Temporal assessment of the water quality along an urban estuary (Tagus estuary, Portugal)

Rodrigues, Marta; Cravo, Alexandra; Freire, P.; Rosa, Alexandra; Santos, D.

doi:10.1016/j.marchem.2020.103824

Cited by 18 publications

(17 citation statements)

References 51 publications

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“…Typically, large bodies of water and deep water can promote disturbance and self-cleaning, which can directly affect the temperature and aquatic ecosystems, indirectly affecting the process of oxygen exchange in the water. The inverse correlation of temperature and DO, and DO with BOD and COD could mean that as temperature increases, DO decreases, and BOD and COD increase [14,47]. The fluctuations caused by turbidity, P-PO 4 3− , and Cl − in PC3 accounted for 10.4%.…”

Section: Key Water Variables Influencing Water Quality In the Water Bodies In Dong Thap Province In 2019mentioning

confidence: 99%

Spatiotemporal Analysis of Surface Water Quality in Dong Thap Province, Vietnam Using Water Quality Index and Statistical Approaches

Giao

Anh

Nhien

2021

Water

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The study was conducted to spatiotemporally analyze the quality, location and critical water variables influencing water quality using water monitoring data from the Department of Environment and Natural Resources, Dong Thap province in 2019. The water quality parameters including turbidity, pH, temperature, dissolved oxygen (DO), total suspended solids (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrite (N-NO2−), nitrate (N-NO3−), ammonium (N-NH4+), total nitrogen (TN), orthophosphate (P-PO43−), chloride (Cl−), oil and grease, sulfate (SO42−), coliforms, and Escherichia coli (E. coli) were collected at 58 locations with the frequency of four times per year (February, May, August, and November). These parameters were compared with national technical regulation on surface water quality—QCVN 08-MT: 2015/BTNMT. Water quality index (WQI) was calculated and spatially presented by geographical information system (GIS) tool. Pearson correlation analysis, cluster analysis (CA), and principal component analysis (PCA) were used to evaluate the correlation among water quality parameters, group and reduce the sampling sites, and identify key parameters and potential water pollution sources. The results showed that TSS, BOD, COD, N-NH4+, P-PO43−, coliforms, and E. coli were the significant concerns impairing the water quality. Water quality was assessed from poor to medium levels by WQI analysis. CA suggested that the current monitoring locations could be reduced from 58 sites to 43 sites which can be saved the total monitoring budget up to 25.85%. PCA showed that temperature, pH, TSS, DO, BOD, COD, N-NH4+, N-NO2−, TN, P-PO43−, coliforms, and E. coli were the key water parameters influencing water quality in Dong Thap province’s canals and rivers; thus, these parameters should be monitored annually. The water pollution sources were possibly hydrological conditions, water runoff, riverbank erosion, domestic and urban activities, and industrial and agricultural discharges. Significantly, the municipal and agricultural wastes could be decisive factors to the change of surface water quality in the study area. Further studies need to focus on identifying sources of water pollution for implementing appropriate water management strategies.

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Section: Key Water Variables Influencing Water Quality In the Water Bodies In Dong Thap Province In 2019mentioning

confidence: 99%

Spatiotemporal Analysis of Surface Water Quality in Dong Thap Province, Vietnam Using Water Quality Index and Statistical Approaches

Giao

Anh

Nhien

2021

Water

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“…Moreover, Gameiro et al (2004) observed that the spatial distribution of ammonium was correlated with sewage distribution. The implementation of wastewater treatment in the Tagus Estuary started in the 1990s, and its efficiency greatly improved during the 2000s (Rodrigues et al, 2020). Although treatment began in the 1990s, Gameiro and Brotas (2010), sampling in an inner zone of the estuary, did not find any differences in nutrient concentrations between 1980 and 2007, but more recently, Rodrigues et al (2020), sampling throughout the estuary, demonstrated a decline in all nutrients from the 1980s to 2019.…”

Section: Introductionmentioning

confidence: 99%

Tidal and Physicochemical Effects on Phytoplankton Community Variability at Tagus Estuary (Portugal)

Cereja

Brotas

Cruz³

et al. 2021

Front. Mar. Sci.

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The Tagus Estuary is one of the largest estuaries in Europe and merges large urban and industrial areas. Understanding phytoplankton community variability is key for an appropriate assessment of the estuarine ecological status. The objective of the present study was to assess the importance of the tidal influence over the phytoplankton community and to evaluate its main drivers of variation. Weekly sampling was performed at two stations on the Tagus Estuary with different anthropogenic pressures (Alcântara and Barreiro). The sampling covered periods with different tidal amplitude. Alcântara presented both the lowest and highest concentrations of dissolved inorganic nitrogen (DIN) and orthophosphate concentration (DIP), depending on the tidal height. Such high variability in this sampling station is probably due to its proximity to a sewage treatment station outfall and to the estuary mouth. In the present study, both seasonal and tidal variations influenced the chlorophyll a concentration of which the tidal cycle explained up to 50% of the chlorophyll a variations. Chlorophyll a displayed a seasonal trend with two peaks of phytoplankton biomass between spring and mid-summer. The main drivers of chlorophyll a variation were radiation, water temperature, tidal amplitude, salinity, river discharge, and the inorganic nutrients DIN and DSi. The estuarine phytoplankton community was mainly dominated by Bacillariophyceae, especially at Alcântara. Bacillariophyceae were less important at Barreiro, where communities had a higher representation from other phytoplankton groups, such as Cryptophyceae and Prasinophyceae. The drivers of variability in the community composition were similar to those influencing the total biomass. In conclusion, the spring-neap tidal cycle strongly influenced the phytoplankton community, both in terms of biomass and community composition. Of the several tidal conditions, spring tides were the tidal condition that presented both higher biomass and higher Bacillariophyceae representativity in the community.

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“…This validation was performed by comparison of the model results with the several datasets. The datasets included water levels data (Fortunato et al, 1999), salinity and water temperature data (Silva et al, 1986;Neves, 2010), and physical, chemical and biological data from synoptic field campaigns performed specifically for the UBEST observatory (Rodrigues et al, 2020). Some examples of the model results and error measures are presented in the supplementary materials.…”

Section: Model and Scenarios Descriptionmentioning

confidence: 99%

“…Historical data, available since the 1980s, provide an overview of how nutrients' concentrations evolved over time in the estuary and suggests that high loads of nutrients have been reaching the estuary over time (Rodrigues et al, in review). The use of indicators, computed from 2018 data, suggests that the nutrient chemical status presents "High" quality in the downstream and middle areas of the estuary and "Medium" quality further upstream (Rodrigues et al, 2020;Figure 4). TRIX also presents a similar pattern: in the downstream area of the estuary the trophic status is "High" to "Moderate", while in the middle estuary and upstream is "Moderate" or "Poor" (Figure 4).…”

Section: Assessment Of the Nutrients' Chemical Statusmentioning

confidence: 99%

A Web-Based Observatory for Biogeochemical Assessment in Coastal Regions

Rodrigues¹,

Martins²,

Rogeiro³

et al. 2021

J ENVIRON INFORM

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The concept of water observatories is extended to create a highly versatile tool for both the daily and the long-term management of estuarine ecosystems. Coastal observatories are evolving from simple data repositories to include forecasts, scenarios' analyses and indicators, integrated in web platforms that provide multiple products and services. In a context of climate change (CC) and growing anthropogenic pressures, the assessment of the ecological health implies that the biogeochemical status is adequately quantified and incorporated in the coastal management decision-making procedure. This quantification requires accurate models for hydrodynamics and ecology that account for all relevant processes at the right scales. These models must be applied in forecast mode for emergency purposes and in hindcast mode to explore multiple scenarios as part of the CC adaptation strategy, creating a complex, vast amount of information to be shared with the coastal managers. A web-based portal supported by a comprehensive modeling and forecasting framework and materialized along the main water quality/biogeochemistry themes, from data to indicators, is developed and demonstrated in two distinct yet complex coastal systems: the Tagus estuary and the Ria Formosa lagoon. The paper starts with the requirements analysis from both ecological and computer science perspectives and then presents the overall multi-layered architecture of the framework and its key software components. The observatory portal implementation and demonstration explore its usefulness for coastal management.

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Temporal assessment of the water quality along an urban estuary (Tagus estuary, Portugal)

Cited by 18 publications

References 51 publications

Spatiotemporal Analysis of Surface Water Quality in Dong Thap Province, Vietnam Using Water Quality Index and Statistical Approaches

Spatiotemporal Analysis of Surface Water Quality in Dong Thap Province, Vietnam Using Water Quality Index and Statistical Approaches

Tidal and Physicochemical Effects on Phytoplankton Community Variability at Tagus Estuary (Portugal)

A Web-Based Observatory for Biogeochemical Assessment in Coastal Regions

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