Projection pursuit cluster model and its application in water quality assessment

One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must be used. In order to overcome this issues the projection pursuit principle is introduced into water quality assessment, and projection pursuit cluster(PPC) model is developed in this study. The PPC model makes the transition from high dimension to one-dimension. In other words, based on the PPC model, multifactor problem can be converted to one factor problem. The application of PPC model can be divided into four parts: (1) to estimate projection index function Q(); (2) to find the right projection direction ; (3) to calculate projection characteristic value of the i th sample z-i, and (4) to draw comprehensive analysis on the basis of z-i. On the other hand, the empirical formula of cutoff radius R is developed, which is benefit for the model to be used in practice. Finally, a case study of water quality assessment is proposed in this paper. The results showed that the PPC model is reasonable, and it is more objective and less subjective in water quality assessment. It is a new method for multivariate problem comprehensive analysis.

Coastal Water Quality Assessment by Self-Organizing Map

A new approach to coastal water quality assessment was put forward through study on self-organizing map （ SOM ）. Firstly, the water quality data of Bohai Bay from 1999 to 2002 were prepared. Then, a set of software for coastal water quality assessment was developed based on the batch version algorithm of SOM and SOM toolbox in MATLAB environment. Furthermore. the training results of SOM could be analyzed with single water quality indexes, the value of N ： PC atomic ratio） and the eutrophication index E so that the data were clustered into five different pollution types using k-means clustering method. Finally, it was realized that the monitoring data serial trajectory could be tracked and the new data be classified and assessed automatically. Through application it is found that this study helps to analyze and assess the coastal water quality by several kinds of graphics, which offers an easy decision support for recognizing pollution status and taking corresponding measures.

Water Quality Assessment of Dachangshan ArtificialHabitat Development Demonstration Area

[Objective] The paper was to evaluate the water quality environment in Dachangshan artificial habitat development demonstration area.[Method] From 2013 to 2015, an environmental survey was conducted for eight voyages in Dachangshan artificial habitat development demonstration area of Changhai County, Dalian City, and 20 hydrochemical indexes including salinity, pH, and COD were monitored. The water quality of thesea area was analyzed by principal component analysis and single factor index method. [Result] Except for that the control area of the August 2014voyage belonged to IIclass sea water standard, the water quality in other stations of all voyages conformed toIclass sea water standard. Totally 20water quality indicators were synthesized into six principal components using principal component analysis, which explained 79.165% of the results;the principal component score was ranged from -1.536 to 3.706; the score in August 2014 was the highest, and the evaluation results were basicallyconsistent with the results of single factor index analysis. [Conclusion] The overall water quality is good in Dachangshan artificial habitat development demonstration area.

Assessment of Water Quality in High-Pressure Peruvian Anthropic Sectors of Lake Titicaca Using a Calibrated Index

The world’s lakes are in the process of degradation, with loss of water quality as a result of anthropic influences. This research aimed to evaluate water quality in high-pressure Peruvian anthropic sectors of Lake Titicaca using a calibrated index. The study considered ten important bays with influence from urban sectors. In each bay, surface waters were monitored for six years, considering physical, chemical and microbiological parameters. Water quality was assessed using the NSF Water Quality Index (NSF-WQI) and the one calibrated for Lake Titicaca (WQIT). Comparing the efficiency of these two indices, the WQIT showed a variation from moderately polluted bays to bad quality bays, such as Desaguadero and Yunguyo. These two bays were classified as hypereutrophic, therefore, the uses attributable to this condition are only irrigation and energy production. Applying the NSF-WQI, the results were not able to identify this significative difference, as all bays were classified as moderate quality waters. This result indicates that the WQIT calibration was adequate, as it allows inferring and estimating the water quality of Lake Titicaca with greater precision. According to Peru’s water quality standard for category 4, established for the conservation of the country’s lakes, the parameters that exceeded the standard values were PO4-P (0.035 mg∙L−1) and BOD5 (5 mg∙L−1) in all bays, and TC (1000 MPN mL−1) in Yunguyo bay. These high values indicate eutrophication processes, one of the main problems in the study area. The WQIT calibrated for Lake Titicaca can be used as an efficient tool to assess water quality in high Andean lentic waterbodies in South America.

Assessment of groundwater suitability for different activities in Toshka district,south Egypt

Globally,groundwater has globally emerged as a crucial freshwater source for domestic,irrigation,and industrial needs.The evaluation of groundwater quality in the Toshka region is imperative to ensure its suitability for the extensive agricultural and industrial activities underway in this promising,groundwater-dependent development area.This is particularly significant as Egypt increasingly relies on groundwater reserves to address freshwater deficits and to implement mega-development projects in barren lands.In this study,fifty-two samples were collected from the recently drilled wells tapping into the Nubian Sandstone Aquifer(NSA)in the Toshka region.Groundwater quality was assessed through hydrochemical analysis,Piper diagram,and various indicators such as Na%,SAR,RSC,KR,MH and PI.The hydrochemical analysis revealed improved groundwater quality characteristics,attributed to continuous recharge from Lake Nasser.The Piper diagram categorised most of the water samples as"secondary salinity"water type.Almost all wells proved suitable for irrigation with only two wells unsuitable based on MH values and six wells based on KR values.Considering Total Hardness(TH)values,all samples were classified as"Soft",indicating their suitability for domestic and industrial purposes.Water Quality Index(WQI)results concluded that all samples met WHO and FAO guidelines for drinking and irrigation,respectively.Spatial distribution maps,constructed using GIS,facilitate the interpretation of the results.Regular monitoring of quality parameters is essential to detect any deviation from permissible limits.

Surface water quality and potential health risk assessments in Changsha-Zhuzhou-Xiangtan section of Xiangjiang River, China

The Changsha-Xiangtan-Zhuzhou City Group is a heavy industrial district and accepted as the serious pollution area in the Xiangjiang River basin.In this study,7 metals(Pb,Hg,Cd,As,Zn,Cu and Se)and the river water quality parameters including pH,dissolved oxygen(DO),Escherichia coli(E.coli),potassium permanganate index(CODMn),dichromate oxidizability(CODCr),five-day biochemical oxygen demand(BOD5),ammonia nitrogen(NH4+-N),total nitrogen(TN),total phosphorus(TP)and fluoride(F)in 18 sampling sites of the Changsha-Xiangtan-Zhuzhou section are monthly monitored in 2016,which is the year to step into the second stage of the“Xiangjiang River Heavy Metal Pollution Control Implementation Plan”.It is found that E.coli,TN and TP are the main pollutants in the Changsha-Zhuzhou-Xiangtan section,and the pollution of heavy metal is not serious but As with potential risk to local people especially children should be concerned.In addition,Xiangtan city is mainly featured with heavy metal pollution,while Zhuzhou and Changsha city are both featured with other pollutants from municipal domestic sewage.

Hydrochemical characteristics and water quality assessment for drinking and agricultural purposes in District Jacobabad,Lower Indus Plain,Pakistan

Undeniably water is of utmost importance while considering basic necessities.This investigation emphasized on the hydrochemical evaluation and drinking water quality assessment in District Jacobabad located in lower Indus plain,Pakistan.Certainly world's largest irrigation system emerged from Indus Basin,which is underlain by well transmissive aquifer resulting in higher water table.Water supply schemes with their water sources from ground water and surface water provide piped water for drinking purpose to the community.Water samples were collected from all the forty eight supply schemes of which thirty two were found nonfunctional.Analytical parameters were compared with World Health Organization(WHO)and Pakistan Water Quality Standards but adversely substantial samples were found nonpotable.Alkalinity,bicarbonate and nitrate met the standard safe limits while values for EC,TDS,hardness,cations and anions exceeded the limits in numerous samples.SPSS and ArcGIS softwares were used for statistical analysis and spatial distribution of parameters.Hydrochemical facies were developed and suitability assessment of water resources was examined for agricultural use.The ground water type was classified as Na-HCO3 type with high salinity and it required treatment prior to irrigation.The proposed research exhibited the probable drinking water contamination sources and it demanded instant actions to further protect the valuable drinking water resources in District Jacobabad.

Water quality assessment of the Shatt al-Arab River,Southern Iraq

Objective:To assess suitability of the water quality of Shatt al-Arab River for protection of aquatic life,potable water supply and irrigation uses.Methods:The Shatt al-Arab River was monitored on a monthly basis from July 2009 to June 2010.A water quality index(WQI)was calculated to assess the suitability of water for protection of aquatic life,potable water supply and irrigation uses during the dry season from July to December 2009 and the wet season from January until June 2010.Results:The results of the WQI showed that the lowest water quality values were scored during the dry season for all three uses of the river.Marginal water quality values were recorded for protection of aquatic life and fair(upstream)to poor(downstream)water quality values were recorded for irrigation uses.Moreover,the river water was not suitable for potable water supply without elaborate treatment.Conclusions:Deterioration of the Shatt al-Arab water quality has been attributed to reduced freshwater discharges from Tigris and Euphrates Rivers,low annual precipitations and an advancing salt wedge from the Arabian Gulf.However,a combination of those factors such as low riverine discharge and advancing salt wedge with a continuous discharge of agriculture,oil industry and urban point effluent has polluted the waters and fostered the decline of the Shatt al-Arab River water quality during the study period.The study indicated that application of WQIs was a useful tool to monitor and assess the overall water quality of the Shatt al-Arab River.

Water Quality Evaluation Index System for Freshwater Aquaculture Pond

[Objective] The aim was to establish the water quality evaluation index system for freshwater aquaculture pond.[Method] The expert survey,DELPHI,field research and other methods were used.Based on the analysis of factors influencing water quality of freshwater aquaculture pond,and the importance degree of 14 factors influencing water quality of freshwater aquaculture pond was ordered.Then,five factors were selected as index to establish the water quality evaluation index system of freshwater aquaculture with the determination for thresholds of these factors.[Result] The importance degree of water quality of freshwater aquaculture pond showed an order of Dissolved oxygenpHPhytoplankton biomassSecchi depthTotal NitrogenZooplankton biomassWater temperatureBiochemical Oxygen DemandWater colorSalinityTotal hardness;according to the value of importance degree,the dissolved oxygen,pH,secchi depth,phytoplankton biomass and total nitrogen these five factors were selected as the index system of water quality evaluation of pond.The level of water quality of freshwater aquaculture pond was divided into five,and the tolerance range of fish to each index was obtained by expert observation.[Conclusion] This study had provided a scientific basis for water quality evaluation system of freshwater aquaculture pond.

Changes in Water Quality of Origin Flows of Hotan River Based on Nemorow Pollution Index

[Objective] The study aimed to analyze water quality of origin flows of Hctan River using Nemorow pollution index method. [Method] Based on data monitored at four monitoring sections of Yorungkash River and Karakash River dudng 2001 -2005, water quality of Hotan River was assessed by using Nemorow pollution index method. [ Result] During 2001 -2005, Yorungkash River and Karakash River had clean water reaching the first standard. Nemorow pollution index was 0.15 -0.69 at the first section of Yorungkash River, and it was 0.23 -0.46 at its last section; there were few changes in water quality at the last section, while Nemorow pollution index showed a downward trend at the first section. Nemorow pollu- tion index was 0.23 -0.65 at the first section of Karakash River, and it was 0.23 -0.47 at its last section, showing a downward trend at its last section. [Condusion] Water quality of Hotan River belonged to first-class clean water.

Applying multivariate statistics for identification of groundwater chemistry and qualities in the Sugan Lake Basin, Northern Qinghai-Tibet Plateau, China

The Sugan Lake Basin is located in the inland arid region of northwestern China,in which groundwater is of great significance to human and ecology.Therefore,it is necessary to understand the chemical characteristics and quality of groundwater in the basin.Based on samples collected from 35 groundwater wells in Sugan Lake Basin,the spatial distribution characteristics of groundwater chemistry,main hydrogeochemical processes and groundwater quality have been discussed in this paper by using the multivariate statistics and hydrochemistry analysis methods.The results showed that the groundwater is weakly alkaline,and its total dissolved solid(TDS)and total hardness(TH) are high,with the average values of 1244.03 mg/L and 492.10 mg/L,respectively.The types of groundwater are mainly HCO_3^--SO_4^(2-)-Ca^(2+)type in the runoff area and Cl^--SO_4^(2-)-Na^+type in the catchment area.Rock weathering and ion exchange are the main controlling factors of regional groundwater chemistry,followed by evaporative crystallization,and human activities have less impact on groundwater.The spatial difference of groundwater quality is obvious,the water quality of the catchment area is not suitable for drinking,and the suitability for plant growth is also poor.The groundwater in the runoff area can be used for drinking,but the hardness is slightly higher,which is more suitable for ecological purpose.

An Analysis of Water Environment Factors and an Evaluation of Water Quantity of Liangzi Lake

The experiments of single factor evaluation method, principal component analysis and voronoi area weighting factor method on the sample data of Liangzi Lake in October 2012 combined with the national surface water environment quality standards can get the map of comprehensive water quality distribution by Kriging interpolation. The analysis shows, the grades of comprehensive water quality gained by three methods are all only class III or class IV, and the quality of water is different from east and west that the water quality of east is better. However, the percent of IV class water is higher in the result of single factor evaluation method means class IV is the main grade of water quality. The result of principal component analysis shows the percent of class Ⅲ water is higher than other classes. The result of voronoi area weighting factor method shows the percent of IV class is higher than other classes. CODMn is the main factor that influences the method of singal factor evaluation and reduces the grade of water quality overall. The effect of single factor is reduced by principal component analysis, and the analysis on water quality is more accurate. The voronoi area weighing factor method reduces the effect of single factor and extends the content, can make a comprehensive evaluation on water quality.

Water quality characteristics and assessment of Yongding New River by improved comprehensive water quality identification index based on game theory

The Yongding New River is essential for the water supplies of Tianjin.To date,there is no comprehensive report that assesses the year-round water quality of the Yongding New River Main stream.Moreover,little attention has been given to determining a combined weight for improving the traditional comprehensive water quality identification index(ICWQII)by the game theory.Seven water quality parameters were investigated monthly along the main stream of the Yongding New River from May 2018 to April 2019.Organic contaminants and nitrogen pollution were mainly caused by point sources pollution,and the total phosphorus mainly by non-point source pollution.Dramatic spatio-temporal variations of water quality parameters were jointly caused by different pollutant sources and hydrometeorological factors.In terms of this study,an improved comprehensive water quality identification index(ICWQII)based on entropy weight or variation coefficient and traditional CWQII underestimated the water qualities,and an ICWQII based on the superstandard multiple method overvalued the assessments.By contrast,water qualities assessments done with an ICWQII based on the game theory matched perfectly with the practical situation.The ICWQII based on game theory proposed in this study takes into account not only the degree of disorder and variation of water quality data,but also the influence of standard-exceeded pollution indicators,whose results are relatively reasonable.All findings and the ICWQII based on game theory can provide scientific support for decisions related to the water environment management of the Yongding New River and other waters.

The Influence of Alluvial Mining on the Morphology and Ecological Health of the Jhimruk River in Pyuthan, Nepal

Historically, alluvial rivers have been a desirable source of sediment for various industrial purposes. However, the demand for sand is rapidly increasing, leading to environmental concerns associated with its extraction. The extraction of sediment from riverbeds has both visible and invisible effects. This research aims to investigate the dynamics of the Jhimruk River’s morphology and its impacts by evaluating the river’s quality and studying its changing morphology. To assess morphological changes, satellite images from different years were compared using Geographic Information System (GIS). Physical assessments were conducted by calculating a Habitat score based on various parameters. Water quality assessments involved measuring factors such as pH, temperature, nitrate levels, and alkalinity. A water quality map of the river was generated using color coding to indicate different conditions. The Habitat score demonstrated variations in the data collected from all sites, with factors such as instream cover, bottom substrate stability, riparian vegetation, and aesthetic of the river stretch playing crucial roles in influencing the total score. The Water Quality Index value for the disturbed site indicated moderate pollution, falling under class II. Aquatic macroinvertebrates displayed natural responses to increasing levels of stressors across their life stages, as observed through the analysis of the GRS-BIOS/ASPT index. With the exception of the disturbed site, all other sites were classified under water quality class II, while the disturbed site belonged to class III, indicating a moderate to critically polluted state for most of the Jhimruk River. Furthermore, an increase of 180.87 meters in the river width at the disturbed site provided evidence of morphological changes occurring over the specified period. Mining activities were identified as a significant contributor to the alteration in river morphology.

四川省感染性疾病分子生物学重点实验室

四川省感染性疾病分子生物学重点实验室四川省教委高教处四川省感染性疾病分子生物学重点实验室依托于华西医科大学，研究领域涉及分子生物学、细胞生物学、免疫学、临床药理学、抗生素学和临床医学，以微生物感染、抗生素化疗为主要研究方向。实验室总面积约５００平方米...

基于萤火虫算法的BP神经网络的水质评价

Assessment of water quality by firefly algorithm based on BP neural network model(FA-BP model)is built.In this model,the evaluation index function is constructed by BP Artificial Neural Network Algorithm(BP model),and Firefly Algorithm(FA model)is introduced to optimize weight values and thresholds to find the optimal solution.Fuzzy Comprehensive Evaluation method,Grey Incidence Analysis Algorithm and FA-BP model will be applied to evaluate the water quality of the five main rivers in Lianyungang City including Longwei,Yudai,Dapu,Paidan,and Dongyan River.The results show that the Fuzzy Comprehensive Evaluation method is difficult to use for slight pollution rivers with several slightly over standard indexes.It will be easy to ignore the impact of extreme indexes by Grey Incidence Analysis Algorithm.FA-BP model solves the shortcomings of the two methods.The evaluation results provide an important reference for the formulation of reasonable measures.It is a relatively comprehensive evaluation method and has a good application prospect in water quality evaluation.

Towards real-time detection of wastewater in surface waters using fluorescence spectroscopy

The presence of municipal wastewater at the intake of a major drinking water treatment facility located on Lake Ontario was examined using fluorescence data collected during a period of continuous monitoring.In addition,controlled mixing of lake water and wastewater sampled from a local treatment facility were conducted using a bench-scale fluorescence system to quantify observed changes in natural organic matter.Multivariate linear regression was applied to components derived from parallel factors analysis.The resulting mean absolute error for predicted wastewater level was 0.22%(V/V,wastewater/lake water),indicating that wastewater detection at below 1.0%(V/V)was possible.Analyses of sucralose,a wastewater indicator,were conducted for treated wastewater as well as surface water collected at two intake locations on Lake Ontario.Results suggested minimal wastewater contribution at the drinking water intake.A wastewater detection model using a moving baseline was developed and applied to continuous fluorescence data collected at one of the drinking water intakes,which agreed well with sucralose results.Furthermore,the simulated addition of 1.0%(V/V)of wastewater/wastewater was detectable in 89%of samples analyzed,demonstrating the utility of fluorescence-based wastewater monitoring.