Water Quality Grade Research Articles

Application of improved extension evaluation method to water quality evaluation

The extension evaluation method (EEM) has been developed and applied to evaluate water quality. There are, however, negative values in the correlative degree (water quality grades from EEM) after the calculation. This is not natural as the correlative degree is essentially an index based on grades (rankings) of water quality by different methods, which are positive. To overcome this negativity issue, the interval clustering approach (ICA) was introduced, which is based on the grey clustering approach (GCA) and interval-valued fuzzy sets. However, the computing process and formulas of ICA are rather complex. This paper provides a novel method, i.e., improved extension evaluation method, so as to avoid negative values in the correlative degree. To demonstrate our proposed approach, the improved EEM is applied to evaluate the water quality of three different cross-sections of the Fen River, the second major branch river of the Yellow River in China and the Han Jiang River, one of the major branch rivers of the Yangtse River in China. The results of the improved evaluation method are basically the same as the official water quality. The proposed method possesses also the same merit as the EEM and ICA method, which can be applied to assess water quality when the levels of attributes are defined in terms of intervals in the water quality criteria. Existing methods are mostly applicable to data in the form of single numeric values.

Effects of pollution on macroinvertebrates and water quality bio-assessment

Many large rivers in China have an inflow of contaminated water. Water pollution caused by urban sewage and agriculture, and occasionally pollution events from industries have become a significant stress on aquatic ecology. Pollution affects the biodiversity of the aquatic community and the species composition changes from natural species to tolerant species. The species composition of aquatic animals may reflect water pollution level. Extremely non-uniform distributions of functional feeding groups occurred as a result of high nutrient levels. A combination of chemical and biological methods constitutes the best approach for biological monitoring studies that measure water quality. Macroinvertebrates were used as bio-assessment indicator to determine the environmental quality of given water body. In this study, samples of water and macroinvertebrates were taken from several dozen sites in 14 rivers in China with different pollution levels, including the Yangtze, East, Weihe, Songhua, Yongding, and Panlong rivers. Macroinvertebrates were identified to genus or family level. Water samples were classified into different water quality grades according to the concentration of different substances. Five biological indices: taxa richness (S), density (D), total BMWQ score (t-BMWQ), average BMWQ score (a-BMWQ), and the family biotic index (FBI) were used for biological assessment of water quality. Analyzing macroinvertebrates’ occurrence in different water quality levels, taxa-specific indicators, which are defined as the taxa of macroinvertebrates that live in a certain water quality level but do not exist in other water quality levels were proposed for water quality bio-assessment. Leptophlebiidae, Siphlonuridae, Arctopsychidae, Perlidae, and Antocha sp. are the taxa-specific indicators for very good or good water quality; Chironomidae, Lymnaeidae, Tubifex sp., Limnodrilus sp., Limnoperna lacustris, Corbicula sp., Macrobrachium sp., Planorbidae, Glossiphoniidae, and Branchiura sp. are the taxa-specific indicators for very poor water quality; and Psychomyiidae and Hydroptilidae are the taxa-specific indicators for moderate water quality.

Application of Bayesian Theory to Water Quality Comprehensive Assessment

According to many uncertain problems of current water quality comprehensive assessment, a Bayesian model for water quality evaluation was established based on the basic principles of Bayesian formula. Select monthly monitoring data for 5 parameters at 15 different monitoring sections, generated from July 2006 to June 2007 and use Chinese GB3838-2002 as evaluation standards to analyze the water quality grade in this study. The annual evaluation results show that the water quality of ChangLe River mainly belongs to Ⅲ and Ⅳ grade. The monthly water quality has a certain relation with rainfall. The Bayesian method has the characteristic of more integrated, suitable for both large and small samples, simple calculation and easily to be used widely.

낙동강 유지용수 공급 후 온천천의 수질 및 생물변화 특성

낙동강 유지용수가 공급되고 있는 온천천을 대상으로 2009년 10월부터 2010년 10월까지 수질 및 생물학적 인자변화를 조사하였다. 조사결과 온천천은 BOD, TN, TP 그리고 중금속 농도가 낙동강 유지용수가 공급되기 이전인 2005년에 비해 뚜렷하게 감소한 것으로 나타났으며, 특히 BOD 평균농도가 2.0 mg/l로 모든 지점이 2급수를 유지하였다. 또한 온천천 수중에 존재하는 플랑크톤과 저서성 대형 무척추동물의 종 및 개체수도 증가한 것으로 조사되었다. 결론적으로 낙동강 유지용수가 공급된 이후에 온천천은 수질 및 생물변화와 같은 물 환경인자가 상당히 개선되었음을 알 수 있었다. This study investigated the changes caused by diverting water applications at the riverhead of the Onchun Stream via the monitoring of several water quality and biological parameters between 10/09 and 10/10. The analysis indicated that the Onchun Stream distinctly decreased in terms of several water quality parameters, such as BOD, COD, TN, TP, and the concentration of heavy metals as compared to similar values in 2005, before the flowing of the Nakdong River. Especially, BOD showed the 2nd grade of water quality, with an average of 2.0 mg/l at all sites. The species number and standing crops of plankton and benthic macroinvertebrates in the Onchun Stream were also increased. Thus, it was concluded that diverting water from the Nakdong River to the Onchun Stream dramatically improved various environmental indices, such as water quality and biological changes.

Application of Triangle Relational Degree Model for Evaluation of Lake Eutrophication

Aiming at the problem being too complex for the present evaluation methods on lake eutrophication, a new method, triangle relational degree model was used to solve the complicated non-linear relation between the evaluation factors and water quality grade. The model was applied to evaluate the lake eutrophication and the results of the assessment are in concordance with other evaluation methods. Compared with the other evaluation method, this model is perfect, the evaluating result is more reasonable and its resolving power is higher. Thus, a simple and effective method is provided for lake eutrophication evaluation.

The Construction of Inference Engine for Meaningful Context and Prediction Based on USN Environment

Currently, with gradually increasing movement to live with nature, artificial wetlands are increasing as well. All these change blows at rivers and streams thereby need for wetland management systems to increase. To measure environmental situations on the wetlands, people should go outside and check with measurement tools regularly. However, with these tools only it is difficult to know the exact situations on that wetland. Thus, we attached various sensors on the wetland and made sensor network environment. We used sensing data from sensor network to assume the situation of the wetland. This paper proposes a design for this through application of context inference of USN (Ubiquitous Sensor Network) and inference production rules for context inference engine of wetland management system by using JESS. In this study, we made rules using actual eutrophication criteria as a standard of water quality. The produced rules in this paper can decide the grade of eutrophication on wetland environment then predict the status of the wetland based on facts collected from sensor networks. Sensors sense data such as DO, BOD, SS, PH. And production rules divided the grades of each fact and then final rules can decide the eutrophication grades which mean water quality grades.

A Water Quality Monitoring Method Based on Fuzzy Comprehensive Evaluation in Wireless Sensor Networks

A novel water quality monitoring method named WQMMFCE is proposed based on fuzzy comprehensive evaluation model to solve the issue of high energy consumption caused by centralized approach under the background of water quality monitoring. The weights of all factors which are necessary for fuzzy comprehensive evaluation can be obtained firstly by using the binary expert evaluation. The information needs to transmit is decided according to water quality grade which is quantitatively analyzed directly by using fuzzy comprehensive evaluation rather than transmitting large amount of raw data to the monitoring center. Simulation result shows that the method has a great advantage over the centralized one on energy saving and can prolong the lifetime of the network.

소양호 유역의 유출특성에 의한 유달오염부하량 산정

본 연구는 소양호 상류유역을 선정하여 2008년, 2009년 2년 동안 강우시와 비강우시 유량과 수질을 조사하여 유출량에 따른 수질농도가 변화하는 양상을 고찰하였다. 유량가중평균농도를 이용하여 수질등급을 비교한 결과, 비강우시 기간에 1~2등급의 수질등급을 보이다가 강우시 기간에는 3급수 이하로 수질상태가 악화되는 것을 확인하였으며, 초기 강우시에 오염물질의 유출이 크게 발생하며 유량이 증가하면서 강우에 의한 희석효과로 오염물질 배출이 작게 지속적으로 발생하였다. 또한 회귀분석을 통하여 배수구역별 유출량에 따른 오염부하량의 회귀식을 제안하였으며, 연간 유출량비를 이용하여 배수구역의 연간 유달오염부 하량을 산정하였다. This study selected the upstream of Soyang Lake and investigated the flow and water quality during rainfall and non-rainfall periods in 2008 and 2009 and inquired into the changing conditions of concentration of water quality depending on runoff capacity. Water quality grades were compared, using FWMC and as a result, it was confirmed that the first and second grades during the non-rainfall period and the water condition aggravated below the third grade during the rainfall period. And as the flow gained due to a great increase in the discharge of contaminated substances during the early rainfall period, small amounts of contaminated substances occurred continuously. Also, this study suggested regression equation of pollution load depending on the flow in each drainage area through regression analysis and computed annual delivery pollution load in drainage areas, using annual rate of runoff capacity.

A Comparative Study of USA and Canadian Water Quality Index Models

The US-based water quality index models originated from the National Sanitation Foundation (NSF) in additive (AWQI) and multiplicative (MWQI) forms in the early 1970s. The other model which has gained popularity in the recent years is Oregon Water Quality Index (OWQI) which is based on the harmonic averaging concept. The Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) (also referred to as Canadian Water Quality Index, CWQI in the text) was commissioned in 2001 to assess the water quality of surface waters across Canada. The United Nations Environmental Program (UNEP) has endorsed the CCME WQI (or CWQI) model suitable for grading the quality of drinking waters world wide. The index scores from all the models range from 0 to 100, higher scores alluding to better quality. The water quality is categorized in five grades [excellent, good, fair, marginal, poor], with differential system of ranking while using the index score values. The present study evaluated the water quality data from 30 river sites across the province of Ontario, Canada for 5-year period 2002–04 through 2006–08 (3-year running averages) for the comparison of aforementioned WQI models. The parameters currently used in calculating CCME WQI (or CWQI) score in Ontario are: ammonia, chloride, nitrate, phosphate, chromium, nickel, and zinc (seven parameters). The parameters hardness, pH and temperature are monitored but are used as modifying parameters, i.e., they are taken into consideration by modifying the guidelines or the objective functions of some of the former seven parameters. The study indicated that AWQI and MWQI scores tended to be much higher in comparison to the CWQI scores. As a result, the grades of the water quality for AWQI and MWQI turned out to be superior in relation to CWQI. In contrast, the correspondence in terms of water quality grades between OWQI and CWQI was much closer and better. Overall, the CWQI formulation appeared to be the most stringent, followed by OWQI model to grade the quality of water for the aquatic uses.

부착조류와 유기오탁지수에 의한 소하천의 수질평가

In this study, a method for river water quality evaluation by algal examination was investigated. For development of this method, algae living in small rural streams in Gwangcheon-Cheon were collected and observed by microscope. Samples were collected at six stations from May 2008 to May 2009. To elucidate the relationship between pollution and the algal species, diatom grasps were collected from the streams and used to determine the water quality grade. The numerical EC value was compared with the value of DAIpo (Diatom Assemblage Index of Organic Water Pollution), and the results showed a tendency to a mutually inverse relationship. Further, the numerical BOD and COD values were compared to the DAIpo value. The results showed that, various diatoms reside in Gwangcheon-Cheon, and water quality was found to be second-grade at all the examined points. These results indicate pollution of streams by livestock wastewater; however continuous monitoring will be necessary to more definitely determine the reason for the Gwangcheon-Cheon pollution.

Use of geographic information system in the assessment of bacteriological quality and sanitary risk factors of household drinking water sources in Ibadan, Nigeria

This study used a combination of Geographic Information System (GIS), bacteriological analysis and sanitary inspections to assess the risk of contamination of drinking water sources in 62 randomly selected households in Ibadan, Nigeria. Findings revealed that the majority of the households used groundwater sources of poor quality. The raw bacteriological data was classified into five water quality Grades A to E (from no risk to very high risk). Majority (82.3%) of the households were grouped as D and E, implying that a large proportion of the households was exposed to high bacterial load in their water supplies thus exposing these households to the risk of water-borne diseases. Results of sanitary inspection also showed that most (62.9%) households have intermediate/high risks associated with physical defects in the water supply facilities which could lead to quality deterioration. A weak positive correlation (Spearman's r =0.379, p =0.02) was observed between the E. coli and sanitary risk score grades. The study proposed urgent remedial action by all stakeholders and an extension of the study to cover the rural and urban local government areas in Ibadan.

Groundwater Quality and the Settlements Condition in

To comprehend the factors which influence on the juvenile water, it needs paying attention to the rocks permeability, the thickness of the aeration zone, the type of the material composition and the depth of the ground water. The grade of the ground water quality, both ground water in general and juvenile water in the urban, is dependent upon the natural physical, man made physical, and the condition of the local inhabitant besides the another factors. The influence grade of the factors are undersirable yet because among of them there are cross-linkages. The linkage of the ground water quality condition, besides another factor, inconfirmed by the inhabitant and the settelement. The aspect of the man made physical, both sanitation condition and the population density with their activity effect i.e. sewage by product, should fully determine the ground water quality. There is a closed connection between the juvenile water quality and the settlement condition, mainly, in the case is the domestic sewage disposal. It is estimated that the unit of settlement associates with the grade of the juvenile water quality. Some of the variabilities which are desirable to sustain the settlement condition and constitutes the influence variability i.e. the density of the population and buildings, and the condition of the drainage system for sewage.

Improved Grey Situation Decision Making Method for Lake Eutrophicaton Evaluation

将待评价样本作为事件, 水质级别作为对策, 构造局势.通过用效果测度统－计量评价指标, 按级别变量特征值确定最优局势, 提出了用改性灰色局势决策法综合评价湖泊水体富营养化状况并结合实例说明该决策法评价湖泊水体富营养化, 具有客观性和实用性.;This paper studies the practicability and rationality of the application of grey system theory to the assessment of water quality of lakes and proposes the multi-target grey situation decision making method by using grey decision theory.Here, the water sample is taken as an event, the grade of water quality as a strategy, then a situation is set up.By using effect measure to unify the indexes with the grey situation decision making and determining the optimum situation according to the eigenvalues of grade variables, a new method is presented for evaluating eutrophication in lakes.The assessment result of nine lakes' eurtophication shows that it's practicable to assess eutrophication of lakes by using I his method.

Fuzzy expert system to determine stream water quality classification from ecological information

Water quality classification for stream has been major tool for water quality management in Korea. This paper examines the application of the fuzzy inference mechanism to develop a fuzzy expert system for proper determination of WQCS from uncertain and imprecise ecological information. This study proposes a rule matrix composed of seven water quality grades, toxicity of water and rarity of cases. From this rule matrix, 30 rules for WQCS determination are generated. From the comparison of performance of the fuzzy expert system and the conventional expert system for the determination of class, toxicity, and rarity, it seems that the smoothly varying curves of WQCS determination from the fuzzy expert system represent our real-world experience more realistically than stepwise curves from the conventional expert system.

Fuzzy expert system to determine stream water quality classification from ecological information

Water quality classification for stream has been major tool for water quality management in Korea. This paper examines the application of the fuzzy inference mechanism to develop a fuzzy expert system for proper determination of WQCS from uncertain and imprecise ecological information. This study proposes a rule matrix composed of seven water quality grades, toxicity of water and rarity of cases. From this rule matrix, 30 rules for WQCS determination are generated. From the comparison of performance of the fuzzy expert system and the conventional expert system for the determination of class, toxicity, and rarity, it seems that the smoothly varying curves of WQCS determination from the fuzzy expert system represent our real-world experience more realistically than stepwise curves from the conventional expert system.

The EEC bathing water directive

In June 1977 the French Minister of Culture and the Environment and the Minister of Health and Social Security made it known bacteriological tests on French bathing beaches had shown 77°70 to be of very good or good quality, 19070 of average quality and 4070 of poor quality. Three weeks later, the Central Press Agency of Paris had ferreted out a complete list of the unsatisfactory beaches, 28 of them in all at 23 coastal resorts, and this list was published in the French press and in the Times of 7 July 1977. From 1980 onwards this kind of bacteriological grading of bathing beaches will figure in the reports on bathing waters all member states of the community must submit to the Commission at regular intervals. By then also, no doubt, the tourist interests of the different countries will, in the spirit of fair competition embodied in the Treaty of Rome, blazon abroad their high percentage of good quality beaches and question the validity of competitors' bathing water rankings. The four grades of bathing water quality cited in the French statement are based on conformity or failure to conform to the requirements of the EEC Council 'Directive of 8 December 1975 concerning the quality of bathing water'. This Directive has already been strongly criticized by Lord Ashby (in 1975) because of the spurious uniformity it seeks to impose on bathing beaches from the Mediterranean to the north of Scotland, and also for the enormous cost of implementing it when no significant health hazard from sea bathing has so far been demonstrated. In Britain, the Directive also invites critical scrutiny for another reason. Here, the conclusion based on extensive work over two decades bathing water standards were irrelevant and impracticable has been generally accepted for many years past. Has this been a misguided view? The background to the EEC Directive and its technical aspects are scrutinized from this standpoint in what follows. Perhaps the first significant point emerges from the preamble to the Directive is the EEC was committed to bathing water standards before these were discussed at expert level. The programme of action of the European Communities, promulgated in 1973, included a provision that quality objectives are to be jointly drawn up fixing the various requirements which an environment must meet, inter alia the definition of parameters for water, including bathing water. How to define water quality objectives was the subject of a Service committee studied bathing water contamination in British coastal waters in the nineteen-fifties. He has acted as rapporteur at W H O expert meetings on bathing water hygiene. He is now Chairman of the Joint Committee on the Medical Aspects of Water Quality was set up in 1976 by the Department of Health and Social Security and the Department of the Environment.

宇治川における付着珪藻と水質との関係について

Thirteen samples were collected at four stations in the Uji River, Kyoto, during the period from May 1970 to November 1973. The species identified belong to 33 genera and 165 species in total as benthic diatoms. The values of R. F. of those diatoms which are more than 5% of total 20. Those twenty diatoms can be classified according to the three grades of water quality as follows. Oligosaprobic only : Cymbella tumida, Fragilaria crotonensis, Melosira granulata, M. granulata var. angustissima, M. italica, M. solida and Nitzschia clausi. Both α-oligo and β-mesosaprobic : Cymbella turgidulla, Navvicula cincta, N. cryptocephala and N. cryptocephala var. exilis. Both α-oligo, β- and α-mesosaprobic : Cymbella ventricosa, Gomphonema olivaceum, Nitzschia aciularis and Synedra ulna. β-mesosaprobic : Nitzschia amphibia, N. frustulum and Synedra radians. Both β- and α-mesosaprobic : Synedra rumpens var. familiaris. α-mesosaprobic : Synedra acus.