José Vieira

Eutrophication vulnerability analysis: A case study

River Cavado water quality variability was studied for eutrophication vulnerability assessment at a new surface water supply intake. Since the river flow regime is artificially controlled by upstream multipurpose reservoirs, mathematical modelling was applied in evaluating alternative management scenarios. Due to the fact that surface water quality at intake location is mainly affected by a wastewater treatment plant effluent discharge 5 km upstream, algae and nutrients concentration simulations have been worked out in order to identify critical situations. Different algal concentration profiles along the river were obtained for local conditions of light energy, water temperature and estimated nutrient loads, showing high probability of eutrophication occurrence for some of the simulated scenarios. The discussion of results of this study appears to be very useful for river basin wide water management policies evaluation.

Development and application of a model for regional water quality management.

Abstract A mathematical model has been developed for determining the optimal extent of regional water and wastewater treatment and wastewater diversion schemes in a river basin. Systems optimization was applied to minimize the overall cost of those schemes, taking into consideration the stream assimilative capacity and the prescribed levels of the surface water quality parameters. The model was tested in a real situation, determining the minimum cost, size and optimal location of the treatment scheme to be built in the River Ave basin in Portugal.

A strategic approach for Water Safety Plans implementation in Portugal

Effective risk assessment and risk management approaches in public drinking water systems can benefit from a systematic process for hazards identification and effective management control based on the Water Safety Plan (WSP) concept. Good results from WSP development and implementation in a small number of Portuguese water utilities have shown that a more ambitious nationwide strategic approach to disseminate this methodology is needed. However, the establishment of strategic frameworks for systematic and organic scaling-up of WSP implementation at a national level requires major constraints to be overcome: lack of legislation and policies and the need for appropriate monitoring tools. This study presents a framework to inform future policy making by understanding the key constraints and needs related to institutional, organizational and research issues for WSP development and implementation in Portugal. This methodological contribution for WSP implementation can be replicated at a global scale. National health authorities and the Regulator may promote changes in legislation and policies. Independent global monitoring and benchmarking are adequate tools for measuring the progress over time and for comparing the performance of water utilities. Water utilities self-assessment must include performance improvement, operational monitoring and verification. Research and education and resources dissemination ensure knowledge acquisition and transfer.

Estimating the potential water reuse based on fuzzy reasoning

Studies worldwide suggest that the risk of water shortage in regions affected by climate change is growing. Decision support tools can help governments to identify future water supply problems in order to plan mitigation measures. Treated wastewater is considered a suitable alternative water resource and it is used for non-potable applications in many dry regions around the world. This work describes a decision support system (DSS) that was developed to identify current water reuse potential and the variables that determine the reclamation level. The DSS uses fuzzy inference system (FIS) as a tool and multi-criteria decision making is the conceptual approach behind the DSS. It was observed that water reuse level seems to be related to environmental factors such as drought, water exploitation index, water use, population density and the wastewater treatment rate, among others. A dataset was built to analyze these features through water reuse potential with a FIS that considered 155 regions and 183 cities. Despite some inexact fit between the classification and simulation data for agricultural and urban water reuse potential it was found that the FIS was suitable to identify the water reuse trend. Information on the water reuse potential is important because it issues a warning about future water supply needs based on climate change scenarios, which helps to support decision making with a view to tackling water shortage.

Parameter estimation for eutrophication models in reservoirs

Excessive eutrophication is a major water quality issue in lakes and reservoirs worldwide. This complex biological process can lead to serious water quality problems. Although it can be adequately addressed by applying sophisticated mathematical models, the application of these tools in a reservoir management context requires significant amounts of data and large computation times. This work presents a simple primary production model and a calibration procedure that can efficiently be used in operational reservoir management frameworks. It considers four state variables: herbivorous zooplankton, algae (measured as chlorophyll-a pigment), phosphorous and nitrogen. The model was applied to a set of Portuguese reservoirs. We apply the model to 23 Portuguese reservoirs in two different calibration settings. This research work presents the results of the estimation of model parameters.

Numerical Modelling Of Oil Spills In Coastal Zones. A Case Study

A computational structure has been developed to forecast the time-space evolution of oil spills in marine environments. This structure was developed taking into account widely used mathematical formulations for oil spreading and weathering processes, A Eulerian transport model, that uses hydrodynamic results obtained with a two-dimensional and a quasi three-dimensional hydrodynamic model, was used to predict the oil slick transport and spread. This paper presents the general characteristics of the computational structure and the results of its application to a real case study: the Cereal accident in October 1994,

Pattern Recognition of the Household Water Consumption through Signal Analysis

This paper presents the initial results of a research project that aims to develop a method for losses/leakage detection and household water consumption characterization through the detailed patterns analysis of signals generated by water meters. The Department of Civil Engineering (University of Coimbra) supports the research as part of a PhD Project. An experimental facility is used for signals acquisition and data analysis will be performed by using a pattern recognition algorithm that will identify the hydraulic devices in use. It is intended to develop and test some algorithm structures at various plumbing configuration forms to find the best one. In a second phase, a consumption analysis will be carried out using that algorithm to test its efficiency in inhabited houses. The expectation is to develop an efficient water monitoring tool that helps the users to follow-up and to control the water consumption using a computer or even a mobile device.

Web-Based Decision Support Framework for Water Resources Management at River Basin Scale

In recent years a major effort has been done to make water quality modelling tools available for water resources management at a river basin scale. The European water framework directive clear states that these tools must be used in making the diagnostic of surface water bodies water quality status and to anticipate the impact of measures to be implemented in order to achieve a good ecological status by 2015 in European waters (European Commission 2000; Rekolainen 2003; Horn et al. 2004; Ravesteijn & Kroesen 2007; Volk et al. 2008).

Mathematical Modelling Of Oil Spills In TheAtlantic Iberian Coastal Waters

This paper presents an information system that is being developed as a management support tool for accidental oil spills in the Atlantic coastal waters of the Iberian Peninsula. Oil slick transport is predicted using a transport model (two-dimensional eulerian model implemented in the RMA4 program) associated with hydrodynamic models (two-dimensional models implemented in the RMA2 program and three-dimensional models implemented with the POM program). These hydrodynamic models can simulate tides, winds, river discharges and density gradients for induced currents. Data used to establish the models’ bathymetry and boundary conditions are also presented. Geo-referenced data are processed via a Geographical Information System tool. Data on the N/T Prestige oil spill processed by means of this information system and preliminary simulation results are also included.

Characterization of road runoff: A case study on the A3 Portuguese Highway

Road runoff is a linear non-point source of pollution with a significant impact on water receiving bodies, but whose importance has been neglected in the past. The pollutants in road runoff can be responsible for both acute and chronicle effects.