effect of the monsoon season. In the second stage, the monitoring network is then designed separately for monsoon and non-monsoon periods by optimizing the number and locations of sampling sites, using a modified Sanders approach. The impacts of human interventions on the design of the sampling net are quantified geospatially by estimating diffuse pollution loads and verified with land use map. To demonstrate the proposed methodology, the Kali River basin in the western Uttar Pradesh state of India was selected as a study area. The final design suggests consequential pre- and post-monsoonal changes in the location and priority of water quality monitoring stations based on the seasonal variation of point and diffuse pollution loadings.     

Critical Sampling Points Methodology: Case Studies of Geographically Diverse Watersheds

Only with a properly designed water quality monitoring network can data be collected that can lead to accurate information extraction. One of the main components of water quality monitoring network design is the allocation of sampling locations. For this purpose, a design methodology, called critical sampling points (CSP), has been developed for the determination of the critical sampling locations in small, rural watersheds with regard to total phosphorus (TP) load pollution. It considers hydrologic, topographic, soil, vegetative, and land use factors. The objective of the monitoring network design in this methodology is to identify the stream locations which receive the greatest TP loads from the upstream portions of a watershed. The CSP methodology has been translated into a model, called water quality monitoring station analysis (WQMSA), which integrates a geographic information system (GIS) for the handling of the spatial aspect of the data, a hydrologic/water quality simulation model for TP load estimation, and fuzzy logic for improved input data representation. In addition, the methodology was purposely designed to be useful in diverse rural watersheds, independent of geographic location. Three watershed case studies in Pennsylvania, Amazonian Ecuador, and central Chile were examined. Each case study offered a different degree of data availability. It was demonstrated that the developed methodology could be successfully used in all three case studies. The case studies suggest that the CSP methodology, in form of the WQMSA model, has potential in applications world-wide.     

Optimization models for siting water quality monitoring stations in a catchment

A water quality monitoring network (WQMN) must be designed so as to adequately protect the water quality in a catchment. Although a simulated annealing (SA) method was previously applied to design a WQMN, the SA method cannot ensure the solution it obtained is the global optimum. Therefore, two new linear optimization models are proposed in this study to minimize the deviation of the cost values expected to identify the possible pollution sources based on uniform cost (UC) and coverage elimination uniform cost (CEUC) schemes. The UC model determines the expected cost values by considering each sub-catchment being covered by which station, while the CEUC model determines the coverage of each station by eliminating the area covered by any upstream station. The proposed models are applied to the Derchi reservoir catchment in Taiwan. Results show that the global optimal WQMN can be effectively determined by using the UC or CEUC model, for which both results are better than those from the SA method, especially when the number of stations becomes large.     

Developing an environmental water quality monitoring program for Haraz River in Northern Iran

Water quality management plans are an indispensable strategy for conservation and utilization of water resources in a sustainable manner. One common industrial use of water is aquaculture. The present study is an attempt to use statistical analyses in order to prepare an environmental water quality monitoring program for Haraz River, in Northern Iran. For this purpose, the analysis of a total number of 18 physicochemical parameters was performed at 15 stations during a 1-year sampling period. According to the results of the multivariate statistical methods, the optimal monitoring would be possible by only 3 stations and 12 parameters, including NH₃, EC, BOD, TSS, DO, PO₄, NO₃, TDS, temperature, turbidity, coliform, and discharge. In other words, newly designed network, with a total number of 36 measurements (3 stations × 12 parameters = 36 parameters), could achieve exactly the same performance as the former network, designed based on 234 measurements (13 stations × 18 parameters = 234 parameters). Based on the results of cluster, principal component, and factor analyses, the stations were divided into three groups of high pollution (HP), medium pollution (MP), and low pollution (LP). By clustering the stations, it would be possible to track the water quality of Haraz River, only by one station at each cluster, which facilitates rapid assessment of the water quality in the river basin. Emphasizing on three main axes of monitoring program, including measurement parameters, sampling frequency, and spatial pattern of sampling points, the water quality monitoring program was optimized for the river basin based on natural conditions of the study area, monitoring objectives, and required financial resources (a total annual cost of about US $2625, excluding the overhead costs).     

Industrial air pollution by metals monitored by a synthetic fabric: A case study of a community

To supplement an epidemiological investigation into respiratory cancer, a synthetic fabric called tak was used to study the deposition of atmospheric metal pollution within the town of Armadale, central Scotland. Pollution maps showed high concentrations of several metals in areas close to the town's steel foundry and in a second area in the north of the town. Through further statistical analyses, those metals were identified which had probably been emitted by the foundry, and temporal variations in metal deposition patterns were examined. The advantages of this method of low technology sampling, which include the low cost and a high density of sampling sites, are described.     

Evaluating the effectiveness of routine water quality monitoring in Miyun reservoir based on geostatistical analysis

This study used geographic information system techniques and geostatistics methods to evaluate the effectiveness of routine water quality monitoring in the western segment of the Miyun reservoir in Beijing. Methodologies as well as the sampling design are evaluated. The single-layer evaluation and three integrated evaluation methods including principal component analysis (PCA), ordinary kriging (OK)_Mean, and Mean_Layers were used to validate the effectiveness of evaluation methods, and the effectiveness of each sampling design was validated by comparing their errors. Results indicated that, while a single-layer evaluation only shows the trophic state of water at a specific level, an integrated evaluation synthetically analyzes and evaluates the trophic state of the entire water body. Furthermore, results of the integrated analysis show that a PCA method is more accurate and can represent the trophic state of the entire water body. The OK_Mean and Mean_Layers methods are only able to represent the mean level for trophic state of the entire water body but cannot reflect local trophic state and distribution details. Although methods used in the routine monitoring of Miyun reservoir have some similarities to the OK_Mean and Mean_Layers methods, their range of errors and uncertainty are greater because of a lack of detailed spatial continuous information. The analysis on the number of sampling points shows that, within a certain range of error, minor changes of sampling points will have no obvious impact on the monitoring results. For the routine monitoring of western Miyun reservoir, using only three to five sampling points for monitoring is inadequate. According to our analysis, it is more appropriate to use at least ten sampling points for monitoring these areas.     

长沙市某集中式饮用水水源地周边土壤重金属污染特征和风险评价

以长沙某河库兼用型饮用水水源地一、二级保护区土壤为研究对象,于2018年8月采用网格布点法在一级和二级保护区分别布设3个和7个采样点,在水源地历史采样区布设5个采样点,探究土壤中Cd、Pb、Cr、Cu、Zn、Ni、Hg、As的含量分布及污染水平.结果表明:土壤中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的含量均值分...     

基于DPeRS模型的渭河典型断面汇水区面源污染评估及污染成因分析

近年来甘肃渭河桦林断面月度水质不稳定达标的问题引起了管理部门的广泛关注,掌握桦林断面汇水范围面源污染现状,对控制流域面源污染和促进水质稳定达标具有重要意义。采用遥感分布式污染估算（DPeRS）面源污染评估模型,对2018年黄河流域甘肃桦林断面汇水区面源污染空间分布特征进行分析,开展多类型污染量产排特征解析。结果表明：农业面源污染量方面,2018年甘肃桦林断面汇水区总氮（TN）、总磷（TP）、氨氮（NH⁺₄-N）、重铬酸盐指数（COD_Cr）面源污染排放量分别为11 591,2 697,7 141和1 458 t,入河量分别为2 184,512,1347,263 t;空间分布上,氮型（TN和NH⁺₄-N）排放负荷高值区主要分布在陇西县、武山县县段和岷县县段;武山县县段TP排放负荷较为突出;COD_Cr型面源污染高负荷区主要分布在陇西县、渭源县县段和武山县县段。农业面源污染物入河排放负荷空间分布差异明显,氮磷型（TN、NH⁺₄-N和TP）入河高负荷区主要分布在武山县县段、陇西县、临洮县县段;COD_Cr型面源污染入河高负荷区呈分散分布。漳县西部地区水土流失量较高,漳县西部、陇西县和渭源县县段北部局部地区泥沙负荷量较高。枯水期污染治理仍是保障水质稳定达标的关键期,农田径流是渭河桦林断面所在汇水区氮磷型面源污染的首要污染类型,畜禽养殖是COD_Cr型面源污染的首要污染类型。     

沱江流域主要污染负荷预测及时空分布特征

耦合社会-经济因子探究工业点源和生活污染源污染负荷未来变化趋势,可为优化水环境规划和管理方案提供理论依据。选取沱江流域为研究区域,采用经济增长预测法、工业点源传统统计法、人口趋势灰色模型预测法和排污系数法分别计算了2020-2025年该区域28个县(市、区)的工业GDP值,工业点源废水排放量及主要污染负荷(COD、NH₃-N、TN、TP),农村与城镇人口及生活污染源的主要污染负荷,并利用ArcGIS技术探究了工业点源和生活污染源主要污染负荷空间分布特征。结果表明:2020-2025年,工业GDP值总体呈逐年增加趋势,而工业废水排放量总体呈逐年减少趋势,预计到2025年,流域工业GDP值将增加至2.52×10¹²元,而工业废水排放量将减少至0.64×10⁸ t。工业点源主要污染负荷表现为COD>NH₃-N>TN>TP。沱江流域总人口数与生活污染源污染负荷呈逐年增加趋势,其中城镇人口与生活污染源污染负荷呈逐年增加趋势,农村人口与生活污染源污染负荷呈逐年减少趋势,且城镇人口及生活污染源污染负荷增加量大于农村人口及生活污染源污染负荷减少量。城镇、农村生活污染源的主要污染负荷表现为COD>NH₃-N>TN>TP。工业点源和生活污染源主要污染负荷在空间上存在高度异质性。2025年,来自工业点源的主要污染负荷均呈上游较少,中、下游较多的特征;来自城市生活污染源的主要污染负荷均呈中、上游较多,下游较少的特征;来自农村生活污染源的主要污染负荷均呈中游较多,上、下游较少的特征。笔者提出耦合社会-经济因子预测流域污染负荷的方法可以推广到其他与社会经济指标相关联的流域工业点源、生活污染源污染负荷的预测研究中,以期为未来流域水环境管理与治理提供科学参考。     

Tailoring groundwater quality monitoring to vulnerability: a GIS procedure for network design

Monitoring networks aiming to assess the state of groundwater quality and detect or predict changes could increase in efficiency when fitted to vulnerability and pollution risk assessment. The main purpose of this paper is to describe a methodology aiming at integrating aquifers vulnerability and actual levels of groundwater pollution in the monitoring network design. In this study carried out in a pilot area in central Italy, several factors such as hydrogeological setting, groundwater vulnerability, and natural and anthropogenic contamination levels were analyzed and used in designing a network tailored to the monitoring objectives, namely, surveying the evolution of groundwater quality relating to natural conditions as well as to polluting processes active in the area. Due to the absence of an aquifer vulnerability map for the whole area, a proxi evaluation of it was performed through a geographic information system (GIS) methodology, leading to the so called “susceptibility to groundwater quality degradation”. The latter was used as a basis for the network density assessment, while water points were ranked by several factors including discharge, actual contamination levels, maintenance conditions, and accessibility for periodical sampling in order to select the most appropriate to the network. Two different GIS procedures were implemented which combine vulnerability conditions and water points suitability, producing two slightly different networks of 50 monitoring points selected out of the 121 candidate wells and springs. The results are compared with a “manual” selection of the points. The applied GIS procedures resulted capable to select the requested number of water points from the initial set, evaluating the most confident ones and an appropriate density. Moreover, it is worth underlining that the second procedure (point distance analysis [PDA]) is technically faster and simpler to be performed than the first one (GRID?+?PDA).     

Wmo's activities on background atmospheric pollution and integrated monitoring and research

As early as 1968, WMO decided to start a programme on atmospheric pollution. Consequently, a Panel of Experts on Meteorological Aspects of Atmospheric Pollution was established. It was also decided to operate a network of background air pollution monitoring stations. With increasing public concern on environmental pollution impacts, a growing number of WMO Members joined the programme. The Environmental Pollution Monitoring and Research Programme, as well as the World Climate Programme launched in the late seventies, will provide information on a possible influence of pollution on climate.When the network of background ait pollution monitoring started, some Members had already proposed to carry out multimedia monitoring at suitable stations. Later on, it became obvious that more information is required on levels and trends of pollutants in media interacting with the atmosphere and a project on integrated monitoring was established, the purpose of which is to define the objectives and uses of integrated monitoring and to establish procedures for routine standardized integrated monitoring of the of the environment.Pilot projects presently being carried out in a few Member countries are meant to provide most of the information required for the implementation of global background integrated environmental monitorting.     

广州市流溪河水库监测布点优化研究

运用方差分析及模糊聚类分析,对流溪河水库监测布点进行优化研究,结果表明：水库水质良好,各监测点间及垂向采样点间均无显著性差异;4个库区监测点可分为3类,其余监测点可分为4类。综合考虑确定流溪河水库监测布点方案,应设置对照、控制、出水3类断面,共7个监测点,分别为玉溪河、吕田河、汇水区、库区3个和大坝监测点,每年6月进行垂向分层采样,其余月份进行表层采样。     

Calculating of river water quality sampling frequency by the analytic hierarchy process (AHP)

River water quality sampling frequency is an important aspect of the river water quality monitoring network. A suitable sampling frequency for each station as well as for the whole network will provide a measure of the real water quality status for the water quality managers as well as the decision makers. The analytic hierarchy process (AHP) is an effective method for decision analysis and calculation of weighting factors based on multiple criteria to solve complicated problems. This study introduces a new procedure to design river water quality sampling frequency by applying the AHP. We introduce and combine weighting factors of variables with the relative weights of stations to select the sampling frequency for each station, monthly and yearly. The new procedure was applied for Jingmei and Xindian rivers, Taipei, Taiwan. The results showed that sampling frequency should be increased at high weighted stations while decreased at low weighted stations. In addition, a detailed monitoring plan for each station and each month could be scheduled from the output results. Finally, the study showed that the AHP is a suitable method to design a system for sampling frequency as it could combine multiple weights and multiple levels for stations and variables to calculate a final weight for stations, variables, and months.     

基于监测成本收益分析的重点污染源筛选方法研究

对目前国家污染重点监控污染源筛选方法现状进行总结分析,从经济学角度提出运用成本收益分析方法。在考虑监测成本的前提下计算重点污染源单因子筛选比例的方法,是对累积污染负荷法的改进和补充,使国家重点污染源的筛选更为经济且科学有效。     

Linking Hydrogeological and Ecological Tools for an Integrated River Catchment Assessment

Ecological (biological and hydrochemical assessment) and hydrogeological (vulnerability and pollution risk mapping) tools have been combined to assess the ecological quality and hydrogeological vulnerability of an agricultural river basin. In addition, the applicability of the recently developed vulnerability assessment approach (COP method) in the particular environmental conditions was tested by comparing its results with hydroecological assessment tools (i.e., pollution metrics). Five sampling sites were selected and sampled for benthic macroinvertebrates and physicochemical variables during summer and spring. Overall, sites ranged from moderate to poor ecological quality. The results illustrated that 26% of the study area was of moderate pollution risk, while 65% was classified as of low and very low risk zones. However, the higher elevation zones where calcareous rock formations are encountered presented moderate to high pollution risk that was accredited by the ecological quality assessment. Pollution metrics facilitated from hydrochemical analysis indicated a significant association with groundwater vulnerability, thus validating vulnerability and risk estimations. This study indicated that the particular groundwater pollution risk mapping methodology and the water quality assessment indices can be well combined to provide an integrated evaluation tool at a catchment scale.     

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。     

成都大气污染物在焚烧秸秆时的溯源初步探究

在空气污染指数(API)的数据基础上,结合卫星遥感、气团后向轨迹及气象数据,通过初步分析秸秆焚烧对本地及区域范围输送对城市空气质量影响,研究不同空气污染类型(本地型、本地区域相结合型、输送型)特征,探索重污染条件的大气污染物溯源方法。     

Multivariate analysis of drinking water quality parameters in Bhopal, India

Pollution of water bodies is one of the areas of major concern to environmentalists. Water quality is an index of health and well being of a society. Industrialization, urbanization and modern agriculture practices have direct impact on the water resources. These factors influence the water resources quantitatively and qualitatively. The study area selected were the Upper lake and Kolar reservoir of Bhopal, the state capital of Madhya Pradesh, India. The Upper lake and Kolar reservoir both are the important sources of potable water supply for the Bhopal city. The physico–chemical parameters like temperature, pH, turbidity, total hardness, alkalinity, BOD, COD, Chloride, nitrate and phosphate were studied to ascertain the drinking water quality.     

望虞河西岸河网区沉积物营养盐和重金属污染时空分布特征

以无锡市望虞河西岸河网区为研究区域,于2018年12月—2019年9月分冬、春、夏、秋4个季节采集了上覆水和沉积物样本,研究氮磷营养因子在沉积物-上覆水界面的释放规律,探究主要水质指标、沉积物氮磷和重金属含量的时空分布特征。结果表明:研究区域内的水质状况不佳,主要是氮含量超标,污染严重的点位集中在人类活动较为密集的市区和工业区;受上覆水氮磷浓度、溶解氧浓度等变化的影响,沉积物营养盐含量季节变化明显,污染状况较为严重,75%的点位属于中度和重度污染;沉积物重金属含量季节变化不显著,部分重金属的空间分布特征相似,污染程度排序为Zn>Cd>Cu>Pb>Ni>Cr>As。     

船载自动监测系统在水质监测中的应用

水质监测是开展水生态环境评价、监管的基础性工作之一。随着对水生态环境保护与管理要求的提高,人工水质监测与自动水质监测相结合的模式应用越来越普遍。以船舶为载体的水质自动监测系统开展巡测,可实现高密度样品采集、检测及信息的实时传输,在长江泸州以下干流水域的实践中取得了良好效果。系统的应用可弥补常规监测断面间距过大、人工监测频次低、固定站房式水质自动监测站近岸取样等不足,对人工监测和自动监测形成有效补充;船载水质自动监测系统能够实现定点、定深、定时监测,可以在河流污染带监测、入河排污行为的监管以及偷排行为的溯源、水污染应急动态监测等工作中发挥有效作用,既可应用于长江干流等河道较宽且水质可能存在岸别差异的河流,也可应用于滇池、太湖、丹江口等大型湖泊、水库水生态环境监管。