The Paraguaçu watershed in northeastern Brazil faces increasing water scarcity, with water resour... more The Paraguaçu watershed in northeastern Brazil faces increasing water scarcity, with water resources unable to meet the increasing demand. Accurate assessment of water availability is thus essential for efficient planning and management of local resources. In this work, the potential of the SWAT model for predicting daily and monthly variability of the hydrologic regime of the Paraguaçu River was assessed. Model calibration/validation followed: (i) A hierarchical framework; (ii) the assessment of maximum, average and minimum streamflow based on paired t-test and linear regression analysis; and (iii) the definition of permanence curves for streamflow with a probability of occurrence of 90% (Q90) and 95% (Q95). The goodness-of-fit indicators revealed a “satisfactory” model performance (model efficiency ranged from 0.42 to 0.83) when predicting streamflow in monitored sub-basins using a unique set of parameters for wet and dry conditions. The flow duration curves also showed that the m...
Water resources are impacted by several stressors like over-population and over consumption that ... more Water resources are impacted by several stressors like over-population and over consumption that compromises their availability. These stressors are expected to progressively intensify due to climate change in most regions of the world, with direct impact on watersheds and river systems. This study investigates the effect of different watershed pressure scenarios due to climate change in the hydrological regime of the Sorraia River basin, Portugal. This catchment includes one of the largest irrigated areas in the country, thus being strongly influenced by anthropogenic activities, associated to hydrological (irrigation, flow regulation, damming) and nutrient stressors. The Soil Water Assessment Tool has been used to simulate water flow and nutrient dynamics in the watershed while considering inputs from two climate models and three societal scenarios. Results have shown that the predicted rainfall reductions will have a significant impact on river flow and nutrient concentrations wh...
International Oil Spill Conference Proceedings, 2017
Abstract 2017-184: Accidental release of pollutants such as offshore oil spills can cause signifi... more Abstract 2017-184: Accidental release of pollutants such as offshore oil spills can cause significant negative impacts on the environment and socio-economy, and constitutes a direct hazard to marin...
One of the leading challenges in marine science and governance is to improve scientific guidance ... more One of the leading challenges in marine science and governance is to improve scientific guidance of management measures to mitigate eutrophication nuisances in the EU seas. Too few approaches integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic short term and long term nutrient reduction scenarios. As a step in this direction (ou in agreement), the main objective of EMoSEM was to link the eutrophication nuisances in specific marine regions of the North-East Atlantic (NEA) to river anthropogenic inputs, trace back their ...
Hydrological modeling is nowadays critical for evaluating the status, past trends, and future per... more Hydrological modeling is nowadays critical for evaluating the status, past trends, and future perspectives of water availability at the global, regional, and local scales. The Iberian Peninsula is registering more frequent and severe droughts and water scarcity caused not only by extreme meteorological events, but also by increased demand for water for urban, industrial, and agricultural supplies. Better simulation models are thus needed for accurately quantifying the availability of local water resources. In this study, the natural flow regime in different watersheds of the Iberian Peninsula was simulated using the process-based, fully distributed, MOHID-Land model from 1979 to 2013. Streamflow results were compared with measurements at 73 hydrometric stations not influenced by reservoirs, and with the data available in the management plans of each hydrographic region. The results showed a high dispersion of the goodness-of-fit indicators, with the coefficient of determination (R2)...
The success of an irrigation decision support system (DSS) much depends on the reliability of the... more The success of an irrigation decision support system (DSS) much depends on the reliability of the information provided to farmers. Remote sensing data can expectably help validate that information at the field scale. In this study, the MOHID-Land model, the core engine of the IrrigaSys DSS, was used to simulate the soil water balance in an irrigated vineyard located in southern Portugal during three growing seasons. Modeled actual basal crop coefficients and transpiration rates were then compared with the corresponding estimates derived from the normalized difference vegetation index (NDVI) computed from Sentinel-2 imagery. On one hand, the hydrological model was able to successfully estimate the soil water balance during the monitored seasons, exposing the need for improved irrigation schedules to minimize percolation losses. On the other hand, remote sensing products found correspondence with model outputs despite the conceptual differences between both approaches. With the necess...
Freshwater sources are essential inputs for regional ocean models covering coastal areas such as ... more Freshwater sources are essential inputs for regional ocean models covering coastal areas such as the western Iberian Peninsula. The problem is how to include the mixture between fresh and salt water, typically performed by estuaries and in the adjacent areas of river mouths, without unsustainable increases of computational time and human setup errors. This work provides a proof-of-concept solution to both these problems through the use of an offline two-way methodology, where local schematic rivers and estuaries are responsible for mixing river freshwater with salt water of a regional model application. Two different offline upscaling methodologies—which focus on the implementation of tidal fluxes from local domains to regional domains in the context of operational modelling—are implemented in the Portuguese Coast Operational Modelling System (PCOMS) regional model application as well as in a version without rivers. A comparison between results produced by these methodologies, field...
This study assessed the impact of climate change on the hydrological regime of the Paraguaçu rive... more This study assessed the impact of climate change on the hydrological regime of the Paraguaçu river basin, northeastern Brazil. Hydrological impact simulations were conducted using the Soil and Water Assessment Tool (SWAT) for 2020–2040. Precipitation and surface air temperature projections from two Regional Climate Models (Eta-HadGEM2-ES and Eta-MIROC5) based on IPCC5—RCP 4.5 and 8.5 scenarios were used as inputs after first applying two bias correction methods (linear scaling—LS and distribution mapping—DM). The analysis of the impact of climate change on streamflow was done by comparing the maximum, average and reference (Q90) flows of the simulated and observed streamflow records. This study found that both methods were able to correct the climate projection bias, but the DM method showed larger distortion when applied to future scenarios. Climate projections from the Eta-HadGEM2-ES (LS) model showed significant reductions of mean monthly streamflow for all time periods under bot...
This paper describes an integrated modelling approach to study water use vulnerability in a typic... more This paper describes an integrated modelling approach to study water use vulnerability in a typical Mediterranean basin under different climate change projections. The soil water assessment tool (SWAT) and the MOHID (from modelo hidrodinâmico) Water model were used to evaluate the impacts of two climate scenarios (GFDL-ESM2M and IPSL-CM5A-LR) on water availability in Montargil’s basin and reservoir (Portugal) during two decadal timelines (2030 and 2060). Reservoir performance metrics were estimated considering also two water demand scenarios: an average of the water demand in the last 10 years; and the largest annual demand of the last 10 years. The SWAT model results showed a future decrease of inflows to the reservoir, with its volumetric reliability decreasing from 100% in the historical simulation to about 60–70% in the IPSL-CM5A-LR climate scenario and 40–50% in the GFDL-ESM2M climate scenario. The time reliability also decreased to less than 30%, while the resiliency for the w...
The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state in the cou... more The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state in the country since its early years of operation. The problem has attracted water managers’ and researchers’ attention as the reservoir is the water supply for two municipalities. Extensive research was thus conducted over the last few years, including field monitoring and modelling at the plot, catchment, and reservoir scales. This study now frames all partial findings within the Driver-Pressure-State-Impact-Response (DPSIR) framework to better understand the eutrophication process in the Enxoé reservoir. Agriculture and grazing were found to have a reduced role in the eutrophication of the reservoir, with annual sediment and nutrient loads being comparably smaller or similar to those reported for other Mediterranean catchments. Flash floods were the main mechanism for transporting particle elements to the reservoir, being in some cases able to carry up three times the average annual load. Howev...
The Paraguaçu watershed in northeastern Brazil faces increasing water scarcity, with water resour... more The Paraguaçu watershed in northeastern Brazil faces increasing water scarcity, with water resources unable to meet the increasing demand. Accurate assessment of water availability is thus essential for efficient planning and management of local resources. In this work, the potential of the SWAT model for predicting daily and monthly variability of the hydrologic regime of the Paraguaçu River was assessed. Model calibration/validation followed: (i) A hierarchical framework; (ii) the assessment of maximum, average and minimum streamflow based on paired t-test and linear regression analysis; and (iii) the definition of permanence curves for streamflow with a probability of occurrence of 90% (Q90) and 95% (Q95). The goodness-of-fit indicators revealed a “satisfactory” model performance (model efficiency ranged from 0.42 to 0.83) when predicting streamflow in monitored sub-basins using a unique set of parameters for wet and dry conditions. The flow duration curves also showed that the m...
Water resources are impacted by several stressors like over-population and over consumption that ... more Water resources are impacted by several stressors like over-population and over consumption that compromises their availability. These stressors are expected to progressively intensify due to climate change in most regions of the world, with direct impact on watersheds and river systems. This study investigates the effect of different watershed pressure scenarios due to climate change in the hydrological regime of the Sorraia River basin, Portugal. This catchment includes one of the largest irrigated areas in the country, thus being strongly influenced by anthropogenic activities, associated to hydrological (irrigation, flow regulation, damming) and nutrient stressors. The Soil Water Assessment Tool has been used to simulate water flow and nutrient dynamics in the watershed while considering inputs from two climate models and three societal scenarios. Results have shown that the predicted rainfall reductions will have a significant impact on river flow and nutrient concentrations wh...
International Oil Spill Conference Proceedings, 2017
Abstract 2017-184: Accidental release of pollutants such as offshore oil spills can cause signifi... more Abstract 2017-184: Accidental release of pollutants such as offshore oil spills can cause significant negative impacts on the environment and socio-economy, and constitutes a direct hazard to marin...
One of the leading challenges in marine science and governance is to improve scientific guidance ... more One of the leading challenges in marine science and governance is to improve scientific guidance of management measures to mitigate eutrophication nuisances in the EU seas. Too few approaches integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic short term and long term nutrient reduction scenarios. As a step in this direction (ou in agreement), the main objective of EMoSEM was to link the eutrophication nuisances in specific marine regions of the North-East Atlantic (NEA) to river anthropogenic inputs, trace back their ...
Hydrological modeling is nowadays critical for evaluating the status, past trends, and future per... more Hydrological modeling is nowadays critical for evaluating the status, past trends, and future perspectives of water availability at the global, regional, and local scales. The Iberian Peninsula is registering more frequent and severe droughts and water scarcity caused not only by extreme meteorological events, but also by increased demand for water for urban, industrial, and agricultural supplies. Better simulation models are thus needed for accurately quantifying the availability of local water resources. In this study, the natural flow regime in different watersheds of the Iberian Peninsula was simulated using the process-based, fully distributed, MOHID-Land model from 1979 to 2013. Streamflow results were compared with measurements at 73 hydrometric stations not influenced by reservoirs, and with the data available in the management plans of each hydrographic region. The results showed a high dispersion of the goodness-of-fit indicators, with the coefficient of determination (R2)...
The success of an irrigation decision support system (DSS) much depends on the reliability of the... more The success of an irrigation decision support system (DSS) much depends on the reliability of the information provided to farmers. Remote sensing data can expectably help validate that information at the field scale. In this study, the MOHID-Land model, the core engine of the IrrigaSys DSS, was used to simulate the soil water balance in an irrigated vineyard located in southern Portugal during three growing seasons. Modeled actual basal crop coefficients and transpiration rates were then compared with the corresponding estimates derived from the normalized difference vegetation index (NDVI) computed from Sentinel-2 imagery. On one hand, the hydrological model was able to successfully estimate the soil water balance during the monitored seasons, exposing the need for improved irrigation schedules to minimize percolation losses. On the other hand, remote sensing products found correspondence with model outputs despite the conceptual differences between both approaches. With the necess...
Freshwater sources are essential inputs for regional ocean models covering coastal areas such as ... more Freshwater sources are essential inputs for regional ocean models covering coastal areas such as the western Iberian Peninsula. The problem is how to include the mixture between fresh and salt water, typically performed by estuaries and in the adjacent areas of river mouths, without unsustainable increases of computational time and human setup errors. This work provides a proof-of-concept solution to both these problems through the use of an offline two-way methodology, where local schematic rivers and estuaries are responsible for mixing river freshwater with salt water of a regional model application. Two different offline upscaling methodologies—which focus on the implementation of tidal fluxes from local domains to regional domains in the context of operational modelling—are implemented in the Portuguese Coast Operational Modelling System (PCOMS) regional model application as well as in a version without rivers. A comparison between results produced by these methodologies, field...
This study assessed the impact of climate change on the hydrological regime of the Paraguaçu rive... more This study assessed the impact of climate change on the hydrological regime of the Paraguaçu river basin, northeastern Brazil. Hydrological impact simulations were conducted using the Soil and Water Assessment Tool (SWAT) for 2020–2040. Precipitation and surface air temperature projections from two Regional Climate Models (Eta-HadGEM2-ES and Eta-MIROC5) based on IPCC5—RCP 4.5 and 8.5 scenarios were used as inputs after first applying two bias correction methods (linear scaling—LS and distribution mapping—DM). The analysis of the impact of climate change on streamflow was done by comparing the maximum, average and reference (Q90) flows of the simulated and observed streamflow records. This study found that both methods were able to correct the climate projection bias, but the DM method showed larger distortion when applied to future scenarios. Climate projections from the Eta-HadGEM2-ES (LS) model showed significant reductions of mean monthly streamflow for all time periods under bot...
This paper describes an integrated modelling approach to study water use vulnerability in a typic... more This paper describes an integrated modelling approach to study water use vulnerability in a typical Mediterranean basin under different climate change projections. The soil water assessment tool (SWAT) and the MOHID (from modelo hidrodinâmico) Water model were used to evaluate the impacts of two climate scenarios (GFDL-ESM2M and IPSL-CM5A-LR) on water availability in Montargil’s basin and reservoir (Portugal) during two decadal timelines (2030 and 2060). Reservoir performance metrics were estimated considering also two water demand scenarios: an average of the water demand in the last 10 years; and the largest annual demand of the last 10 years. The SWAT model results showed a future decrease of inflows to the reservoir, with its volumetric reliability decreasing from 100% in the historical simulation to about 60–70% in the IPSL-CM5A-LR climate scenario and 40–50% in the GFDL-ESM2M climate scenario. The time reliability also decreased to less than 30%, while the resiliency for the w...
The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state in the cou... more The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state in the country since its early years of operation. The problem has attracted water managers’ and researchers’ attention as the reservoir is the water supply for two municipalities. Extensive research was thus conducted over the last few years, including field monitoring and modelling at the plot, catchment, and reservoir scales. This study now frames all partial findings within the Driver-Pressure-State-Impact-Response (DPSIR) framework to better understand the eutrophication process in the Enxoé reservoir. Agriculture and grazing were found to have a reduced role in the eutrophication of the reservoir, with annual sediment and nutrient loads being comparably smaller or similar to those reported for other Mediterranean catchments. Flash floods were the main mechanism for transporting particle elements to the reservoir, being in some cases able to carry up three times the average annual load. Howev...
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