Epilithic diatoms as indicators of water quality in Upano River, Ecuador

In this work, a hydrodynamic and water quality model was developed for Lake Nubia based on a two-dimensional, laterally averaged and finite difference hydrodynamic and water quality code, CE-QUAL-W2. The model was calibrated and verified using data which were measured in the years of 2006 and 2007 during low flood periods, respectively. Measurements during the flood season are not available. The results of the presented model show a good agreement with the observed hydrodynamic and water quality records.
\nTwo water quality indices (WQIs), NSF WQI and CCME WQI, have been developed to assess the state of water quality in the investigated case study, Lake Nubia, during the first low flood period of January 2006. The CCME WQI has been modified to use the Egyptian standards (objectives) of raw water. Moreover, another two trophic status indices, Carlson TSI and LAWA TI, have been developed to evaluate the trophic status of Lake Nubia during the same period of January 2006. Results of the previously developed hydrodynamic and water quality model for Lake Nubia were used to validate the model. According to the developed water quality indices results, Lake Nubia has a good water quality state during the low flood period. The modified CCME WQI (based on measured data) indicates that the Lake Nubia water quality state is excellent according to the Egyptian standards of water quality for surface waterways. Results of the applied trophic status indices show that the Lake Nubia trophic status is eutrophic during the studied period. 
\nThe effect of the global climate change on the hydrodynamic and water quality characteristics of Lake Nubia was conducted for the 21st century. To do that, the outputs of eleven global climate models for two global emissions scenarios combined with hydrological modeling were used. A theoretical process algorithm has been simplified, further developed and calibrated to modify the initial conditions of dissolved oxygen due to the global climate change effects. A sensitivity analysis has been conducted by using each of the predicted air temperature and inflow data separately in the model in order to investigate its effect on the characteristics of the hydrodynamic and water quality. Three hydrodynamic characteristics of the reservoir were investigated with respect to the climate change: water surface levels, evaporation water losses and thermal structure. In addition, eight water quality characteristics of the reservoir were investigated with respect to the climate change: dissolved oxygen, chlorophyll-a, ortho-phosphate, nitrate-nitrite, ammonium, total dissolved solids, total suspended solids and potential of hydrogen (pH). Moreover, the climate change effects on the water quality and trophic status indices have been studied. The results of the climate change study show partially significant impacts on the examined hydrodynamic and water quality characteristics, while the water quality and trophic status indices are slightly affected by the climate change scenarios.

This study, carried out seasonally between October-2019 and July-2020, aimed to determine the water quality using some water and epilithic diatom indices of the Köprüçay River. It is located in the south of Türkiye and used for tourism, irrigation and drinking water. Ammonium nitrogen (NH4–N), nitrate nitrogen (NO3–N), sulfate (SO4 −2), bicarbonate (HCO3 −), orthophosphate (PO4–P), chloride (Cl−), biochemical oxygen demand (BOD5), temperature (°C), dissolved oxygen, pH, and electrical conductivity were measured. Water quality was determined according to the Surface Water Quality Regulation (SWQR) and Water Quality Index (WQI). The water quality classes of the stream, based on epilithic diatom assemblages, were determined using the Generic Diatom Index (GDI), Saprobi Index (SI), Trophic Index (TI), Swiss Diatom Index (DI-CH), and Trophic Diatom Index (TDI). According to SWQR, the average values of the parameters at all sites were generally in the class I or II (high quality or lightly polluted water). WQI, was calculated based on seasonal and site and all results were determined as “excellent water”. 117 taxa belonging to 51 genera of epilithic diatoms were observed in the Köprüçay River. According to epilithic diatoms, generally all sites were in the range of very slightly polluted or partially polluted (I and II) water quality classes.

The use of diatoms as bio-indicators of water quality is common in temperate regions worldwide. However, less attention has been accorded to sub-tropical regions, particularly in Australia. This study assessed the value of diatom communities to infer water quality in a sub-tropical riverine system. Epilithic diatom and water samples were collected monthly from an east Australian river. Principal components analysis showed that the Lower Catchment sites were more strongly influenced by the measured environmental variables differentiating them from the Upper Catchment sites. Canonical Correspondence Analysis showed electrical conductivity and total phosphorus strongly influenced the diatom community distribution. The study revealed diatom species that are robust bio-indicators of water quality in this sub-tropical catchment. Cocconeis placentula, C. placentula var lineata, Gomphonema spec 2 and Tabellaria flocculosa were identified as indicators of moderate water quality. Bacillaria paradoxa, Navicula cryptocephala, Navicula mutica var mutica and Achnanthes fogedii were identified as indicators of poor water quality. This study identified that diatoms are effective indicators of water quality. Further research is required to develop a diatom biological index applicable to sub-tropical east Australian river systems to improve the effectiveness of environmental monitoring and sustainable river management.

Issue By 2025, half of the world's population will be living in water-stressed areas. Managing water quality and quantity is a worldwide concern that will require investing in WATER Centers and monitoring systems to improve the safety of drinking water and contribute to water conservation worldwide. Without reliable water policy climate change will threaten human survival. Problem There is no single measure that can describe overall water quality for any one body of water, let alone at a global level. Seven assessment methods used to measure water quality either on a national or global level, were reviewed and indexed. This index was examined and compared by objective, use, distribution and global location. Water centers need to review community water process, outcomes and outputs and also provide user populations with a Water Quality and Water Quantity Index (WQQI). Results United Nations Environment Programme UNEP research has revealed that “although there is no globally accepted composite index of water quality, some countries and regions have used, or are using, aggregated water quality data in the development of water quality indices.” 'Most water quality indices rely on normalizing, or standardizing data by parameter according to expected concentrations and some interpretation of 'good' versus 'bad' concentrations”. Lessons The survival of the human population requires policy changes regarding water management. The feedback humans need to survive can best be described as a Water Quality and Quantity Index (WQQI). With the growing scarcity of drinking water worldwide, proactive strategic thinking and planning is necessary. Message: Investing in WATER Centers ensures that the public health and economic benefits for all things related to water is optimized. The WQQI could also be useful in longitudinal and cross-sectional epidemiological studies. Key messages The survival of the human population requires policy changes regarding water management. Mankind needs real-time feedback about water quality to respond to threats to the water supply.

One of the most important causes of river pollution is soil and water pollutions since no previous numerical studies linked the water quality indices and soil erosion parameters. The current research investigates the relationships between water quality parameters and indices versus parameters of soil erodibility (τc and kd) of Tigris Riverbanks within Baghdad City, Iraq. Besides, the research aims to create a new Iraqi Water Quality Index (IWQI) based on 10 parameters of water quality and compare the results with the Canadian Water Quality Index (CWQI). Finally, the research explores the spatial distribution of soil erodibility and water quality parameters using spatial analysis tools to produce forecast maps for water parameters and soil erodibility parameters. Forty samples of water and 30 samples of soil were collected from the five sites in Baghdad city during the winter and summer of 2019–2020. The mini-JET (miniature version of Jet Erosion Test) instrument was used to derive the soil erodibility parameters (τc and kd) for the five selected sites. The results showed that CWQI for all study sites of Tigris Riverbanks could be classified as inferior during the two seasons, while the new IWQI classified the water as good quality. The results showed that there was a relationship between water quality indices and soil erodibility parameters of Tigris Riverbanks. A direct relationship of two indices CWQI and IWQI versus τc was observed during the winter season with R2 of 0.86 for τc-CWQI and τc-IWQI. An inverse relationship between kd-CWQI and kd -IWQI with R2 of 0.90 and 0.86 was observed during the winter season. Similar results were obtained for the summer season but with low correlations of water quality indices versus kd. This research concluded that as water quality was poor, the soil erodibility was high.

Various pollutants have had a substantial impact on the quality of water in recent years. The quality of water directly impacts human health and the environment. The water quality index (WQI) is an indicator of effective water management. Water quality modelling and prediction have become essential in the fight against water pollution. The research aims to build an efficient prediction model for river water quality and to categorize the index value according to the water quality standards. The data has been collected from eleven sampling stations located in various locations across the Bhavani River, which flows through Kerala and Tamilnadu. The water quality index is determined by 27different parameters affecting water quality like dissolved oxygen, temperature, pH, alkalinity, hardness, chloride, coliform, etc. Data normalization and feature selection are done to construct the dataset to develop machine learning models. Machine learning algorithms such as linear regression, MLP regressor, support vector regressor and random forest has been employed to build a water quality prediction model. Support vector machines (SVM), naïve bayes, decision trees, MLP classifiers, have been used to develop a classification model for classifying water quality index. The experimental results revealed that the MLP regressor efficiently predicts the water Quality index with root mean squared error as 2.432, MLP classifier classifies the water quality index with 81% accuracy. The developed models show promising output concerning water quality index prediction and classification.

Seasonal assessment of the impact of fresh waters feeding the Bay of Gökova with water quality index (WQI) and comprehensive pollution index (CPI)

1 Department of Geography and Environmental Engineering, National Center for Earth-surface Dynamics, Johns Hopkins University, Baltimore, Maryland 21218 USA *Corresponding author; e-mail: M.A.KenneyPHD@gmail.com 2 Smithsonian Environmental Research Center, Edgewater, Maryland 21037 USA e-mail: sutton-griera@si.edu 3 Department of Entomology, 4112 Plant Sciences Building, University of Maryland, College Park, Maryland, 20742-4454 USA e-mail: rsmith9@umd.edu 4 Department of Biological Sciences, Towson University, Towson, Maryland 21252 USA e-mail: esens@tosgrwson.edu Received: 28 April 28, 2009; accepted: 17 July 2009 Summary is review addresses the intersection of water quality policy and benthic macroinvertebrates. Speci“ cally, we examine the role that stream macroinvertebrates have played or could play in informing water quality deci-sions given the current policy framework, using this framework as the organizational structure for the review. Macroinvertebrates, as biological indicators of stream water quality, can be utilized to identify impaired waters, determine aquatic life stressors, set pollutant load reductions, and indicate improvement. We present both current approaches as well as innovative approaches to identify macroinvertebrates and aquatic life stres-sors. We also discuss an example of the environmental management approach, speci“ cally, how macroinver-tebrates can be used to indicate the relative success of stream restoration. For policymakers, this review serves to illuminate opportunities and limitations of using benthic macroinvertebrates as indicators of water qual-ity. For entomologists, this review highlights policy-relevant research questions that would further aid the classi“ cation of impaired waters, the identi“ cation of stressors, or the management of stream ecosystems. © Koninklijke Brill NV, Leiden, 2009ds ywore Kiocriteria; B biological criteria; Clean ater ct; biological A W monitoring; bioassessment; essor str identi“ ca-tion; estoration; eam strr benthic tebrates eroinvmacr

The article considered the ecological index of water quality, which is used for planning water protection activities, developing water protection measures, carrying out ecological and ecological and economic zoning, ecological mapping; water pollution index, which is determined by hydrochemical indicators; modified Horton water quality index models; the Water Quality Index is proposed by the Canadian Council of Ministers of the Environment; the Said index, which is used to assess the quality of water for general use; water quality index in the river subbasin in a certain year; The Nemerov Pollution Index, which is used to comprehensively assess water, precipitation, or soil quality, and the Oregon Water Quality Index. Advantages and disadvantages of water quality and pollution indices are determined.

The Jimbitono River water quality was evaluated using epilithic diatoms as bioindicators, extending the Water Quality Index and the Water Quality Trophic Index. Three monitoring stations were found along the Jimbitono River with only one record. Physicochemical parameters such as pH, dissolved oxygen, biochemical oxygen demand, nitrates, phosphates, fecal coliforms, temperature, turbidity, total dissolved solids were analyzed. With the Water Quality Index, regular results were obtained for the PJ-01 and PJ-02 stations and poor for the PJ-03 station, the latter being explained by human interventions that are generated upstream of said station. In the analysis of epilithic diatoms, 1800 diatom organisms corresponding to 56 species were found, of which the most representative were Craticula molestiformis with 122 organisms. In the results of the Trophic Index of Water Quality, an oligotrophic level of negligible contamination was acquired for station PJ-01, for PJ-02 a ß-mesotrophic level of moderate contamination, and for PJ-03 an

Human societies rely on water to fulfill multiple needs. Paradoxically, our dependency on water has brought fundamental changes to freshwater ecosystems that may manifest as abrupt transitions in water quantity and quality indicators associated with conditions that can no longer fulfill human needs. Of particular concern amidst a time of environmental changes are tropical streams and their linked riparian zones, particularly in islands, given their role in the provisioning of water-derived ecosystem services. Focusing on a watershed that has become a key player in the water economy of Puerto Rico we investigated the spatiotemporal variation of water quality and socio-economic indicators, including links between them. The analyses of two unique datasets showed that 1) water quality indicators exhibited three distinctive behaviors, 2) in a small number of stations biological and chemical variables tended to decrease over time, 3) socio-economic indicators were spatially discontinuous, and 4) water quality and socio-economic indicators were related in counter-intuitive ways yet scale became a critical factor revealing the nature of the relationships. Our results raise questions about the causes underlying the observed variability in water quality and socio-economic conditions, the resilience of tropical watersheds, and ultimately the sustainable delivery of water-derived ecosystem services.

Diatoms and macroinvertebrates have been extensively used as water quality indicators in Europe for the last two decades. In Portugal, the use of biological indicators to assess water quality in rivers has increased greatly. The aim of this work was to assess the water quality and ecological status of the Ul River in order to evaluate its ability for the establishment of a fluvial beach, using periphytic diatoms and macroinvertebrates as indicators. Four sites were selected along the Ul River. At each site, biological, physical, and chemical parameters were investigated. Epilithic diatoms and macroinvertebrates were sampled. The Specific Polluosensitivity Index and the Biological Diatom Index were applied to diatom data, while for macroinvertebrates, the Iberian Biological Monitoring Working Party (IBMWP) was used. According to the results obtained, it was possible to conclude that up to now, this river does not possess the ideal conditions for the establishment of a fluvial beach. We concluded that epilithic diatoms and macroinvertebrates provided consistent information on water quality assessment and can be used as biological indicators of the water quality in Ul River.

This research aims at using a combined water quality index (WQI) and pollution index (PI) to assess and characterize river water quality of Cau River which is one of the longest rivers in the north of Vietnam. Five different water quality and water pollution indices were used including the Water Quality Index (WQI), Comprehensive Pollution Index (CPI), Organic Pollution Index (OPI), Eutrophication Index (EI), and Trace Metal Pollution Index (TPI). The combined water pollution indices show more serious pollution towards the river downstream. In particular, CPI and OPI reveal a high risk of eutrophication. Cluster analysis was applied to classify water monitoring points into different quality groups in order to provide a better understanding of the water status in the river. This study indicates that a combined water quality analysis could be an option for decision making water use purposes while its single index shows the current situation of water quality.

The impact of land use changes caused by urban sprawl on water quality since the 1970s in northern Georgia, USA is studied by examining the spatial and temporal relationships between land use and water quality indicators in 43 watersheds through geographic information system (GIS) and statistical analyses. GIS analyses are used to delineate watersheds using Digital Elevation Models for water sampling sites and to derive land use indicators such as urban land, forest, agricultural land, and wetland for each watershed. Statistical analyses are used to examine, quantify, and compare the relationships between water quality and land use indicators and to find good predictors of water quality changes in response to the spatial and temporal variations of land uses. Significant spatial relationships are found between all the 14 studied water quality indicators, including dissolved oxygen, specific conductance, dissolved nutrients, dissolved ions, dissolved solids, and suspended sediment, and two land use indicators (percentages of urban land and forest). The more urbanized watersheds with higher percentage of urban land and lower percentage of forest tend to have higher concentrations of water pollutants. However, no significant temporal relationships are found between water quality and land use indicators. To fully evaluate, explain, and predict water quality long-term change, it is necessary to consider more natural and anthropogenic factors, such as water pollution control technology, policy, and climate change.

Sachet water quality and Vendors’ practices in Damongo, northern Ghana during the emergence of SARS-CoV-2 using multivariate statistics, water quality and pollution indices, and panel assessment