Water Quality Index Research Articles

Biodiversity and distribution of zoobenthos in the ecological water replenishment area of the Yellow River estuary coastal wetland revealed by eDNA metabarcoding.

The coastal wetland of the Yellow River Estuary, one of China's largest wetlands, is essential for biodiversity conservation and ecosystem services. Ecological water replenishment, a typical wetland restoration measure in the Yellow River Delta, has significantly impacted the habitat of zoobenthos, which are critical indicators of ecosystem health and water quality. However, the community characteristics of zoobenthos in this coastal wetland are poorly understood. This study utilized eDNA metabarcoding to assess the diversity and community structure of zoobenthos in the ecological water replenishment area of Yellow River Estuary Coastal Wetland. Zoobenthos from 174 families were identified, with 307 species recognized at the generic level, significantly more than those identified through traditional morpho-taxonomic approaches. Salinity emerged as a crucial factor in shaping these ecosystems. Contrary to expectations, in this study, brackish water exhibited the lowest species richness compared to freshwater and seawater, which may be attributed to local environmental stressors and fluctuating salinity conditions in the Yellow River Estuary. Environmental factors such as salinity, organic matter, and nutrient elements significantly influence the composition and distribution of zoobenthos. Specifically, cations, particularly Mg2⁺ and Ca2⁺, have a more substantial impact on zoobenthos than anions. Our results provide crucial information on zoobenthic biodiversity within ecological water replenishment areas, offering insights into the ecological dynamics and environmental factors shaping zoobenthos communities under ecological management.

Spatial and seasonal variations in physico-chemical parameters and the water quality index at the Okhuaihe River in Ikpe Community, Edo State, Nigeria

The scarcity of clean water in rural Nigerian communities leads to dependence on streams and rivers which are often polluted by domestic and industrial activities distorting the quality of water. Freshwater ecosystems, which are important for global biodiversity, are constantly burdened with threats from environmental changes as well as human misuse. This study was aimed at investigating the spatial and temporal variations of physico-chemical parameters and the water quality index (WQI) of the Okhuaihe River in Ikpe, Edo state, Nigeria, used for different domestic activities. The study assessed parameters like air and water temperature, pH, electrical conductivity, flow rate, total dissolved solids, phosphate, chloride, iron, zinc, and manganese at four stations over a six-month period. Samples such as air and water temperature and pH were collected and measured in situ, while others were collected using polyethylene bottles and a 250 ml amber bottle for biochemical oxygen demand (BOD5). Results indicated that while some physico-chemical parameters like the width, the flow rate, and phosphate showed considerable differences, most did not differ significantly. Temporally, there were significant seasonal variations in air temperature, electrical conductivity, total dissolved solids, chloride, iron, zinc, and manganese. The WQI calculations showed that the water quality at all stations was within safe limits for human consumption and supported aquatic life. Despite some fluctuations due to seasonal changes and anthropogenic activities, the overall quality remained suitable for domestic use. This underscores the importance of constant monitoring and management of water resources to allay pollution and ensure sustainable water supply in rural communities.

Physico-Chemical and Microbiological Quality of the Surface Water of the Nostoc Commune of the Andean Communities of Huancavelica, Peru

Objective: The purpose was to evaluate the physicochemical and microbiological quality of surface water from the Nostoc commune of Andean communities in Huancavelica-Peru, and to compare its variation in relation to its distribution and environmental conditions. Theoretical Framework: Surface water quality depends on anthropogenic factors. The physico-chemical and microbiological surface water quality indicators of the Nostoc commune are important for environmental monitoring, biomass production and social economic livelihoods. Method: Samples of surface water from streams and ponds were considered as biological material. The physicochemical and microbiological analyses were determined according to the protocol and recommendations established in the Standard Methods for the Examination of Wastewater of APHA (2012) and ECA (2017). Results and Discussion: The results revealed that the physicochemical and microbiological parameters of surface waters of streams and ponds inhabited by Nostoc commune meet the guidelines established by ECA and APHA, with variations to their geographical distribution and environmental conditions. Meteorologically, Nostoc commune is common at altitudes between 4240 and 5877 masl, with temperatures of 4-14°C and relative humidity of 20-60% varying between January and April. Research Implications: The study shows the surface waters of the Nostoc commune to be unsuitable for agricultural and human use. It is crucial for public and environmental health as a balancer of surface water quality. Originality: It offers unprecedented contributions to the literature on the quality of the surface water of the Nostoc commune habitat. The relevance and value of this algae as a viable source of water utilization for agricultural and public health purposes is evident.

Entropy-weighted water quality index assessment of groundwater in Ibadan metropolis, Southwestern Nigeria

An entropy-weighted water quality index (EWQI) was used in this study to evaluate the quality of groundwater in parts of the Ibadan metropolis, Nigeria. Seventy-five groundwater samples were collected and analysed for pH, electrical conductivity, total hardness, alkalinity, turbidity, total dissolved solids, cations (Na+, K+, Ca2+, Mg2+), anions (HCO3−, Cl−, SO42−, NO3−, F−), Fe and Total Heterotrophic Bacteria Content (THBC). The pH of the groundwater in the study area ranges from neutral to slightly alkaline. Based on the average concentrations, the abundance of anions is in the order as follows: Cl− > HCO3− > SO42− > NO3− > F−, while that of cations is Na+ > K+ > Ca2+ > Mg2+. The groundwater type was predominantly of mixed and Na-Cl types, likely controlled by multiple processes, such as water–rock interaction and mineral weathering. Anthropogenic activities, including improper waste disposal and sewage contamination, were also identified as significant contributors to groundwater quality degradation. The prevalent bacteria in this study are Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The average EWQI value was 32.8, with values ranging from 2.2 to 143.6. Most of the groundwater in the research area, according to the EWQI, has good to excellent quality for drinking, while only 20% of the samples were medium to low quality, necessitating minimum treatment.

Geospatial mapping and entropy-based analysis for groundwater evaluation with estimation of potential health risks due to nitrate and fluoride exposure.

Groundwater is a vital source of freshwater, but its quality is often compromised by various physiochemical factors. In the Mid-Gangetic Plains, there is a concerning escalation in the degradation of groundwater quality due to anthropogenic interventions. However, there remains a paucity of comprehensive knowledge concerning groundwater quality and the associated health hazards it poses. In response to this gap, the current study focuses on Nalanda district (Bihar), where 78 groundwater samples were collected across district in the month of May 2022 and their various water quality parameters were quantified as per standard methods. The adequacy of groundwater for human use was assessed using an entropy-based water quality index (EWQI), which also evaluated the potential human health risk stemming from nitrate and fluoride contamination. Furthermore, an empirical Bayesian kriging (EBK) driven geostatistical approach was utilized to predict water quality parameters at ungauged sites. The analysis of results disclosed that the ionic dominance in groundwater followed the sequence as cations Ca2+ > Mg2+, and anions HCO3- > SO42- > Cl- > NO3- > F- > PO43-. The concentration of NO3- and F- exceeded the permissible BIS levels by 11.5% and 6.5% of the samples respectively. The analysis of EBK models suggested K-Bessel as the best-fit model for pH, Mg2+, TH, F-, NO3-, and SO42- spatial interpolation while exponential EBK model for EC, Cl-, and PO43- and whittle EBK model for TDS, Ca2+, and HCO3- spatial interpolation. Spearman's correlation analysis revealed that elevated TDS and EC levels, coupled with correlations between NO3-, SO42-, and Cl-, suggest anthropogenic influences. The EWQI of the groundwater samples ranged from 36.28 to 180.80. The analysis of EWQI values revealed predominantly fair to good groundwater quality across the study area, suitable for drinking purposes. The hazard quotients for NO3- and F- indicate that non-carcinogenic health risks are more significant with nitrate pollution. The combined health impact was assessed using total hazard index (HI), ranging from 0.20 to 3.29 for children, 0.19 to 3.05 for males, and 0.17 to 2.70 for females. The cumulative probability distribution revealed total hazard index (HI) > 1 in 41.56%, 34.62%, and 28.21% of samples for children, males, and females. The HI analysis indicated a substantially higher risk for children compared to adults within the study area. This study offers a novel combination of entropy-based water quality assessment and geostatistical EBK modeling to evaluate groundwater quality and health risks in ungauged areas. The findings provide valuable insights for improved groundwater management and health risk mitigation.

Using Two Water Quality Indices for Evaluating the Health and Management of a Tropical Lake

With increasing pressure on freshwater resources in developing countries due to population growth, further research and potential interventions are crucial. Lake Tana, located in the headwaters of the Blue Nile, serves as a critical example of these precious freshwater resources. This study evaluated the water quality of Lake Tana for both ecological health and drinking purposes using the Arithmetic Weighted Water Quality Index (AW WQI) and the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI). Samples were collected from 20 lake sampling stations four times between July 2018 and June 2019 to calculate the two water quality indices using ten measured parameters. The average annual AW WQI ranged from good to very poor for ecological health and very poor to unsuitable for drinking water. The CCME WQI categorized Lake Tana’s water quality as poor to fair for both uses. According to the water quality indices, the water quality was most impacted by turbidity, dissolved oxygen, ammonium, and phosphorus. However, except for ammonium, these factors were immaterial for lake management because the lake was nitrogen-limited, and the turbidity resulted from sediment stirred up by waves from the lake bottom, which cannot be managed easily. Dissolved oxygen is related to turbidity. Moreover, the WQIs did not identify two pesticides in the lake that negatively affected the fish. Thus, WQI indices may document water quality changes over time. Therefore, in addition to a favorable economic and political climate, improving lake water management requires insights from experts, the scientific literature, and possibly additional monitoring in addition to what is provided by the WQIS.

Assessing groundwater quality in northern Algeria using geochemical and index approaches

This study aims to enhance understanding of the hydrogeochemical behavior of the aquifer by utilizing a water quality index in conjunction with hydrogeochemical analysis. The focus is on identifying the factors that control its chemical composition and influence its suitability for domestic use. Water samples were collected from twenty boreholes and analyzed for major ions, pH, and electrical conductivity during the dry and wet seasons. During the wet season, the water quality index indicated generally good chemical quality, with an average score of 96.12. This was categorized as Excellent (5%), Good (55%), and Poor (40%). In contrast, the dry season showed a slight deterioration in water quality, with an average score of 102.57, reflecting a distribution of Excellent (10%), Good (35%), and Poor (55%). Boreholes located in the western and central parts of the aquifer exhibited better chemical quality compared to those in the eastern part, which are considered unsuitable for human consumption due to their poor quality. The mineralization process is primarily attributed to the dissolution of dolomitic and evaporitic formations, resulting in various chemical facies. The dominant facies identified were calcium and magnesium bicarbonate (85%), followed by sodium bicarbonate (7.5%), calcium sulfate (5%), and sodium chloride (2.5%). This study underscores the critical need for sustainable management practices to protect groundwater quality in the Mitidja plain amid ongoing environmental challenges. Addressing these issues is essential for ensuring safe drinking water availability for local communities.

Diatoms as an Indicator of Water Quality in the Kuils River, Western Cape, South Africa

Rivers are crucial hydrological cycle components, supporting ecosystems and human activities. Managing and protecting river water quality is essential. Diatoms, microscopic algae, are widespread and sensitive to changes in water quality, making them effective bioindicators. This study focused on the Kuils River in the Western Cape, South Africa, where diatom sampling was conducted at four sites. Their communities are affected by different physicochemical parameters, such as changes in pH, salinisation, eutrophication, and organic enrichment. A total of 98 diatom species were identified. The Omnidia software was used to calculate the Generic Diatom Index, Specific Pollution Index, and Trophic Diatom Index. Historical physicochemical data such as pH, chemical oxygen demand, and phosphorus were obtained from the Department of Water and Sanitation between 2019 and 2021 and were used to provide a reference for comparing diatoms. The results showed clear signs of pollution, as shifts in diatom species composition were observed. Pollution-tolerant species such as the Nitzschia palea (Kützing) W Smith 1856, Navicula viridula (Kützing) Ehrenberg 1838, Eunotia bilunaris (Ehrenberg) Schaarschmidt 1880, and Ulnaria ulna (Nitzsch) Compère 2001 dominated, while less pollution-tolerant species like Gomphonema parvulum f.saprophilum Lange-Bertalot and E. Reichardt 1993 and Stephanocylus meneghinianus (Kutzing) Kulikovskiy, Genkal, and Kociolek 2022 were less abundant. Both diatom indices and physicochemical data indicated poor water quality in the Kuils River. The study concludes that diatoms are a valuable tool for biomonitoring river water quality and recommends their use alongside traditional physicochemical methods for future assessments of river systems.

Comparative analysis of water quality index based on seasonal differences in the upstream Citarum watershed

ABSTRACT The Upstream Citarum Watershed is the largest watershed in West Java Province that supports the activities and livelihoods of its surrounding communities. Thus, continuous monitoring of the Citarum River's water quality is essential, with the water quality index (WQI) as an effective tool for assessing its status. Various methods can be used, such as the National Sanitation Foundation WQI (NSF-WQI), the Prati index, and the Dinius index. This study aims to compare these three methods based on secondary data in the form of water quality data from the Regional Environmental Management Agency of West Java Province (2013–2022) collected at four monitoring points, namely, Wangisagara, Koyod, the area after the wastewater treatment plant (WWTP) at Cisirung, and Nanjung. Additionally, primary data from sampling conducted at the same monitoring points were analyzed. The data obtained were categorized based on wet–dry months, wet–dry years, monitoring points, and monitoring years. Based on this study, the water quality status of the Upper Citarum River Basin was obtained in the form of 'Good' and 'Moderate' by the NSF-WQI method; 'Excellent', 'Acceptable', 'Slightly Polluted', and 'Polluted' by the Prati index method; and 'Excellent', 'Good', 'Moderate', 'Bad', and 'Very Bad' by the Dinius index method.

Groundwater quality assessment for drinking and irrigation: a case study in the Cauvery River Basin (CRB) of Tiruchirappalli District, Tamil Nadu, India

ABSTRACT The long-term impacts of human activities on groundwater quality in the Cauvery River Basin are not well understood, particularly the combined effects of urbanization, industrialization, and agriculture. Seasonal factors, such as precipitation and water-table fluctuations, also influence groundwater chemistry, affecting its suitability for drinking and irrigation. This research aims to assess the hydrochemical characteristics of groundwater and evaluate its long-term suitability for these purposes, considering both natural and anthropogenic factors. A total of 56 groundwater samples were collected and analyzed for various physicochemical and biochemical parameters. The results showed that the most prevalent ions are bicarbonate (27.3%), chloride (24.1%), and calcium (16.6%), followed by sulfate, magnesium, sodium, and others. The Piper and Gibbs plots indicated that most groundwater samples belong to the mixed calcium chloride facies, and rock–water interaction is the dominant natural mechanism, with some anthropogenic influences, respectively. The GIS-based drinking water quality index (DWQI) map showed that 66% of the samples were of excellent to good quality for drinking without treatment, while the remaining samples were of moderate quality and nearly unsuitable for drinking, requiring further treatment. However, most of the groundwater samples were suitable for irrigation based on irrigation water quality indices.

Management of groundwater resources in the Tolga region (south-east Algeria)

This study attempted to assess and map the quality of Tolga's groundwater in order to determine its suitability for human consumption and agricultural use. The results of analyses of the physicochemical parameters of the water samples were compared with WHO potability standards and standard agricultural water quality indices, namely sodium adsorption ratio SAR ,Soluble sodium percentage Na% , Magnesium risk MH , Kelly ratio KR and permeability index PI. According to the results analysed, most of the physicochemical parameters are above WHO tolerance limits and within the limits of empirical water quality indices for agricultural use. In our study, the graphical maps obtained by kriging are fitted with theoretical variogram models that best approximate the point cloud. The suitability of these models for our sample is verified by cross-validation results. The graphical representation shows high concentrations of conductivity, salinity, calcium, magnesium, sodium, bicarbonate and chloride, which are located in the Eastern part of the region, and increase progressively from northwest to east. These waters are highly charged with salts and have maximum conductivity values.

Macrozoobenthos community structure as a bioindicator of water quality in the Banjaran River, Banyumas

The Banjaran River is one of the rivers in the Banyumas Regency. This research aims to produce information related to macrozoobenthic community structure as a bioindicator of water quality in the Banjaran River and to produce information related to water quality in the Banjaran River for macrozoobenthic life. The research was conducted in September 2022 – February 2023 on the Banjaran River, Banyumas. This research uses a survey method, sampling was carried out 3 times in September-November 2022. The sampling method was purposive random sampling, namely the river was divided into 3 stations based on certain criteria. The results of this research obtained 15 species and were divided into 11 families, namely Perlidae, Psychomyiidae, Thiaridae, Lumbricidae, Naididae, Gecarcinucidae, Palaemonidae, Elmidae, Hydropsychidae, Atyidae, and Chironomidae in the Banjaran River. The highest abundance of individuals was at station two, namely 3156 individuals/m2. The dominant species is Melanoides tuberculata with an abundance of 1852 individuals/m2 at station two. The dominance index values at the three stations ranged from 0.1864 to 0.2886, which is relatively low. The water quality in the Banjaran River for macrozoobenthic life is still quite good based on the results of measuring environmental parameters which consist of physical parameters, namely water temperature and current speed.Keywords: Banjaran River, Macrozoobenthos Community, Water Quality Indicators

Assessing the suitability of water for irrigation purposes using irrigation water quality indices in the Irob catchment, Tigray, Northern Ethiopia

ABSTRACT Irrigation alleviates poverty in arid and semi-arid regions, such as Ethiopia, necessitating a water suitability assessment. This study evaluates irrigation water quality in the Irob catchment, Northern Ethiopia. It differs by using combined parameters of the irrigation water quality index (IWQI) for comprehensive assessment beyond standard comparisons. Eighteen water samples were collected and analyzed using ultraviolet spectrometry, titration, and atomic absorption spectrometry. The evaluation included parameters such as salinity, total dissolved solids (TDS), total hardness (TH), sodium adsorption ratio, sodium percentage, residual sodium carbonate, permeability index, magnesium ratio, Kelly's index, potential salinity, and the IWQI. The findings revealed that 22.2, 38.9, 88.8, 66.7, 83.3, 66.7, 100, 72.2, and 55.6% of samples exceeded recommended standards for electrical conductivity, TDS, TH, permeability index, manganese, cobalt, copper, cadmium, and nickel, respectively. Most water quality parameters meet standards, but improved irrigation management is crucial to reduce risks. The IWQI indicates that 22.2% of water samples have minor restrictions, while 77.8% have no restrictions. This method provides key insights for evaluating irrigation water quality in similar hydrogeological and environmental conditions, particularly in semi-arid and arid regions. The findings enhance the understanding of sustainable water quality, supporting local authorities in developing resilient irrigation strategies for regional agricultural sustainability.

Tracking ground water quality changes in Wadi El-Assiuti, Assiut, Egypt

ABSTRACT Wadi El-Assiuti, a valley in Assiut governorate, Egypt, is the only irrigation source in this area. This study provides a comprehensive analysis of the groundwater quality parameters in this valley. Thus, the physiochemical quality parameters, such as sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), sodium percentage (Na%), soluble sodium percentage (SSP), Kelly Ratio (KR), potential salinity (PS), water quality index (WQI), and irrigation water quality index (IWQI), were examined. The results revealed that groundwater, in general, was highly saline. Each of the physical and chemical parameters started with high values, but due to continuing groundwater use for years, they decreased and then increased again in 2019. The water quality parameters behave the same way as the physical and chemical parameters such as SAR but do not exceed 15.92, MAR; raised more than 50% in both periods, Na%; from 51.85 to 54.74% (with a maximum value of 65.46% in 2013) and from 54.74 to 80.52% in the period 2012–2014 and 2016–2020, respectively, SSP; rose more than 60% in both periods but reached 80.02% in 2020, KR; they rose more than 1 in both periods but reached 4 in 2020, PS; raised more than 3 meq/L in both periods but also reached 50.45 meq/L in 2020, WQI; rose more than 100 in both periods, and IWQI; rising more than 100.

Application of multivariate statistical techniques in the assessment of long-term surface water quality in Dong Thap Province, Vietnam.

This study assessed the surface water quality in Dong Thap province during 2013-2023 using multivariate statistical techniques. Water quality index (WQI), Pearson correlation, principal component analysis (PCA), and cluster analysis (CA) were determined based on monitoring data for parameters. The findings showed that only some water samples had pH values below the permissible standard, while 95.5% of samples exceeded the standard of Escherichia coli in surface water. In some years, 100% samples having BOD5, TSS, NH4+, and E. coli exceeded the permissible limits. The PCA identified four, five, and seven major potential sources during 2013-2015, 2016-2020, and 2021-2023, respectively, explaining 75.9%, 63.0%, and 63.0% of variation in the corresponding duration times. For heavy metals, the number of water samples containing As, Cu, and Pb exceeding the water permissible limits were 15.5%, 21.4%, and 2.8% samples in 2021, respectively, but no heavy metal was above standard in 2022 and 2023. The evaluation of average water quality based on WQI showed that 79.31% and 76.19% of the sample sites were classified to be average during 2016-2020 and 2021-2023, respectively, and others were bad water quality. However, the water quality showed an improving trend with 70% of monitoring positions considered as good water quality in 2023. The results showed that anthropogenic activities and hydrological regime were the main source of pollution. This study provides guidance to policymakers in developing water management strategies to have proper actions to prevent water pollution.

Water Quality Assessment using Selected Macroinvertebrate Based Indices and Water Quality Index of Sungai Air Hitam Selangor

A study was conducted from July to December 2022 at Sungai Air Hitam, a small tributary of the Selangor River located within the Tanjung Karang Sub-basin in Malaysia (coordinates: 3° 24' 27" N, 101° 25' 54" E to 3° 28' 14" N, 101° 26' 59" E). This confluence is situated near three major downstream water treatment plants. The study assessed six water quality parameters—pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia (NH3), and suspended solids (SS)—to calculate the Water Quality Index (WQI). Macroinvertebrates were sampled simultaneously using the dipping net method to obtain biotic indices for further evaluation of water quality. The results indicated that the WQI classified Sungai Air Hitam as Class III, with scores ranging from 56.9 to 64.6, suggesting the river is suitable for water supply and fisheries. However, the Biological Monitoring Working Party (BMWP) index categorized the water quality as poor, with scores between 30 and 42. Similarly, the Average Score Per Taxon (ASPT) ranged from 3.25 to 5.25, indicating pollution or environmental impact, while the Family Biotic Index (FBI) further classified the river as having poor to very poor water quality, with scores between 6.57 and 8.11. Overall, the study suggests that Sungai Air Hitam has experienced some degree of ecological degradation. These findings emphasize the need for continuous monitoring and remediation efforts to preserve and restore water quality.

Identification of the Driving Factors to Algal Biomass in Lake Dianchi: Implications for Eutrophication Control

Accurate analysis of spatiotemporal variations in algal biomass and their underlying causes is crucial for controlling algal blooms and enhancing aquatic ecological quality. The present study, spanning 2011 to 2020, was conducted across 10 sites in Lake Dianchi, where peak algal biomass levels occur from May to September, with higher concentrations in the lake’s northern zones compared to other areas. Employing Spearman’s correlation analysis, generalized additive models (GAMs), and random forest (RF) techniques, the relationships between algal biomass and water quality indicators were investigated. Spearman’s correlation analysis revealed a positive relationship between chlorophyll a (Chla) and total phosphorus (TP) across various spatial scales. RF analysis identified TP as the most influential factor on a lake-wide scale; while in localized RF models, organic pollution-related indicators (COD, CODMn, and BOD5) and TP consistently emerged as the primary predictors of Chla at most sites. GAM results indicated spatially variable and nonlinear responses of algal biomass to predictors, reinforcing TP’s significance lake-wide and at many localized scales. This comprehensive analytical approach provides valuable insights into the role of water quality factors and nonlinear dynamics, thereby advancing our understanding of the relationships between algal biomass and environmental conditions. These findings are pivotal for the development of scientifically informed strategies for lake management and conservation.

ANALISIS PERSEPSI, SIKAP, DAN PERILAKU MASYARAKAT TERHADAP PENCEMARAN AIR DI PELABUHAN KOTA PASURUAN

The Gembong River is a river included in the longest watershed in Pasuruan City with a length of 7.5 km. The estuary of the Gembong River is relatively wide, so it is used as a traditional port. However, the river flow in Pasuruan does not meet the quality standards for class two due to the large number of pollutants from the household and industrial sectors. Based on the results of observations that have been carried out in the Gembong River estuary area or the Pasuruan City port area, it can be seen that there is still some waste, ranging from household waste and plastic waste from snack wrappers. The method used in this study was descriptive qualitative. Data were collected through observation and interviews with 36 respondents. The instruments used in collecting data were questionnaires and interview guidelines. The sampling technique used was purposive sampling. Primary data in the form of analysis of data results regarding aspects of knowledge, attitudes, and actions of the community towards efforts to maintain river sustainability. Secondary data in the form of water quality index and its parameters in the Gembong River estuary area. The results of this study showed that based on the results of the water quality test analysis, it can be seen that the Gembong River is included in the river with lightly polluted criteria. awareness and behavior of the community around the estuary of the Gembong River or the port of Pasuruan City is quite good. However, there is still a need for optimization of the government's work programs in conducting socialization and involving the community in the prevention or control program for river pollution, so that it is hoped that the community can actively participate in protecting the environment.

A Groundwater Quality Assessment Model for Water Quality Index: Combining Principal Component Analysis, Entropy Weight Method, and Coefficient of Variation Method for Dimensionality Reduction and Weight Optimization, and Its Application.

Groundwater underpins water supply for most of the world's regions, yet its sustainable utilization has been markedly compromised by inappropriate exploitation and a multitude of pollution sources. Water quality evaluation has emerged as an essential strategy to guarantee the optimized utilization and vigilant conservation of water resources. In this study, principal component analysis (PCA), entropy weight method (EWM), coefficient of variation method (CVM), and Water Quality Index (WQI) were used to construct an integrated WQI groundwater quality assessment model that integrates PCA-CVM-EWM for dimensionality reduction and weight optimization. Taking a village in Shandong Province, China, as an example, PCA identified seven evaluation indicators. The CVM-EWM were coupled to calculate comprehensive weights through the principle of minimum information entropy, followed by a comprehensive assessment of groundwater quality based on WQI values. The results indicated that Class III groundwater predominated in the study area, accounting for 74%, with localized pollution present. The hydrochemical type of the groundwater was primarily SO4·HCO3-Ca, significantly influenced by human activities. The coefficients of variation for Fe, Mn, and NH4-N all exceeded 1. Compared to other methods, the optimized WQI model demonstrated superior performance in the selection of evaluative indicators, weight distribution, and comprehensive water quality assessment, showing a distinct advantage for water quality data with numerous hydrochemical indicators and substantial coefficients of variation. The findings provided a scientific reference for diagnosing groundwater quality issues and formulating preventive and control measures. PRACTITIONER POINTS: A comprehensive water quality index evaluation model was constructed. Optimized steps for selecting indicators and assigning weights for the water quality index model. Selection of evaluation indicators based on indicator correlation analysis. The variability of hydrochemical data is considered.

Relationships between the spectral characteristics of dissolved organic matter and river ecological health indicators: A case study in the Shichuan River basin on a typical semi-arid and semi-humid region of China

The spectral characteristics of dissolved organic matter (DOM) in rivers are considered as potential indicators of river health status. In this study, relationships between DOM spectral properties and river ecological health indicators in Shichuan River, such as total nitrogen (TN), total phosphorus (TP), chlorophyll-a (Chl-a) content, diversity of macrobenthic invertebrates, water quality index (WQI), and trophic level index (TLI), etc., were investigated. According to the WQI values, the water quality of the Ju River and Taoqupo Reservoir was generally better than that of other river sections, while the Qinghe and the mainstream sections performed the worst. The fluorescence index (FI) and WQI reflects that the mainstream of the Shichuan River bears a significant amount of sewage input. Besides, FI showed a significant positive correlation with nitrate nitrogen (NO3−-N), TN, TP, Chl-a, and TLI, while a significant negative correlation with WQI. The specific ultraviolet absorbance of 254 nm (SUVA254) had a positive correlation with TLI. Indeed, the UVC humic-like component (C1) showed a significant positive correlation with the macroinvertebrates diversity. The humification index (HIX) was significantly negatively correlated with sediment pollution index. Our results suggested that DOM fluorescence characteristics had the potential to be developed as a convenient method for assessing aquatic ecological health.