Pedro Coelho’s research while affiliated with University of Lisbon and other places

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Publications (15)


Figure 1: Torrão reservoir watershed. Thiessen polygons. Water quality stations
Figure 3: Constituents observed values at three different depths: (a) an integrated sample between the reservoir surface and an average depth of 5.8 meters, (b) an average depth of 23 meters, and (c) an average depth of 43.7 meters. These observed values were compared with the predicted time series from the W2_SD_baseline (A to F) and W2_zero-order_baseline (SOD: 2.5 g/m²/day) (G to L) for the same depths.
Figure 5: Observed DO profiles (300 m from the dam) compared to predicted profiles using the W2_zero-order model (baseline), W2_SD model (Run 2) and (Run 5; baseline).
Figure A1: CE-QUAL-W2 bathymetry -Cross section of the Tâmega River with the average segment width
Main features of Torrão dam and reservoir

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Evaluating the performance of CE-QUAL-W2 version 4.5 sediment diagenesis model
  • Preprint
  • File available

January 2025

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17 Reads

Manuel Almeida

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Pedro Coelho

This study set out to assess the performance of the state-of-the-art CE-QUAL-W2 v4.5 sediment diagenesis model. The model was applied to a reservoir in Portugal using observed sediment particulate organic carbon values corresponding to a six-year period (2016–2021). The model was calibrated by comparing its results with 35 observed dissolved oxygen and water temperature profiles, as well as annual total nitrogen, total phosphorus, biochemical oxygen demand, and chlorophyll-a measurements corresponding to three different depths. In addition to model calibration, a sensitivity analysis was also conducted by varying the input particulate organic carbon values and applying a user-specified sediment oxygen model (zero-order model). The results demonstrated the overall effectiveness of the sediment diagenesis model, which accurately simulated dissolved oxygen profiles, nutrient concentrations, and organic matter levels (Dissolved oxygen profiles: NSE = 0.41 ± 0.67; RMSE = 1.73 mg/L ± 0.69), highlighting its potential as an effective tool for simulating lakes and reservoirs and supporting water management processes. The study further suggests that the zero-order model is able to serve as an effective starting point for implementing the sediment diagenesis model, providing an initial estimate for mean reservoir sediment oxygen demand (SOD) values.

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A first assessment of ERA5 and ERA5‐Land reanalysis air temperature in Portugal

August 2023

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164 Reads

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5 Citations

This study evaluates the reliability of ERA5 and ERA5‐Land reanalysis datasets in describing the mean daily air temperature of four climate domains in mainland Portugal. The reanalysis datasets were compared with ground observations from 94 meteorological stations (1980–2021). Overall, the results demonstrated a good degree of correlation between the observed and reanalysis data on both a daily and seasonal scale. Both the latitudinal distribution of the air temperature and the moderating effect of the Atlantic Ocean are well described. However, in the case of Portugal, the ERA5‐Land was shown to be considerably more effective at describing the mean daily air temperature than ERA5. The results also indicated that, in general, the reanalysis methodologies perform better when applied to air temperature simulation in flatter regions as opposed to regions with high‐altitude and complex terrain. The study further suggests that ERA5 and ERA5‐Land reanalysis should be used with caution in the case of short‐term environmental studies. In fact, relevant differences were shown to exist between the reanalyses and the observed daily mean air temperature datasets for certain specific years. Overall, considering the RMSE between the ERA5‐Land reanalysis datasets for mean daily air temperature and the observed datasets there is a 28% probability of locally having a mean RMSE <1.5°C, 52% probability of having a mean RMSE >1.5°C and <2.0°C, and 16% probability of having a RMSE >2.0°C and <3.0°C. These conclusions will hopefully contribute to improving our understanding of the uncertainty sources in relation to ERA5 and ERA5‐Land reanalysis data for different climate domains.



Citations (4)


... These data (and additional variables-see Section 3.2) were used to train and validate the models for streamflow prediction. No quality control measures were applied to the precipitation and temperature data, as previous studies have already demonstrated the relevance and reliability of ERA5-Land over the Iberian Peninsula and Portugal (e.g., [34,35]). ...

Reference:

Deep Learning Prediction of Streamflow in Portugal
A first assessment of ERA5 and ERA5‐Land reanalysis air temperature in Portugal

... Consisting of interconnected neurons, ANN models can recognize patterns, classify information, make predictions, and learn, just like the human brain functions (Agbasi and Egbueri 2024). Machine learning and neural networks have become practical tools for regulating water quality, among other environmental issues, and received more attention for evaluating water parameters and quality in aquatic ecosystems utilizing a variety of ecological factors as model inputs and learning rates, as opposed to data-driven conventional statistical approaches (Liu et al. 2013;Chou et al. 2018;Ma et al. 2020;Huang et al. 2021;Politikos et al. 2021;Shah et al. 2021;Wang et al. 2021;Almeida and Coelho 2023;Souaissi et al. 2023;Zheng et al. 2023). Heddam (2016) introduced two AI models, namely radial basis function neural network (RBFNN) and multilayer perceptron neural network (MLPNN), to predict the hourly DO using four parameters, i.e., temperature, pH, specific conductance, and sensor depth as model features. ...

An integrated approach based on the correction of imbalanced small datasets and the application of machine learning algorithms to predict total phosphorus concentration in rivers
  • Citing Article
  • May 2023

Ecological Informatics

... For example, systematic data collection at multiple sites in the work of [42] contributed to a more robust model. Furthermore, studies focusing on more direct parameters, such as water level and temperature [26], generally achieved higher R 2 values than those addressing more complex parameters, such as dissolved oxygen and chlorophyll-a [23]. These observations are reflected in the analyses of various studies that applied the CE-QUAL-W2 model, revealing significant differences in the quality of methods, which can directly impact the obtained R 2 values. ...

Long-Term Water Quality Modeling of a Shallow Eutrophic Lagoon with Limited Forcing Data

Environmental Modeling & Assessment

... The graphic method is based on exploring the relationship between the shape characteristics of FDC and the climate and geomorphologic characteristics of the catchment, such as the steepness or quantile of the curve, to estimate the shape of the FDC, which represents the flow condition of unmeasured catchments (Mohamoud, 2008). The statistical method aims to fit the empirical FDC through appropriate distribution functions (such as gamma distribution, lognormal distribution, generalized Pareto distribution, kappa distribution, etc.) (Almeida et al., 2021;Burgan & Aksoy, 2022;Cheng et al., 2012;Ghotbi, Wang, Singh, Blöschl, & Sivapalan, 2020;Ghotbi, Wang, Singh, Mayo, & Sivapalan, 2020;Shin & Park, 2022), and then find the quantitative and qualitative relationship between the estimated parameters of the fitting function and the characteristics of the local climate and geographical environment of the measured catchment. Villalobos and Neelin explained why the gamma distribution can well fit the daily precipitation distribution. ...

The probability distribution of daily streamflow in perennial rivers of Angola
  • Citing Article
  • August 2021

Journal of Hydrology