Water Quality In Basin Research Articles

Hydrogeochemistry and Water Quality Assessment in the Thamirabarani River Stretch by Applying GIS and PCA Techniques

The primary objective of this research is to assess the hydrogeochemical features and water quality of the Thamirabarani river stretch, located in southern India. Thirty-five water samples from the Thamirabarani river stretch were obtained from the districts of Tirunelveli and Thoothukudi. Twelve water quality parameters were measured during the pre-monsoon and post-monsoon periods of 2020 and 2021. The analytical results were verified with BIS and WHO standards to evaluate the water for drinking purposes. A Geographic Information system (GIS) was applied to know the spatial variation of the hydrogeochemical properties over the research area. Moreover, the Water Quality Index was calculated and it was revealed that 15% of the water samples used are outstanding, 35% are fit for potable use, 25% are poor, 15% water are very poor, and 10% unfit for consumption. Principal Component analysis (PCA) was performed to find out the dominant factors and their variance coverage for the overall water quality. The PCA results indicate that a water sample in Zone 1 is known for its alkalinity. The water qualities in Zone 2 and Zone 3 were affected by anthropogenic factors and industry wastes. More sea water intrusion was observed in Zone 4 in the water quality of the Thamirabarani river basin.

Comparison between graph theory connectivity indices and landscape connectivity metrics for modeling river water quality in the southern Caspian sea basin

The maintenance of connectivity is critical to the proper functioning of an ecosystem. The present study was conducted with the aim of comparing graph theory connectivity indices and landscape connectivity metrics for the purpose of modeling river water quality. To conduct this study, a forest layer was extracted from land cover map and 25 large watersheds were selected. River water quality was then assessed from the perspective of 8 landscape connectivity metrics and 12 graph theory indices. We developed predictive models using stepwise linear regression, power, exponential, and logarithmic models to locate the best model form for each water quality parameter (dependent variable) we examined. The results indicated that models developed using graph theory connectivity indices resulted in higher coefficients of determination (R2) than models developed using landscape metrics. Only 5 independent variables from a potential set of 13 were significant in explaining the variation in water quality parameters. Also, the models with the highest R2 attempted to explain variations in CO3 (0.818), water discharge (0.733), and Ca levels (0.702). Therefore, the results of this study showed that graph theory connectivity indices had more significant correlation with water quality parameters compared to landscape connectivity metrics. This work also indicates that there exist nonlinear relationships among connectivity indices and water quality parameters.

Retention Basin Water Quality in Tubuhue Urban Village North Central East Regency

The community carries out bathing and washing activities directly in the retention basin which can cause polluted water. Water quality checks need to be carried out before treatment. The purpose of this study was to determine the quality of water in the retention basin. Determination of the sampling location by purposive sampling. Sampling was carried out once in August 2021. Parameter measurements were carried out in the field and in the laboratory. The measurement results are compared with the quality standards listed in the Regulation of the Minister of Health of the Republic of Indonesia Number 32 of 2017 concerning Environmental Health Quality standards and Water Health Requirements for Sanitary Hygiene, Swimming Pools, Solus Per Aqua and Public Baths. A parameter that passed the quality standard was E-Coli while pH, hardness, nitrate, temperature, and TDS still met the quality standards. Retention basin water in Tubuhue Village seen from the parameters of temperature, pH, TDS, hardness, and nitrate can be used for sanitation hygiene purposes, but judging from the parameter E-Coli cannot be used for sanitary hygiene purposes.

Makrozoobenthos As A Bioindicator Of Water Quality In The Masang Kecil River In West Pasaman Regency

Sungai Masang Kecil is located in the middle of the PT Andalas Agro Industri (PT AAI) palm oil plantation and mill. This activity will have an impact on aquatic biota, especially benthos. Benthos occupies an important position in the food chain and lives permanently on the substrate to be used as a bioindicator of pollution. This study aimed to determine the Community Structure of Macrozoobenthos and the indicator species of water pollution in the Masang Kecil River around the PT AAI area, West Pasaman Regency. This research was conducted using a purposive sampling method with three sampling points, namely upstream and two downstream points after the Wastewater Treatment Plant (IPAL) and after the confluence of tributaries. Sampling using Surber net size 30 x 30 cm. The results of identifying the types of Bento's organisms as a whole identified as many as 45 species. Most species are found in Class Insecta. Based on the diversity index, the water quality in PT AAI's river basin was classified as unpolluted, and it could be concluded that the benthic condition was in good condition on a scale of 4. In the current study, the Diptera order as an indicator of polluted water was most commonly found among orders from other insect classes, namely, ten species. However, there were nine species from the Order Ephemeroptera as an indicator of clean waters and six species for Trichoptera.

A holistic assessment of spatio-temporal pattern and water quality in the typical basin of northeast China using multivariate statistical methods

The deterioration of water resources has been recognized as an urgent environmental problem due to population growth, industrialization, urbanization and agricultural activities, where water quality assessment is the basis for forward-looking decisions on water quality management. In this study, the Nemerow index method, traditional fuzzy mathematics and improved fuzzy mathematics methods were applied to assess the water quality of the Liao River based on twenty-three water quality parameters. The results revealed that most monitoring stations in the study area were moderately polluted. The improved fuzzy mathematics method gives more appropriate than the other two methods in water quality assessment. The self-organizing map (SOM) results suggested that chemical oxygen demand (CODCr) significantly affects water quality. The human health risk model was applied to calculate hazard indices (HI) to assess human health risks, indicating that the health risk of the Liao River caused by heavy metals was within an acceptable limit and did not pose a significant human health risk in the study area. Meanwhile, the health risk caused by heavy metals to children was higher than in adults. The results of the present study could provide new insights into water quality assessment, risk warning and public health protection in typical urbanized watersheds.

Evaluation of surface water quality in basins of the Chilean Altiplano-Puna and implications for water treatment and monitoring.

Water quality characterization and assessment are key to protecting human health and ecosystems, especially in arid areas such as northern Chile, where water resources are scarce and rich in pollutants. The objective of this study was to review and assess available official water quality data in the Chilean Altiplano-Puna basins for a 10-year period (2008–2018), including water treatment systems. Within the 43,600 km2 of Chilean Altiplano-Puna territory, only 16 official water quality monitoring stations had up-to-date data, and the sampling frequency was less than 3 per year. Most of the water samples collected at the evaluated stations exceeded the drinking and irrigation water Chilean standards for arsenic, boron, and electrical conductivity. Moreover, the characteristics of the Altiplano-Puna affect water quality inside and beyond the area, limiting water usage throughout the Altiplano-Puna basins. Drinking water treatment plants exist in urban and rural settlements; however, the drinking water supply in rural locations is limited due to the lack of adequate treatment and continuity of service. Wastewater treatment plants operate in some urban locations but rarely exist in rural locations. Limited data impede the proper assessment of water quality and thus the evaluation of the need for treatment systems. As such, the implementation of public policies that prioritize water with appropriate quantity and quality for local communities and ecosystems is imperative. Supplementary InformationThe online version contains supplementary material available at 10.1007/s10661-022-10628-1.

Effects of local land-use policies and anthropogenic activities on water quality in the upstream Sesan River Basin, Vietnam

Study regionThis study focuses on the upstream Sesan River Basin in the Central Highlands of Vietnam. Study focusLocal land-use policies and human activities can significantly affect hydrology and increase the magnitude of erosion and nutrients in downstream areas. The effects in terrestrial regions on water quality of the target area were evaluated during the 2000–2018 period using the SWAT (Soil and Water Assessment Tool) with updated land-use conditions following the local policy decisions and agricultural practices in different periods. New hydrological insights for the regionsThis study indicates that the implementation of the local land-use policies, along with extensive anthropogenic activities, has had significant effects on the downstream aquatic environment as compared with the period before the implementation of the land-use policies. Higher annual sediment, total nitrogen (TN), and total phosphorus (TP) loadings were found upstream from the Poko Watershed, where range land predominated, and in southern and southwestern Dakbla Watershed, where arable land and permanent cropland predominated. Arable land had the highest proportion of sediment and nutrient loadings into the reach, especially in the 2005–2009 period (conducting afforestation, agricultural expansion, and urbanization) and in the 2010–2014 period (applying crop conversion policy involving a shift from mixed forests to rubber forests). Understanding the watershed characteristics along with the combination of spatial land use, local land-use policies, and agricultural practices will support the implementation of regional land use and water resources management strategies more comprehensively.

The use of water quality index and water pollution index in assessing the water quality and suitability of the river Molo water basin, Kenya

Water quality assessment has become a very essential scientific procedure for qualifying water for drinking and general purpose use, and better public health policy on clean water supply. Various tools have been employed to determine the status of water systems for drinking, industrial and general use. For the purpose of this study, water quality index (WQI) and the recently developed water pollution index (WPI) have been adopted to evaluate the water of the Molo water basin. The world health organization (WHO) has defined limits of these parameters beyond which the quality of water is considered unsuitable for a specific use. The study was carried out in December, 2021 during the dry season. In this contribution, pH, conductivity, TDS, salinity, major cations and anions, and selected heavy metals were explored. Of the major cations Na reported the highest concentration at 1800 mg/L whereas in the anion category, the Cl gave the highest concentration at 110 mg/L. The highest pH, TDS and salinity were 8.5, 146.33, and 282.67, respectively. The data obtained were used to determine the water quality index (WQI) and water pollution index (WPI) of the Molo water basin based on the world health organization (WHO) standards. The average WQI obtained was 57.47 indicating that the water is slightly polluted. Also the average WPI obtained was 0.77 indicating that the water from the water basin is not of good quality. Sediment morphology and composition was also determined using energy dispersive X-ray spectroscopy (EDS). The findings showed the presence of heavy metal pollutants of concern which include lead, manganese and copper. Therefore, with respect to WQI, WPI and sediment morphology, the water basin is significantly polluted. There is need therefore for the government and health authorities to formulate policies aimed at regulating pollution activities which may endanger the Molo water basin.

Water Quality Index Classification Based on Machine Learning: A Case from the Langat River Basin Model

Traditionally, water quality is evaluated using expensive laboratory and statistical procedures, making real-time monitoring ineffective. Poor water quality requires a more practical and cost-effective solution. Water pollution has been a severe issue, hurting water quality in recent years. Therefore, it is crucial to create a model that forecasts water quality to control water pollution and inform consumers in the event of the detection of poor water quality. For effective water quality management, it is essential to accurately estimate the water quality class. Motivated by these considerations, we utilize the benefits of machine learning methods to construct a model capable of predicting the water quality index and water quality class. This study aims to investigate the performance of machine learning models for multiclass classification in the Langat River Basin water quality assessment. Three machine learning models were developed using Artificial Neural Networks (ANN), Decision Trees (DT), and Support Vector Machines (SVM) to classify river water quality. Comparative performance analysis between the three models indicates that the SVM is the best model for predicting river water quality in this study. In addition, there is a statistically significant difference in performance between the SVM, DT, and ANN models at the 0.05 level of confidence. The use of the kernel function, the grid search method, and the multiclass classification technique used in this study significantly impacts the effectiveness of the SVM model. The findings bolster the idea that machine learning models, particularly SVM, can be used to forecast WQI with a high degree of accuracy, hence enhancing water quality management. Consequently, the model based on machine learning lowered the cost and complexity of calculating sub-indices of six water quality parameters and classifying water quality compared to the standard IKA-JAS formula.

Water Quality Suitability of Padjadjaran Retention Basin (Indonesia) for Aquaculture in Sustainable Floating Pond

Padjadjaran Retention basin is an inland aquatic ecosystem in the form of a water basin that was newly flooded in 2021, located in Cileles Village, Jatinangor District, used as a water storage pond, irrigation source, and fishing. Around the waters there are human activities in the form of fisheries, agriculture, livestock and construction of the Cisumdawu Toll Road which can affect water quality physically and chemically. The purpose of the study was to determine the suitability of the water quality of the Padjadjaran Retention basin for aquaculture with a sustainable floating pond system. Water samples were collected from February to March 2022. The method used in this study is a survey, sampling is carried out using a random sampling method at three stations representing inlets, midlets and water outlets, measurement of water samples is carried out in situ which includes temperature, water transparency, pH, Dissolved oxygen and Carbon dioxide and ex situ measurements include Total suspended solid, Total dissolved solid, Ammonia, Nitrite, Hydrogen sulfide and Biochemical oxygen demand at the Aquatic Resources Laboratory of Padjadjaran University and the Tirtawening Environmental Quality Control Laboratory. The data were analyzed using the Water Quality Suitability Index (WQSI) according to Costa Pierce et al (1990), water quality standards refer to the Indonesian Government Regulation Number 22 of 2021, and Indonesian National Standard number 6494: 2013. The results showed that the water quality of Padjadjaran Retention basin is suitable for use for aquaculture, it is located near the outlet are more suitable for the placement of fish farming containers with a suitability index of 0.53, compared to in the inlet and in the midlet have a suitability index of 0.18 and 0.17, respectively.

Statistical process control in assessing water quality in the Doce river basin after the collapse of the Fundão dam (Mariana, Brazil).

The process of extracting information from data generated in environmental monitoring programs is often carried out using statistical tools, with Statistical Process Control (SPC) showing great potential for application in environmental monitoring. In November 2015, millions of cubic metres of tailings were dumped into the basin of the River Doce with the collapse of the Fundão dam. A study of the impact of this incident requires new approaches in data monitoring and processing, so it was sought to evaluate, using SPC tools, changes in water quality in the basin of the River Doce following the collapse of the dam. Using process charts and the process capability index (PCI), water quality parameters in the Doce and Carmo rivers were evaluated between 2009 and 2020. There, turbidity has improved since 2018, and Mn since 2016. Control charts showed that by December 2020 dissolved Fe was still not within normal pre-event fluctuation patterns. The PCI value showed that the situation worsened after the event for each of the parameters, with the lowest values for Mn and E. coli. By using a reference period, SPC makes it possible to infer the permanence of the impact of extreme pollution on the waterbody, which can be used in the routine monitoring of water quality in such events.

Water Security: Why We Need Global Solutions

Abstract The article introduces some of the general challenges of global water security (in the context of the availability of good quality water) and highlights the likely global impact of climate change, increasing pollution and population growth on water resources, including flooding and droughts, as outlined in recent studies. The nexus between water, food and energy is introduced, along with the concept of virtual water, and the desirability for society, industry and governments to consider water security in a global context. Cotton production and trading is considered as an example and how clothes purchased in a non-cotton producing country can have an adverse impact on the water quality and pollution levels in river basins in cotton producing countries and in any other countries further downstream in the river basin. The role and engagement of engineers is highlighted and how engineers can contribute significantly to addressing the challenges of Sustainable Development Goal 6, i.e., ‘ensure availability and sustainable management of water and sanitation for all’.

Determining water quality of the lower basin of the Usumacinta River in Tabasco, Mexico

Objective: The objective of this study was to determine the water quality of the lower basin of the Usumacinta River, based on its physicochemical and microbiological characteristics. Design/methodology/approach: There were taken 11 monthly samplings of surface water during the rainy season, from June to December, 2017 and in the dry season, from April to May, 2018, in three different sites. The parameters of temperature, pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), total phosphorus (TP) and Nitrogen nitrate (N-nitrate) were evaluated. Significant statistical differences (p≤0.05) between seasons and between sites were determined. Results: The results obtained were compared with Mexican regulations and Ecological Criteria for water quality. The parameters such as EC, TDS, TSS and total phosphorus showed substantial differences among seasons. The temperature, pH, EC and N-nitrate, did not exceed the maximum permissible limits for the use of irrigation water, urban public use and protection of aquatic life. However, the presence of E. coli and total coliforms from 530 to> 24 196 MPN/100 ml was recorded throughout the study period. Findings/conclusions: Parameters under study did not show significant differences between sites. The rainy season had an important effect on the increase in concentrations of TSS, TP, N-nitrate and total coliforms. Also, that maximum concentrations were recorded during the study period in the sampling sites of Boca del Cerro (R1) and Puente Chablé (R2).

Studying the tidal-induced water circulation pattern within EL-Burullus fishing harbor, Egypt, using CMS-PTM numerical modeling

Protection from waves and providing an appropriate calmness ratio are vital requirements in the designing phase of a harbor. Another crucial issue is guaranteeing sufficient water circulation as a key indicator for water quality and avoiding the associated environmental problems of poor water quality conditions. In a coastal harbor, the interior basin's water quality largely depends on the harbor's natural/self-ability to flush out different existing pollutants. El-Burullus fishing harbors is one of the Egyptian coastal fishing harbors that suffer from environmental issues such as accumulated pollutants, particularly in stagnant areas, and deterioration of water quality within the harbor's basin. Investigating water quality status within the coastal harbors necessitates knowledge about the mechanism of water circulation patterns within the harbor. The most common indicator for the water renewal and circulation pattern evaluation is the flushing time. Therefore, a coupled coastal hydrodynamic modeling system and particle tracking model (CMS-PTM) are utilized to investigate the tidal-induced circulation pattern within the El-Burullus fishing harbor, considering two tide scenarios (best and worst). Three locations (where most operational fishing facilities exist) were selected as point sources (instantaneous mass) for particle release. The results highlight the role of tidal actions on the water circulation within El-Burullus harbor and how the residence time varies based on the source release location.

Heavy metal levels and sources in suspended particulate matters of the glacier watersheds in Northeast Tibetan Plateau

This study collected summer meltwater runoff samples from several glacier watersheds of the northeast Tibetan Plateau during June-July 2017, and measured the concentrations of 17 trace elements (Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Mo, Cd, In, Sb, Cs, Ba) in meltwater suspended particulate matter (SPM), in order to reveal the elemental concentration, spatial distribution, and water quality in remote glacier watershed under regional anthropogenic activities. Results showed that, the concentration of heavy metal elements was relatively high in Yuzhufeng Glacier basin, ranging from 0.57 μg/L (In) to 1,551.6 μg/L (Ba), whereas in Qiyi Glacier basin it was the lowest, ranging from 0.02 to 85.05 μg/L; and relatively medium in other glacier watersheds, with total elemental concentration varying from 1,503.9 to 1726.2 μg/L. Moreover, enrichment factors (EFs) of SPM heavy metals showed significantly higher value in the downstream than that of upper glacier region of the watershed. Most heavy metals with low EFs mainly originated from crust dust, while others with higher EFs (e.g., Cd, Sb) probably originated from anthropogenic sources. Spatially, the EFs of heavy metals were higher in Yuzhufeng and Laohugou Glacier basins; while in other regions the EFs were relatively low, which may be caused by regional land-surface and atmospheric environmental differences surrounding the various glacier watersheds. Compared with other remote locations in global range, heavy metals level (e.g., Cu, Ni, and Zn) in this region is relatively higher. Meanwhile, we find that, though the water quality of the glacier basin in northeast Tibetan Plateau was relatively clean and pollution-free, it is still obviously affected by regional anthropogenic activities. Mining activities, transportation and natural weathering and erosion processes in the study areas have important effects on the content of heavy metal pollutants of river-water SPM in the glacier watershed. Moreover, backward air-mass trajectories demonstrated the potential atmospheric pollutants transport from the surrounding cities and suburbs, to deposit in the snowpack and glaciers, and then melted out and released into meltwater runoff. This study provides a new perspective on more complete view of heavy metals distribution in glacier watershed, and new understanding for the cryosphere water environment evaluation in the Tibetan Plateau region.

Improving surface water quality of the Yellow River Basin due to anthropogenic changes.

Understanding of how changes in diverse human activities and climate contribute to water quality dynamics is crucial for sustainable water environment management especially in the arid and semi-arid regions. This study conducted a comprehensive estimation of the surface water quality change in the Yellow River basin during 2003-2017 and its responses to varied pollution sources and water volumes under socioeconomic and environmental influences. Basin-wide measurements of chemical oxygen demand (COD), ammonium nitrogen (NH+4-N) and dissolved oxygen (DO) concentrations were used in trend detection. Annual anthropogenic (covering six sectors) and natural (sediment-induced, flow-in from the upstream and stored last year) pollution sources and water components (inflow, natural runoff, water consumption, reservoir storage and evaporation) were compiled for each sub-basin. Bottom-up hierarchical analysis was then performed to differentiate individual contributions. Results showed significant decreasing trends in COD and NH+4-N concentrations and increasing trends in DO concentrations. The middle reaches that traverse the Loess Plateau however remained severely polluted with 11.3-39.0% inferior to level III in 2017. The pollutant load played major positive contributions that gradually increased from upper to lower reaches. Declines in urban, rural and industrial pollution discharges following environmental investments and rural depopulation contributed the most: 78-96% for COD and 55-100% for NH+4-N. The total surface water volume had dilution effects in the upper and middle reaches (3-28%) and condensing effects in the lower reaches (2-37%). Precipitation and vegetation dynamics contributed slightly. The primary unfavorable factors were the growing agricultural pollution discharges and water consumption in the upper and middle reaches that also threatened the lower reaches. This study is expected to provide in-depth insights for the systematic response of regional water quality to combined human interventions and references for water quality management in other arid and semi-arid river basins worldwide.

Perspectives for review of the classification of water quality of the Benevente river basin from the use of frequency curves and water quality modeling

RESUMO Este trabalho discute a aplicação das curvas de permanência de qualidade como ferramenta para subsidiar decisões sobre o enquadramento de cursos d'água superficiais. A bacia hidrográfica do Rio Benevente (Espírito Santo, Brasil) constituiu a área de estudo. As cargas totais de DBO5,20 foram estimadas para diferentes seções de controle, considerando-se o esgotamento sanitário como a única fonte poluidora. Com o auxílio do modelo QUAL-UFMG, foram avaliadas as perspectivas de enquadramento associadas a diferentes cenários de simulação da autodepuração. As curvas de permanência de qualidade para o parâmetro DBO5,20 foram construídas para rios de água doce classes 1, 2 e 3. A capacidade de autodepuração do Rio Benevente permitiu a redução de 17% da carga total de DBO5,20 aportada. Independentemente do cenário de simulação avaliado, o Rio Benevente apresentou condições de qualidade usualmente mais próximas dos padrões estabelecidos para a classe 1 de enquadramento. Nesse sentido, ainda que não ocorra ampliação da cobertura do serviço de tratamento de esgotos, as curvas de permanência de qualidade para o parâmetro DBO5,20 apontaram condições para enquadramento mais restritivo dos cursos d'água da bacia hidrográfica do Rio Benevente do que aquele acordado no enquadramento legal.

Policy implementation through performance measurement: A study of water pollution remediation in China's Huai River Basin

AbstractPerformance‐oriented management has been proposed as a remedy to policy implementation failure, which is a persuasive woe globally. Recent scholarship on policy implementation through performance measurement and management focuses on client‐oriented services, with less attention paid to the inadequacy of performance indicators in covering all desirable policy goals and in incentivizing all government officials in a non‐client‐oriented service arena, for instance, environmental governance. Based on station‐level water quality data before and after the implementation of China's Huai River Basin Water Quality Accountability Program, we utilize a difference‐in‐differences (DiD) method to investigate how various water quality indicators in the Huai River Basin (HRB) have responded to the new personnel‐based performance measurement system which aimed to enhance environmental policy implementation at the local level. We show that the program succeeded in motivating government officials to meet targeted indicators, but it also led to the worsening of non‐targeted ones. We also find that the impact of this personnel‐based program was sensitive to personal and contextual factors: it affected younger local officials more strongly than those who were older and saw a more limited prospect for promotion. These findings provide evidence for the effectiveness of the personnel‐based measurement system, which may be considered by other countries, particularly those with authoritarian regimes and significant policy implementation failures. At the same time, complementary measures such as institutional arrangements that discover and report omitted important performance aspects, should be considered to safeguard the possible pitfalls of the system.

Simulation of ground water quality for noyyal river basin of Coimbatore city, Tamilnadu using MODFLOW

In recent years groundwater modelling has become a major part of many projects dealing with groundwater exploitation, protection and remediation. Coimbatore city is located along the Noyyal River which is grown in size and population on either side of the river and the dumping of wastes very close to the river banks, leads to pollution of both surface and groundwater. Study on the quality of groundwater along the Noyyal River in Coimbatore city of Tamilnadu, is necessary to safeguard the interest of the people with respect to quality and quantity of water. The objective of the research is to develop Groundwater quality models to suggest ways and means to contain and remediate the polluted groundwater under various conditions. Data related to the groundwater quality, rainfall and well log were collected from the reputed government departments and fifteen sample well locations are identified near the noyyal river basin. The quality parameters such as pH, TDS, EC, TH, chlorides, alkalinity, sodium, calcium, magnesium, sulphates and nitrates are considered for the study. Groundwater quality modelling is attempted by using MODFLOW/MT3DMS with different scenarios. This study revealed that in all the scenarios the center portion of study area is more affected i.e. from P·N.Palayam to Kalangal. The groundwater flow is moving towards and along the river flow. Hence the pollutants are moving easily from upstream to the downstream side. necessary measures has to be taken to control the groundwater contamination.

Remote sensing and machine learning based framework for the assessment of spatio-temporal water quality in the Middle Ganga Basin.

Understanding the dynamics of water quality in any water body is vital for the sustainability of our water resources. Thus, investigating spatio-temporal changes of dominant water quality parameters (WQPs) in any study is indeed critical for proposing the appropriate treatment for the water bodies. Traditionally, concentrations of WQPs have been measured through intensive fieldwork. Additionally, many studies have attempted to retrieve concentrations of WQPs from satellite images using regression-based methods. However, the relationship between WQPs and satellite data is complex to be modeled accurately by using simple regression-based methods. Our study attempts to develop a machine learning model for mapping the concentrations of dominant optical and non-optical WQPs such as electrical conductivity (EC), pH, temperature (Temp), total dissolved solids (TDS), silicon dioxide (SiO2), and dissolved oxygen (DO). In this context, a remote sensing framework based on the extreme gradient boosting (XGBoost) and multi-layer perceptron (MLP) regressor with optimized hyper parameters (HPs) to quantify concentrations of different WQPs from the Landsat-8 satellite imagery is developed. We evaluated six years of satellite data stretching spatially from upstream to downstream Ankinghat to Chopan (20 stations under Central Water Commission (CWC), Middle Ganga Basin) for characterizing the trends of dominant physico-chemical WQPs across the four clusters identified in our previous study. Through the developed XGBoost and MLP regression models between measured WQPs and the reflectance of the pixels corresponding to the sampling stations, a significant coefficient of determination (R2) in the range of 0.88-0.98 for XGBoost and 0.72-0.97 for MLP were generated, with bands B1-B4 and their ratios more consistent. Indeed, these findings indicate that from a small number of in-situ measurements, we can develop reliable models to estimate the spatio-temporal variations of physico-chemical and biological WQPs. Therefore, models generated from Landsat-8 could facilitate the environmental, economic, and social management of any waterbody.