Water Quality Variables Research Articles

Assessment and Mapping of Water Quality in Urban Communities: Insights for Sustainable Development

Water quality is crucial for public health, ecosystem well-being, and sustainable development. However, ensuring access to safe and reliable water sources in urban communities takes time and effort. Assessing and mapping water quality in these communities is vital to understanding the current state of water resources, identifying potential contamination sources, and addressing health impacts. This descriptive study aims to assess and map water quality using clarity, color, odor, taste, safety, stability, and convenience parameters. Data were collected from eight sub-districts in Makassar City, South Sulawesi, and a questionnaire was administered through face-to-face interviews or electronic distribution. The study included 200 households selected through purposive sampling. The assessment revealed varying water quality among households, with the distribution as follows: good (46.0%), enough (29.0%), bad (19.0%), and poor (1.5%). Spatial mapping results indicated poor water quality in the Lakkang and Rappokalling sub-districts and inadequate water quality in the Lembo, Tallo, and Buloa sub-districts. Conversely, Wala-walaya and Bunga Eja Beru sub-districts exhibited good and sufficient water quality. The research underscores the importance of prioritizing water resource management and implementing measures for sustainable development goals. By doing so, we can enhance public health and preserve valuable ecosystems.

Assessment of Groundwater Hydrochemistry Using Multivariate Statistical Analysis Techniques and Aquachem (Piper Trilinear) the Case Study of Wabishable Basin, Ethiopia

To evaluate the spatial the characterization of the groundwater distribution of the Wabishable basin in Ethiopia using Multivariate statistical Analysis (cluster analysis and R-mode factor analysis) and Aquchem modeling. In this study use 13 physico-chemical parameters were selected Data sets from tested 107 wells samples which include: PH, calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), chloride (Cl), sulfate (SO4 ), bicarbonate (HCO3 ), nitrate (NO3 ), iron (Fe) TDS (total dissolved solid), electrical conductivity (EC). Based on Cluster analysis 107 sampling wells divided into two clusters grouped, such as fresh water (group1), and brackish water (group 2) based on the similarity of water quality characteristics. Factor analysis helped in identifying the factors or sources responsible for water quality variations. The varifactors obtained from factor analysis indicate that the parameters responsible for water quality variations are mainly related to water-rock interaction, agricultural activities and discharge recharge area. Further, SAR (0.28>SAR< 26.47), percent sodium (2.67 > %Na < 55.62). The overall water quality of the basin is good WQI (35 >WQI < 100) values recommended suitability for drinking water is (Good, 85%), for irrigation is (, Excellent, 95%), for Livestock (Good, 92%)

Long-Time Water Quality Variations in the Yangtze River from Landsat-8 and Sentinel-2 Images Based on Neural Networks

Total phosphorus (TP) and total nitrogen (TN) represent the primary water quality parameters indicative of the eutrophication status in the mainstream of the Yangtze River. Nowadays, satellite remote sensing offers an economical and efficient method for monitoring the water environment with a broad geographical scope, while single satellite and traditional methods are still limited. In this paper, inversion models of TN and TP are constructed and evaluated based on the neural networks (NNs) algorithm and random forest (RF) algorithm in the upper, middle, and lower reaches of the Yangtze River, respectively. Subsequently, the monthly variations of TN and TP concentrations are estimated and analyzed in the mainstream of the Yangtze River using Landsat-8 and Sentinel-2 satellites images from January 2016 to December 2022. The results show that the NNs model exhibits better estimation performance than the RF model within the study area. The accuracy of the TN model varies across different sections, with R2 values of 0.70 in the upstream, 0.67 in the midstream, and 0.74 in the downstream, accompanied by respective RMSE values of 0.21 mg/L, 0.21 mg/L, and 0.23 mg/L. Similarly, the TP model exhibits varying accuracy in different sections, with R2 values of 0.71 in the upstream, 0.69 in the midstream, and 0.78 in the downstream, along with corresponding RMSE values of 0.008 mg/L, 0.012 mg/L, and 0.008 mg/L. From 2016 to 2022, the concentrations of TN and TP in the mainstream of the Yangtze River exhibited an overall downward trend, with TN decreasing by 13.7% and TP decreasing by 46.2%. Furthermore, this study also gives the possible causes of water quality changes in the mainstream of the Yangtze River with a specific focus on hydrometeorological factors.

Seasonal differences in water quality of highland lakes and its influencing factors: A case study of Dianchi Lake

Abstract Water quality is of great significance to human survival and development. It is of good theoretical value to study seasonal water quality variation and driving factors in plateau lakes. This paper studied the variation of water quality parameters in different seasons and their relationship with land use and climate factors in Dianchi Lake, Yunnan Province from 2001 to 2019. The results show that the factors restricting water environment in different seasons are different, but basically close. The water quality parameters of multiple water quality monitoring stations in different seasons showed a decreasing or insignificant trend. In the rainy season, the temperature and precipitation were positively correlated with most water quality parameters, while the driving effect of climate factors was not significant in the dry season. Different land types have different effects on water quality indexes in different seasons. The water quality score was higher in the rainy season than in the dry season. The scores of water quality stations in the south and middle of Dianchi Lake are higher than those in the north. In this study, the relationship between climate, land, and water quality is established, which provides a way for the research of water quality parameters.

Spatio-temporal variations in sediment phosphorus dynamics in a large shallow lake: Mechanisms and impacts of redox-related internal phosphorus loading

The role of redox-related sediment phosphorus (P) release in shallow polymictic lakes remains poorly understood. Our previous studies in large and shallow Lake Peipsi suggested the importance of the redox-related P release in internal P loading. In the current study, we explored the validity of this hypothesis by also considering organic sediment P (Org-P). We analysed spatio-temporal changes in diffusive P flux and sediment P forms determined by P fractionation and nuclear magnetic resonance (NMR) spectroscopy in summer 2021. Using 1997–2021 data, we computed internal P load (IL) by two methods and studied their relationships with several water quality variables. Anoxia of sediment surfaces and P release progressed with an increase in water temperature during summer. In the long-term, IL estimates by two methods were similar (mean values: 315 and 346 mg/m2/year) and correlated with the predicted anoxia of sediment surfaces (AApred). A contribution of sediment iron-bound P (Fe-P) to P release was indicated by the positive correlation of Fe-P with orthophosphate (NMR) in the short-term studies. No similar evidence was found for Org-P, which contradicts the common tendency to attribute internal P loads largely to Org-P in eutrophic lakes. Nevertheless, organic matter seemed to support reductive dissolution, because seasonal changes in sediment Org-P correlated with those in Fe-P, and organic matter content and diffusive P flux were negatively correlated over different sites. Complex bottom morphology and hydrology affected spatial distribution of the sediment P forms and masked the relationships between sediment P variables and P release. Finally, the importance of redox-related release was reflected in significant relationships between AApred and associated IL with Secchi depth transparency, chlorophyll a concentration, and the biomass of phytoplankton and cyanobacteria. To our knowledge, this is the first time when such direct evidence was provided for a large polymictic lake.

Changes in midge assemblages reflect climate and trophic gradients across north temperate and boreal lakes since the pre‐industrial period

Abstract North temperate and boreal lakes are affected by a complex suite of anthropogenic stressors, yet little is known about how these ecosystems are faring across the most lake‐rich nation, Canada. The NSERC Canadian Lake Pulse Network is the first large‐scale national survey of its kind, with the aim of assessing the health of Canadian lakes, determined by the deviation of key variables from baseline pre‐industrial conditions (pre‐1880 CE). We examined midge remains (chironomids and Chaoborus) from modern and pre‐industrial sediment intervals in 67 lakes, spanning a range of sizes, ecozones, and degrees of catchment land‐use change. A marked northwest/southeast divide was evident in the modern chironomid assemblages, which was partially associated with water quality, physiographical and climatic variables, with a small portion of the variance explained by geography alone. Between the pre‐industrial and modern sediment intervals, taxa typically found in warmer waters increased across the country (p < 0.001); this pattern also was evident in the littoral assemblages (p = 0.01), providing additional support for the influence of warming. Turnover in chironomid assemblages varied across trophic classes. Mesotrophic lakes showed increases in macrophyte‐associated taxa, whereas eutrophic lakes showed declines in littoral taxa, perhaps reflecting increased turbidity, and the increase of low‐oxygen‐tolerant profundal taxa in eutrophic lakes with high human impacts. Overall, the distribution and dynamics of chironomid assemblages across Canadian lakes appear to be strongly linked to changes in climate and deep‐water oxygen conditions.

Water quality monitoring and assessment in coastal lagoons: Developing a protocol using a case study in Sainthamaruthu lagoon, Sri Lanka

AbstractSustainable water resources management requires monitoring and assessment of water quality in addition to quantity. Coastal lagoons play a critical role for the people and the ecosystem at large. Water quality monitoring and assessment for lagoons in Sri Lanka is important considering its services to the country. However, due to a lack of resources, most of the lagoons are not monitored and reported properly for further action. This study aims to develop a protocol in terms of monitoring sites, parameters, and frequency for water quality monitoring using a case study in a coastal lagoon, in Sainthamaruthu, Sri Lanka. The physicochemical parameters were measured weekly at eighteen monitoring sites for 4 months during the dry season from June to September 2022. Cluster analysis (CA) along with Inverse Distance Weighted (IDW) interpolation technique revealed that a minimum of three sites out of 18 are sufficient for monitoring water quality in the lagoon. In light of Principal Component Analysis (PCA) and Discriminant Analysis (DA), it was decided to retain temperature, pH, turbidity, Total Dissolved solids (TDS), Electrical Conductivity (EC), and Dissolved Oxygen (DO) in monitoring programs, since they cumulatively account for 79% of the variation in water quality in the lagoon spatially and temporally. Monitoring turbidity, TDS, and EC at weekly interval, while monitoring temperature, pH, and DO at biweekly or monthly is recommended. A further indication of the lagoon's water quality is that the mean values for turbidity (27 NTU), EC (754 μS/cm), and DO (4.6 ppm) higher than ambient standards, while TDS (344 ppm) and pH (6.98) are within. Therefore, we conclude that the lagoon requires remediation measures to be suitable for environmental purposes during dry periods.

Assessment of Riparian Ecosystem Health in the Tamiang River, Aceh, Indonesia as Remains Habitat of Batagur borneoensis (Schlegel & Muller, 1844)

The riparian zone along the Tamiang River, Aceh Province, is an important habitat for the survival of the tuntong laut (Batagur borneoensis) which is already threatened with extinction. This study aims to evaluate the quality and role of the riparian zone as a habitat for B. borneoensis along the Tamiang River, which can then be used as a reference in conservation. Riparian habitat quality was assessed by calculating the Qualitat del Bosc de Ribera (QBR) index, which was determined based on the total riparian cover, cover structure, cover quality, and channel alteration. In addition, observations of water quality (salinity, turbidity, and dissolved oxygen (DO)) and the number of riparian vegetation species were also carried out. Monitoring was carried out at five stations: Iyu River, Kampung Baru, Batang Lawang, Pusong Kapal Dermaga, and Pusong Kapal. The results showed variations in water quality between locations with DO and turbidity levels exceeding the quality standards set by the government. The richness of the types of riparian vegetation found ranged from 0-8 species (seedlings), 2-7 species (saplings), and 1-4 species (poles). The quality of riparian habitats in all study locations experienced significant degradation, including the euhemerobic and polyhemerobic (Hemeroby) categories, Cultural assisted system and Semi-transformed system (Naturalness), and Extreme degradation to poor-fair quality (QBR). The presence of B. borneoensis in the research location can adapt to the poor quality of riparian habitat. However, the density decreases significantly at higher salinity.

Significant Dynamic Disturbance of Water Environment Quality in Urban Rivers Flowing through Industrial Areas

The urban water environment is seriously affected by human activities. Rivers in highly industrialized areas, which often carry various types of industrial pollutants, such as metals and nutrients, are especially affected. In this study, the water quality of the Pi River, an industrial base that flows through Chengdu, a large city in Southwest China, was tested for one year. Heavy metal concentrations in the water, sediment, and macrobenthic and algal communities in the river were examined. The water pollution index (WPI) and trophic level index (TLI) were employed to measure the water pollution degree and eutrophication status, respectively. The Shannon—Wiener index (H’) and Margalef’s index (dM) were determined to represent the diversity and richness of macroinvertebrates. The principal component analysis (PCA) was employed to define the main heavy metal influencing factors in the Pi River. Our study showed that the eutrophication status increased with spatial change, and the eutrophication status was the most serious in the downstream reach, which was moderately eutrophic. The water body of the Pi River was seriously polluted by heavy metals, and the content of chromium (Cr) in the sediment and cadmium (Cd) in the water/sediment was far beyond the prescribed limit. In addition, we found that Cd had a serious impact on both the benthic and algal communities, and the benthic community structure was completely changed, destroying the original aquatic environment. We explored the mechanisms of the influence of Cd on aquatic fauna, and this information is of great significance for the future conservation of industrial urban rivers. In this study, the spatial–temporal variations in water quality and aquatic communities revealed the pollution status of a river flowing through industrial areas, which provided a basis for future river conservation and restoration.

Modeling in-stream biogeochemical processes at catchment scale: Coupling SWAT and RIVE models

Representation of biogeochemical in-stream processes is complex, and requires use of models to understand factors controling the transfer of contaminants on watershed scale. The biogeochemical model RIVE was integrated into the SWAT model and was used, instead of the current QUAL2E subroutine, to calculate biogeochemical in-stream processes. The coupled model was applied to an 89-km section of the Garonne watershed, downstream of Toulouse, for the 2000–2010 period, with a daily time-step. An epilithic biofilm equation was added to represent the river's algae communities, dominated by drifted benthic diatoms. The model matched observed data for major variables of water quality. Dominant processes for nitrogen, phosphorus, silica and organic suspended matter were assessed. The aim of coupling RIVE to the SWAT model was to improve the biogeochemical representation of the river's in-stream ecological processes linked to C, N, P and Si elements and dissolved oxygen, with minimal calibration.

Livestock water quality determination in small dams

The scarcity and low quality of water resources negatively impact food production processes. It is estimated that 8% of the world’s water supply is used in the livestock industries. This activity demands a large amount of water, which must be of high quality. Water quality monitoring in small dams for livestock allows for better decision-making in the management and water resources conservation. Such an approach avoids the risk of low production due to possible diseases. This work evaluated fourteen physicochemical parameters in samples from small dams. The results were used to build a water quality index in small dams (WQI-sd) for livestock. Seven water quality variables were chosen by using a Principal Component Analysis (PCA): electric conductivity, turbidity, chemical oxygen demand, dissolved oxygen, pH, total dissolved solids, and nitrates. These last three parameters are associated with negative welfare and production implications for the livestock. WQI-sd showed that 91% of the water samples were medium quality and the sample “Puerto La Palma” had bad quality. The water quality index for livestock in small dams could be used to generate information relatively quickly since it was built with 7 parameters, of which, more than 70% were determined in situ in a short time.

A holistic approach to the spatio-temporal variability investigation of the main river water quality – The importance of tributaries

The surface water pollution can cause serious ecological disasters. An example is large-scale fish deaths due to excessive salinity, which is global problem. In order to prevent such situations, it is necessary to carry out regular monitoring of both main rivers and their tributaries. The current monitoring system is neither adapted to the variability associated with the diversified use of catchments nor to changing climatic conditions. The Bzura River is one of the most anthropogenically transformed Polish rivers. So far, no comprehensive assessment of the chemical status of its catchment has been carried out. The presented research is a continuation of the study of the spatio-temporal variability of the Bzura chemistry. It covered 19 tributaries within the boundaries of the Łódź Voivodeship. Samples were collected once a month for one hydrological year. In total, 228 samples were obtained, in which 21 parameters were measured. Spatio-temporal variability of water quality on the basis of coefficients of variation (CVs) and water quality indices (WQIs) was evaluated. Principal component analysis (PCA) and cluster analysis (CA) were also performed. In addition, the datasets were visualized using geochemical maps. Combined monitoring with geospatial analysis brings benefits in terms of efficient control and management of water resources. The tributaries were divided according to the degree of their pollution. It was found that the electrical conductivity and concentrations of dissolved oxygen, nitrates, calcium and magnesium differentiated the tributaries in terms of pollution the most. The strong salinity from agricultural and geogenic sources was found. The WQIs were higher for the tributaries than for the Bzura. It suggests that the Bzura may be polluted by the tributaries under “favorable” climatic and hydrological conditions. Therefore, smaller watercourses should be included in monitoring and become more important in terms of an effective solution to global problem of surface water pollution.

Spatio-Temporal Variations in Water Quality and Fish Assemblages in Odoponyi Seasonal Stream as a response to disturbance from Selected Agricultural Landscapes in Tororo, Uganda

This study investigated the Spatio-Temporal Variations in Water Quality and Fish Assemblages in Odoponyi Seasonal Stream as a response to disturbance from Selected Agricultural Landscapes. Six sampling campaigns were launched at three different landscape sampling sites (grazing, rice plantation and sugarcane plantation) for 12 months from January to December of 2022. There was a general trend of increase in Dissolved Oxygen from upstream to downstream in sites in the catchment during both dry (from 7.13±1.9 to 8.9±2.1ppm) and wet seasons (from 11.2±2 to 12.3±01ppm). Plantation landscape of sugarcane registered the highest concentrations of nitrates during both dry and wet seasons (8±0.9 Mg/l and 11±1Mg/l) respectively. There was higher water transparency during dry season than wet season. A total of 568 fish individuals belonging to 7 species including Clarias leocephalus, Pamiphals promelas, Notemigonus crysoleucus, Anchoa mitchili, Poecilia reticulata, Barbodes binotatus and Pseudorasbora parva were captured using hand line and seine nets. Fish species diversity, richness and abundancy were higher during the wet season than dry season. Sugarcane plantation landscape registered the highest fish catch during both dry and wet season while grazing landscape registered the lowest catch at all times. This study recorded presence of a rare migratory fish species Notemigonus cryseleucus in wet season. We concluded that Odoponyi stream has migratory fish species that require protection especially during wet season. We recommended that land users in the catchment should leave a buffer strip of about 10m from the stream bank to reduce on the effect of erosion deposition directly into the stream.

Six decades of research on river temperature in Canada

River temperature is a key water quality variable in rivers and streams, as it modulates many other water quality variables as well as the metabolism, dispersion, and behavior of lotic biota. This paper reviews the key research milestones related to river temperature in Canada. The text focuses mostly on how research has been centrally motivated by the need to better understand and mitigate anthropogenic impacts on the thermal regime of rivers. The need for enhanced water temperature monitoring, both in situ and via remote sensing, especially in the Canadian North, is highlighted.

Water quality index, ecotoxicology and human health risk modelling of surface and groundwater along illegal crude oil refining sites in a developing economy

Water quality index, ecotoxicology and human health risk models were applied to surface and groundwater samples along illegal crude oil refining sites in Rivers State, Nigeria. Eight (8) surface water and four (4) groundwater sampling points were identified along illegal refining sites. Thirty-six (36) samples in triplicates were collected monthly from each of the twelve (12) sampling points over a three (3) month period. Water samples were collected and analyzed using standard methods as prescribed by the American Public Health Association. The mean pH for surface and groundwater ranged from 5.61 ± 0.15 to 7.34 ± 0.10 and 5.80 ± 0.10 to 6.39 ± 0.13, respectively. Turbidity, TDS, and BOD data for surface water samples exceeded the WHO guideline values. The ionic dominance pattern of anions for both surface and groundwater water samples were the same and in the order Cl− > SO42− > NO3− > PO42−. Mean heavy metal concentration was in the order Pb > Ni > Fe > Cd > Mn > Cu for surface water and Pb > Cd > Fe > Mn > Ni > Cu for groundwater. Cd and Pb concentrations in both sources were generally high, with Cd exceeding the WHO guideline value (GV). The CCME water quality index model ranked 62.5% of surface water as marginal, 12.5% as good, 12.5% as poor, and 12.5% as fair. The impact of heavy metals on public health was in the order Pb > Cd > Ni > Fe > Mn, with 83% of samples seriously affected by Pb pollution. The potential ecological risk index ranged from 1.61 × 103 to 2.64 × 103 for surface water and 8.10 × 102 to 2.21 × 103 for groundwater. Heavy metal contamination was very high, and the ecological risk effect was extremely high. The health risk through oral ingestion was in the order of adults > infants > children. Two principal components, PC1 and PC2, explained 50.51% and 16.00% of the variations in surface water quality, respectively. For groundwater quality data, three principal components explained the observed variations in water quality data, of which 51.39% is attributed to PC1, 26.29% to PC2, and 16.58% to PC3.

Combined Multivariate Statistical Techniques and Water Quality Index (WQI) to Evaluate Spatial Variation in Water Quality.

In present study, Water Quality Index (WQI) has been assessed of the Rawal Lake which is a major source of drinking water for people in the Federal Capital, Islamabad, and its adjacent city Rawalpindi in Pakistan. For this, the principal component analysis (PCA) and WQI were applied as an integrated approach to quantitatively explore difference based on spatial variation in 11 water quality parameters of the five major feeding tributaries of the Rawal Lake, Pakistan. The results of temperature in water, total dissolved solids, pH, electrical conductivity, chlorides and sulfates were well within the allowable World Health Organisation's (WHO) limits. However, the heavy metals like cadmium and lead were above permissible limits by the WHO in tributaries of Bari Imam and Rumli. Moreover, this has been proven by the Pearson correlation which suggested strong positive correlation (0.910*) between lead and cadmium. The results of present study were subjected to statistical analysis, i.e., PCA which gave three major factors contributing 96.5% of the total variance. For factor 1, pH, TDS, alkalinity, chlorides, sulfates and zinc have highest factor loading values (>0.60) and presented that these parameters were among the most significant parameters of first factor. As per the WQI results, the water was categorised in two major classes indicating that water of Bari Imam and Rumli is highly contaminated with heavy metals and totally unsuitable for drinking purposes. Based on the results of the present study, it is suggested to make heavy metals consideration as an integrated component in future planning for maintaining water quality of the Rawal Lake and its tributaries.

First Physico-Chemical and Traditional Characterisation of Lake Tseny, Northwest Madagascar

This study was designed to assess the biophysical structure, traditional practices and water quality of Lake Tseny in northwest Madagascar. The lake was divided into five zones: the central zone and the littoral zones (east, north, west and south). Transects and direct observation were used to estimate submerged tree and vegetation cover. Information on local traditions was collected through interviews with key people and visits to sacred sites. Water quality was assessed during the rainy and dry seasons, 2017–2018. Samples were taken twice a day, in the early morning and evening, at randomly selected points at intervals of 400m. The aquatic vegetation covered over 75% of the lakeshore. Most of the submerged tree trunks were recorded along the western area. Five sacred sites associated with eight forms of traditional taboos to reduce the potential source of water pollution were recorded in and around the lake. The lake is bowl shaped. The water was warm (T° 25.3 - 35.6 °C), slightly alkaline (pH 7.1 - 8.5), well oxygenated (DO 4.63 - 9.6 mg/l ) and less mineralised (EC 71.70 - 122.40 µS/cm). We found a seasonal difference in water quality between the rainy and dry seasons. Results showed spatial variation in water quality between zones. A comparison of the mean values with water quality standards showed that Lake Tseny has good water conditions for domestic purposes and suitable habitats for aquatic fauna throughout the year. These preliminary results provide reference data on the lake's characteristics. Due to the increasing human activities in the area, regular monitoring of water quality and physical characteristics should be carried out.

"Evaluating Water Health: A Review of Varied Water Quality Index Computation Techniques"

Abstract: The Water Quality Index (WQI) is a useful and distinctive assessment that summarises the state of the water supply in a single phrase, making it easier to choose the best treatment method to address the challenges at hand. WQI, on the other hand, illustrates the combined impact of several water quality measures and disseminates water quality data to the general public and legislative decision-makers. Despite the lack of a universally recognised composite water quality index, certain nations have utilised and are still utilising aggregated water quality data to construct water quality indices. There have been attempts to evaluate the WQI standards for the suitability of drinking water sources. The current article also emphasises and brings attention to the creation of a new, widely used "Water Quality Index" in a simpler format, which may be used to reflect an accurate representation of water quality.

The relationship between water pressure variations and drinking-water quality in small water supplies: A case of Mukono District, Uganda

The supply of a safe and adequate quantity of water is essential for human health and socioeconomic development. Physiochemical and microbiological quality of water supplied in piped distribution systems can be affected by long water residence times and travel distances. This may be due to low pressure, reservoir storage and insufficient disinfection in the system among other causes. As such, large schemes usually have mechanisms of improving the quality of water along supply and/or distribution networks at reservoir and other points. In contrast, small, piped water supply schemes rarely have the infrastructure and resources to monitor and provide treatment to the water in distribution. The objective of this study was to assess the variation of water quality and water pressure along the supply network in small, piped water systems. The study used mixed methods of quantitative water quality and pressure assessments, alongside stakeholder interviews, to investigate the variability of water pressure and specific water quality parameters across the distribution network, and reliability of supply in two different small water supply schemes in the study area of Mukono, Uganda. Results showed water pressure in small, piped water supply networks have minimal influence on variation of selected water quality parameters in smaller (< 4000 m travel distances) and well operated and maintained systems. A pressure drop from 82.2 m to 22.5 m changed Turbidity by < 1, Apparent Color by < x10 and Total Dissolved Solids by < x102. Proper management of supply systems to ensure optimal residual and continuous pressure can safeguard the quality of water in the distribution systems of small piped water networks against intrusion of contaminants. Good management practice that utilizes historical operational data with continuous capacity development and training support on water quality and pressure fluctuations can significantly improve system performance to meet acceptable standards.

Temporal evolution of suspended solids in the management of medium-sized watersheds in the Metropolitan Region of Paraíba Valley

The demand for water to meet the needs of the population has increased with the rapid growth of urban centers. The urban expansion in Taubaté (23.03º S, 45.55º W) negatively impacts the Una River Basin, a significant tributary of the Paraíba do Sul River, resulting in issues of sedimentation, siltation, and flooding. Systematic monitoring of sediment characteristics in human-influenced areas allows for an understanding of water quality variations, watershed diagnosis, and analysis of impacts on aquatic ecosystems, with total suspended solids (TSS) being a widely used parameter in this context. This study investigated the temporal evolution of the TSS concentration in the Una River, highlighting the importance of sound management practices to reduce sedimentation in urban catchments, through the analysis of biochemical parameters obtained from the Cetesb/Infoaguas platform. From 2008 to 2022, lower TSS concentrations were observed in winter (86.2 ± 35.6 mg L-1), while higher values were obtained in summer (779.7 ± 1024.8 mg L-1). In general, statistically significant correlations were found at the 95% confidence level between TSS and turbidity (Pearson's r = 0.93), dissolved oxygen (Pearson's r = -0.46), and electrical conductivity (Pearson's r = -0.43), while other evaluated parameters (pH, dissolved solids, and precipitation) did not show significant correlations. Among the key findings, it is crucial to study the temporal evolution of TSS and to implement sustainable management strategies in urban catchments, including erosion control measures and stormwater management, to preserve water quality, aquatic ecosystems, and water supply in the urban communities of RMVale.&#x0D; Keywords: basin, management strategies, sustainable, total suspended solids.