Temporal Variations Of Water Quality Research Articles

Analysis of Spatial and Temporal Variation of Water Quality: A Case Study of Kotagala Wetland, Nuwara Eliya, Sri Lanka

Water quality of wetland ecosystems is a critical concern due to its implications on human health and aquatic life. This study was conducted to assess the spatial and temporal variation of water quality in Kotagala wetland to understand its impact on water safety for domestic uses and ecosystem health. Water samples were collected (n = 70) from six inlets and the wetland outlet from November 2021 to August 2022, and analyzed for pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), total suspended solids (TSS), nitrate, and phosphate. The pH, EC, and nitrate showed significant correlations. Spatial clustering divided the monitoring sites into two clusters, as areas of higher and lower pollution levels. Discriminant analysis highlighted the significance of EC, pH, and nitrate concentrations in differentiating these clusters. Principal According to principal component analysis (PCA) 88.8% of the total variance of spatial variation in water quality was explained by the first two components. Temporal clustering following seasonal variations revealed the influence of rainfall pattern on water quality. EC, TDS, TSS, and nitrate concentrations emerged as the most important factors in this temporal categorization. In PCA, 76.8% of the total variance of temporal variation in water quality was explained by the first two components. Findings highlight the urgent need for sustainable strategies and policies to mitigate the impacts of human activities on wetland water quality, since water quality variations in the wetland was significantly impacted by direct human activities, and variations in rainfall trends in the area.

Integrated environmental and social assessment of alum-contaminated water in An Giang province

ABSTRACT This study investigates alum-contaminated water in An Giang province within the Mekong Delta, emphasizing methodological approaches to assess its distribution and impacts. The research conducted from March to May 2021 involved surveys of residents, public sector employees, and provincial managers, complemented by expert interviews and extensive fieldwork. Surface water samples were collected during both rainy and dry seasons across three districts, with parameters such as turbidity, pH, and temperature measured onsite, and aluminum (Al), iron (Fe), and copper (Cu) concentrations analyzed in the laboratory using atomic absorption spectrometry. The data were further processed using QGIS software to create comprehensive maps illustrating seasonal variations in water quality. The findings revealed significant spatial and temporal variations in water quality, with pH levels fluctuating markedly between the dry and rainy seasons. Household surveys indicated a lack of awareness regarding effective water treatment methods, with most respondents relying on local authorities for solutions. The study highlights the need for community education and participation in addressing alum contamination, offering insights into the environmental and public health implications of water quality in the region. This research contributes valuable knowledge to the ongoing efforts in environmental conservation and water quality management in the Mekong Delta.

Characteristics of Water Environment and Its Influencing Factors in Zhari Namco Basin, Xizang

Zhari Namco is situated in the alpine grassland belt of northwestern Xizang with a fragile ecological environment. As the third-largest lake in Xizang, there has been a long-term lack of research data concerning its basin water environment. In an effort to elucidate the surface water environment characteristics of the basin and the factors influencing them, an extensive investigation was conducted from August 2021 to June 2022, encompassing periods of high flow, low flow, and base flow. Further, the study also involved comprehensive assessments of the water chemistry characteristics and spatial-temporal variation in lake sampling sites of the basin that were not significant by using mathematical statistics, hydrochemical analysis, correlation analysis, and principal component analysis. The findings revealed the following： ① The water in the Zhari Namco Basin exhibited an alkaline nature, with dominant ionic compositions in the lake comprising Na+, SO42-, and Cl-, whereas the rivers were primarily characterized by Ca2+, HCO3-, and SO42-. ② The main pollutants exceeding established standards included sulfates, arsenic, chlorides, and total phosphorus. The study identified significant spatiotemporal variations in water quality. Temporally, the exceedance of sulfates, arsenic, and total phosphorus was most pronounced during high-flow periods, followed by that during low-flow and base flow periods, with chloride levels showing less temporal variation. Spatially, river water quality surpassed that of the lakes, with arsenic, total phosphorus, TDS, sulfate, chloride, K+, and Na+ concentrations in lakes 1 to 2 orders of magnitude higher than those in rivers. Water qualities exceeding the established standard were primarily found in the lake, with less spatial variations within the lake itself. ③ Hydrochemical processes within the basin were found to be primarily influenced by natural phenomena, including evaporation-concentration and rock weathering. Various elements entered the lakes via surface runoff, where they continuously accumulated under the influence of evaporation-concentration processes, ultimately leading to exceedances. ④ Temporal variations in water quality were primarily attributed to increased elemental loss and intensified evaporation during high-flow periods. The spatial discrepancies in water quality were predominantly a consequence of the differing hydrodynamic conditions between flowing water bodies and enclosed water bodies.

Influence of hydroclimatic conditions and anthropogenic activities on the water quality of a floodplain lake (Argentina) during a warm season.

Contamination of water bodies, associated with urbanization, agricultural, and industrial activities, is a serious environmental challenge, with particular concern about microbial pollution due to its public health implications. This study is aimed at evaluating the spatial and temporal variations in the microbiological and physicochemical quality of a floodplain lake used for recreational purposes, whose watershed has been disturbed by diverse anthropogenic activities. The results showed that, while the spatial variation of water quality principally depends on the basin characteristics, temporal variation of water quality depends on land uses, hydrological conditions, and climatic conditions. Rainfall and rising water level intensified the influence of land use on the water quality by increasing concentrations of Escherichia coli, thermotolerant coliforms, and organic matter and decreasing dissolved oxygen. Thus, the residents and tourists are potentially exposed to microbiological risks given that it exceeds the international standards suggested for recreational waters on some occasions. It would be advisable to improve routine bathing water monitoring and management to preserve the health of the inhabitants and limit the recreational use of the water body in the days following heavy rainfall as well as during the beginning of the increase in the hydrometric level.

Assessing the water quality in urban river considering the influence of rainstorm flood: A case study of Handan city, China

The water quality of urban rivers is subject to fluctuation caused by rainstorm flood. The uncertainty of flooding in a dynamic environment brings about changes in river quality, presenting a significant challenge. Water samples were collected at 7 sampling sites in Handan City of China from January 2020 to August 2023, and 9 water quality parameters (WT, pH, Cond, Do, COD, BOD, NH3-N, TP, and TP) were analyzed. Specifically, the spatial and temporal variation of water quality in the Qingzhang River was analyzed. In terms of season, the concentration of water quality parameters in spring and winter was found to be significantly higher than that in summer and autumn. Spatially, the concentration of water quality parameters was lower in the upstream compared to the downstream. Furthermore, it was discovered that the reservoir had a purifying effect on the water quality of the river. Additionally, a comparison of water quality during flood and non-flood periods revealed that the concentration of water quality parameters in the upstream, midstream, and downstream of the Qingzhang River were higher during non-flood periods. These findings indicated that, in comparison to the urbanization factor, the hydrological factor, which results in the runoff carrying nutrients into the Qingzhang River, plays a crucial role in the change of its water quality. Moreover, the autoregressive integrated moving average (ARIMA) method was employed to create a water pollution emergency prediction model for the different sections of the Qingzhang River, and an adaptive urban river water purification strategy was formulated based on its variation patterns. The research results contribute to the theoretical basis for the management of urban rivers and water resources.

Spatial and Temporal Variability in Water Quality and Phytoplankton Community Composition in Charleston Harbor

The Charleston Harbor estuary is a dynamic ecosystem draining three rivers that surround the rapidly urbanizing greater Charleston area. Projected climate change impacts include elevated sea surface temperature and local changes in water quality that will likely alter biogeochemical cycling as well as phytoplankton abundance and community composition. Partnering with the local non-profit organization Charleston Waterkeeper, surface water samples were collected from late April through October 2021 at 20 sites in the Charleston Harbor estuary system. Water quality parameters measured included sea surface temperature (SST), salinity, pH, dissolved inorganic carbon, chromophoric dissolved organic matter (CDOM), phytoplankton pigments and nitrate and phosphate concentrations. Relatively high (6—16 μM) nitrate values were observed throughout the year and the nitrate to phosphate (N:P) ratios were consistently elevated (50—200) relative to the Redfield ratio of 16. Analysis of variance indicated that the delivery of nitrate, phosphate, and CDOM into the estuary came from upriver of the Charleston Harbor. For instance, CDOM was significantly impacted by tidal stage (p < 0.05) and was negatively correlated with salinity at low salinity sites, but no correlation was observed at high salinity sites. Seasonal patterns in phytoplankton community abundance and composition were driven by changes in SST, as overall phytoplankton biomass increased with a community shift from diatoms during colder months to flagellated cells such as prasinophytes during the warmer summer months. Phytoplankton diversity was greatest during the early summer and lowest in October. This study provides a reference baseline for water quality parameters and phytoplankton community composition in an estuarine ecosystem that is changing rapidly due to dredging and climate change processes.

Temporal Variation of Water Quality in Nilwala River, Southern Province, Sri Lanka

This study intended to investigate the temporal variation of water quality of the Nilwala river in the Matara district and to determine how the changes in rainfall affect to river water quality. Water samples were collected monthly from March 2019 to October 2019 (considering the second Inter monsoon season and first inter-monsoon season) at eight locations along the main river. Water quality parameters such as chemical oxygen demand (COD), biological oxygen demand (BOD), pH, electrical conductivity, temperature, alkalinity, hardness, chloride, nitrate and phosphate were analyzed using APHA 23rd edition of standard methods for the examination of water and wastewater. Experimental results were statistically analyzed by Two-way ANOVA using Minitab 17. The pH, EC, temperature, alkalinity and nitrate concentration showed statistically significant differences among the months (p<0.001) and those showed statistically significant differences with monthly rainfall (p< 0.001). There is a statistically significant relationship between rainfall and month (p<0.001). There is a statistically significant relationship between rainfall and sampling location (p<0.001). The highest rainfall was recorded from august to November (2nd inter-monsoon season) and secondly from March to May (1st inter-monsoon season) was recorded. Conductivity, pH and temperature were decreased from March to June. This may due to 1st inter monsoon rainfall. Conductivity was increased during august-november. Flooding can increase conductivity when it washes salts and minerals from the soil into the water. Nitrate concentration in the majority of the locations was increased during march-may. Total alkalinity, pH and nitrate were increased from august to November. The temperature of river water at all locations decreased from august- November. In conclusion, the pH, EC, temperature, alkalinity and nitrate concentration showed statistically significant differences among each month. It may due to variation of rainfall. Upper part of Nilwala River had a higher rainfall than lower basin.
 Keywords: Conductivity, Nilwala River, pH, temporal variation, Water quality

Study on the Spatiotemporal Variation in and Driving Mechanism of Water Quality in Baiyangdian Lake

Analyzing 165 data from five national control sites in Baiyangdian Lake, this study unveils its spatiotemporal pattern of water quality. Utilizing machine learning and multivariate statistical techniques, this study elucidates the effects of rainfall and human activities on the lake’s water quality. The results show that the main pollutants in Baiyangdian Lake are TN, TP, and IMN. Spatially, human activities are the main drivers of water quality, with the poorest quality observed in the surrounding village area. The temporal dynamics of water quality parameters exhibit three distinct patterns: Firstly, parameters predominantly influenced by point source pollution, like TN and NH4+-N, show lower concentrations during flood periods. Secondly, parameters affected by non-point source pollution, such as TP, show higher concentrations during flood periods. Thirdly, irregular variations were observed in pH, DO, and IMN. The evaluation of Baiyangdian Lake’s water quality based on the grey relationship analysis method indicates that its water quality is good, falling within Classes I and II. Time series analysis found that the dilution effect of rainfall and the scouring action of runoff dominate the temporal variation in water quality in Baiyangdian Lake. The major pollution sources were identified as domestic sewage, followed by agricultural non-point source pollution and the release of internal pollutants. Additionally, aquaculture emerged as a significant contributor to the Lake’s pollution. This research provides a scientific basis for controlling the continuous deterioration of Baiyangdian Lake’s water quality and restoring its ecological function.

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.

Spatial–Temporal Influence of Sand Dams on Chemical and Microbial Properties of Water from Scooping Holes in Degraded Semi-Arid Regions

Communities in semi-arid lands use sand dams to enhance access water during the dry seasons. However, there is limited information on the quality of water derived from these sand dams, especially in degraded lands where storm surface runoff poses contamination risk. Thus, this study aimed at assessing the spatial–temporal variations in water quality of sand dams in Chepareria, West Pokot County in Kenya. Water samples were collected from scooping holes across 18 purposefully selected sand dams. Results obtained showed significant differences in water quality based on a sand dam’s age and location of the scooping holes, but the magnitude of these differences differed with specific properties. For instance, in recently constructed sand dams (<1 year), scooping holes near the sand dam wall had lower pH values (8.5) than holes scooped a distance from the sand dam wall (9.2). For total dissolved solutes and microbial properties, sand dam age had the greatest impact, over the location of the scooping holes. For example, water obtained from <1 year old sand dams had significantly higher TDS with an average value of 100.3 mg L−1. The thermotolerant coliforms (TTC) exceeded the maximum allowable levels recommended by The World Health Organization. Thus, water obtained from these sand dams should be treated before consumption. Finally, sand dams meant for domestic water harvesting should be protected. Shallow wells with appropriate aprons for effective protection against contamination should be installed to enhance abstraction of safe water from sand dams.

Assessment of Spatial and Temporal Variation in Water Quality for the Godavari River

With increasing population and industrialization, the water quality of freshwater sources like rivers, lakes, and ponds is becoming increasingly degraded. Most of the rivers in India are becoming polluted, including the Godavari. With the construction of dams, new industries and unsustainable agricultural practices in the Godavari basin, the water characteristics are degrading spatially and temporally. The present study emphasizes the analysis of water quality parameters like temperature, pH, Dissolved Oxygen (DO), conductivity, Biological Oxygen Demand (BOD), nitrate, and faecal coliform concentration in the Godavari basin. This was achieved by analysis of data taken from the Central Pollution Control Board, India (CPCB) for 21 stations around the Godavari basin over a span of five years from 2015 to 2019. The Pearson Correlation coefficient for the water quality parameters was assessed to study the relationship among the parameters. Variation in the water quality parameter is observed from the graphs for each station for respective years. It was found that conductivity and DO, temperature and pH and DO and faecal coliform are negatively correlated. It was also observed that DO has a negative correlation with pH, BOD and faecal coliform, indicating the utilization of dissolved oxygen at higher rates due to increasing degradation of organic matter by aerobic microorganisms in the river. One-way ANOVA was applied to find out significant temporal variations and it was observed that temperature, pH, and faecal coliform level had significantly changed the overdue course of time (F(4, 115) = 2.451, p < 0.05). The obtained results from the analysis indicate that the selected water quality parameters have varied significantly spatially, whereas temporally, according to the ANOVA coefficient, only temperature, pH and faecal coliform had shown significant differences during the selected timeframe. Hence, the present study highlighted the deteriorating water quality of the Godavari River over time.

Assessment of Temporal Variation of Water Quality Parameters and Ecotoxic Trace Metals in Southern Nigeria Coastal Water

Assessment of Temporal Variation of Water Quality Parameters and Ecotoxic Trace Metals in Southern Nigeria Coastal Water

Variability in water quality of two meso-tidal estuaries of Odisha, East Coast of India

The increasing human population and rapid development along the east coast of India pose potential threats to coastal water quality. To assess the water quality of two tropical estuaries of Odisha, India, diurnal and seasonal variations along with the influence of differential anthropogenic impacts have been studied. From the results, it was evident, the seasonal variations in the water quality were largely influenced by anthropogenic sources at both the estuaries. Relatively lower seasonal variations in salinity were recorded in Mahanadi compared to Dhamara. Dissolved inorganic nitrogen (DIN) concentrations were found to be higher in the Dhamara estuary when compared to the Mahanadi estuary that can be attributed to decay of organic materials followed by the nitrification process. A reverse trend was recorded for dissolved inorganic phosphate (DIP), with significantly higher values recorded in Mahanadi. The partial pressure of carbon dioxide (pCO2) showed strong temporal variations in both the estuaries dominated by moderate CO2 supersaturation with respect to the atmosphere. The mean annual pCO2 was higher in the Mahanadi estuary and was largely attributed to its significant increase during the post-monsoon season. This study indicated the stronger influence of freshwater input and tidal activities compared to that of in situ biological processes in regulating the temporal variations in water quality of both the estuaries. The present study is helpful in understanding the natural state of the estuarine water and protection of ecosystems resources to fulfil the sustainable development at the regional level.

Variation of Water Quality in Intensive Aquaculture Areas of the Mekong Delta, Vietnam

The Mekong Delta produces about 70 % of Vietnam's national aquaculture output, and water quality management is a key factor in maintaining high levels of production and profitability. Effective water management strategies depend on understanding the spatial and temporal variations in water quality along major waterways. Therefore, this study aimed to assess the spatial and temporal fluctuation of water quality in the waterways of five provinces with intensive aquaculture operations in the Mekong Delta. The study sites included two inland provinces (An Giang and Can Tho) where striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878), is farmed, and three coastal provinces (Soc Trang, Bac Lieu, and Ca Mau) where white leg shrimp, Litopenaeus vannamei (Boone, 1931), and black tiger shrimp Penaeus monodon Fabricius, 1798, are cultured. At each sampling site, physicochemical parameters were monitored for 12 months on the main rivers which supply water to aquaculture systems. Water quality data were analysed and compared based on the coefficient of variation (CV), Pearson correlation coefficients to identify relationships among variables and principal component analysis (PCA) to identify 2–3 key parameters having the most significant influence on spatial and temporal variation in water quality in each province. BOD, COD, PO4 3-, S2-, NO2 - and NO3 - were highly variable (CV 40–120 %). Significant interrelationships ranged from -0.5 to 0.5 between many water quality parameters. Overall, water in most provinces was considered polluted. However, the water quality parameters, except for S2- and NO2 - , were within acceptable levels specified by National Technical Regulation on Surface Water Quality for Protection of Aquatic Life.

Evaluation of water quality of Mundeswari River in eastern India: a water quality index (WQI) based approach

The Mundeswari River is the western distributary of the Damodar River system in eastern India. The water of this river is extensively used for domestic purposes and agricultural irrigation. This study aimed to evaluate the spatial and temporal water quality variation of the Mundeswari River and assess the water quality status of this river using the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI). Water quality was monitored monthly at four selected sampling stations (M1, M2, M3, and M4) during 2020-2022, considering twelve selected water quality indicators. The obtained water quality data were analysed using different statistical techniques. Water quality at different monitoring stations was appraised through the use of CCME-WQI. The results revealed that the overall water quality of most of the monitoring stations based on CCME-WQI values was “marginal.” The highest WQI value (82.01) was observed at M1, and the lowest WQI (41.24) was recorded at M3. One-way ANOVA indicated a statistically significant difference in WQI values between sampling sites (P <0.05). The water quality of the M3 sampling station was found to be in degraded condition throughout the study period. Cluster analysis from the perspective of WQI values revealed two distinct clusters of the sampling stations. Substantial seasonal variation in water quality was also observed. This river had putrid water quality during the pre-monsoon period, and relatively better water quality was evident after the monsoon. This study revealed that the water of the Mundeswari River is utterly unsafe for human consumption and it requires significant treatments before it can be safely used for domestic purposes like cooking, washing etc.

TRANSFORMATION OF THE NORMALIZED DIFFERENCE CHLOROPHYLL INDEX TO RETRIEVE CHLOROPHYLL-A CONCENTRATIONS IN MANILA BAY

Abstract. Manila Bay is one of the most significant harbors in the region, enabling commerce and trade between the Philippines and other countries. Its abundant natural resources have provided for generations of its inhabitants and have driven socio-economic development for centuries. Like other water bodies adjacent to highly urbanized cities, the increased organic and nutrient loading from untreated domestic, industrial, and agricultural wastes resulted to further degradation of its water quality. While frequent water quality monitoring is ideal, data from traditional field sampling methods might not be sufficient to assess the spatial and temporal variations of water quality in Manila Bay. Remote sensing fills the need for a frequent and full overview of the bay’s water quality. Sentinel-3 images were initially processed through the Case 2 Regional CoastColour (C2RCC) model to retrieve the remote sensing reflectance. The Normalized Difference Chlorophyll Index (NDCI) was computed for the images and were modeled against the C2RCC-derived chlorophyll-a estimates. From this, we were able to get a general equation (TNDCI – transformed NDCI) to retrieve chlorophyll-a concentrations from two reflectance bands (Oa8 and Oa11). TNDCI gave an R2 of 0.9 and RMSE = 5.12 µg/L as compared to C2RCC values, and an R2 = 0.85 and RMSE = 2.44 µg/L with field data.

Data Integration for Investigating Drivers of Water Quality Variability in the Banja Reservoir Watershed

It is increasingly important to know the water quality of a reservoir, given the prospect of an environment poor in water reserves, which are based on intense and short-lived precipitation events. In this work, vegetation indices (NDVI, EVI) and bio-physical parameters of the vegetation (LAI, FC), meteorological variables, and hydrological data are considered as possible drivers of the spatial and temporal variability of water quality (WQ) of the Banja reservoir (Albania). Sentinel-2 and Landsat 8/9 images are analyzed to derive WQ parameters and vegetation properties, while the HYPE model provides hydrological variables. Timeseries of the considered variables are examined using graphical and statistical methods and correlations among the variables are computed for a five-year period (2016–2022). The added-value of integrating earth observation derived data is demonstrated in the analysis of specific time periods or precipitation events. Significant positive correlations are found between water turbidity and hydrological parameters such as river discharge or runoff (0.55 and 0.40, respectively), while negative correlations are found between water turbidity and vegetation descriptors (−0.48 to −0.56). The possibility of having easy-to-use tools (e.g., web portal) for the analysis of multi-source data in an interactive way, facilitates the planning of hydroelectric plants management operations.

Interaction among biofilter microbiome, fecal metabolome and water quality and regulation of sewage discharge in the recirculating aquaculture system of Apostichopus japonicus

With the aggravation of environmental pollution caused by traditional culture of Apostichopus japonicus, the concept of A. japonicus recirculating aquaculture system (RAS) came into being. To plan the sewage discharge time reasonably, we explored the temporal variation of water quality, biofilter microbe and fecal metabolome in RAS and relevant mechanism. The results showed that monitored water quality in RAS were within the safe living range of A. japonicus. Proteobacteria and Desulfobacterota were dominant bacteria in biofilter. The RDA results and correlation heatmap showed that NH4–N and NO2–N significantly affected the microbial community composition. The expression pattern of fecal metabolites changed with the passage of time after feeding. And ROC curve analysis and VIP bar chart showed that there were inter group biomarkers with predictive performance, which could help to remind timely sewage discharge. Topological analysis of KEGG pathway enrichment showed that metabolic pathways such as alanine, aspartate and glutamate metabolism changed significantly after feeding (P < 0.01). Additionally, the correlation analysis results showed that biofilter microbe and fecal metabolites were related to water quality (P < 0.05). Combined with the above research results, this study concluded that the RAS could discharge sewage 25–30 h after feeding. These findings were of direct significance to the management of RAS environment and the protection of A. japonicus healthy growth.

Spatial and Temporal Variations in Water Quality Along the Bua River, Malawi

Water quality in freshwaters is declining worldwide due to increases in human populations, expansion of agricultural activities, and climate change. There are quite a number of regions of the world, Africa inclusive, that are understudied, and little to no baseline information exists related to water quality. This study was focused on the Bua River in Malawi, which supports sustenance fishing and basic needs for local communities. A portion of the river has elevated levels of protection because it is found within the Nkhotakota Wildlife Reserve. The focus of this study was to understand the spatial-temporal variations of water quality at five sites in the Bua River from May 2018 to June 2020 capturing the three main seasons (warm wet, cool dry, and hot dry). Although other water quality parameters did not vary spatially. Spatially, the Bua River mouth registered the highest values of Soluble reactive phosphorus and the Bua River upstream had the lowest. However, there were greater temporal differences across seasons for water temperature, water pH, and chlorophyll a. For instance, chlorophyll-a was higher during the hot dry season (3.28 µgL-1) compared to the cool dry season (2.10 µgL-1) and warm wet season (1.91 µgL-1). Water transparency, as measured by secchi depth was lowest during the warm wet season, which coincides with higher concentrations in SRP. All measurements of salt content, Electrical Conductivity (EC), Total Dissolved Solids (TDS), and salinity) were higher during the hot dry season and correlated negatively with SRP. Similarly, bicarbonate and alkalinity were also higher during the hot dry season. Principle Component Analysis indicated that the parameters responsible for variations of Bua River water quality are mainly related to soluble minerals, water temperature, and surface runoff associated with agricultural activities and domestic waste accounting for 78.49 % of the total variance in the data set.

Temporal Variability in Water Quality and Phytoplankton Biomass in a Low-Inflow Estuary (Baffin Bay, TX)

Temporal Variability in Water Quality and Phytoplankton Biomass in a Low-Inflow Estuary (Baffin Bay, TX)