Papers

This paper presents a multi-criteria decision support methodology for selection and prioritization of rehabilitation intervention in urban water infrastructures considering performance, cost and risk and a long-term perspective. This methodology is divided into three main stages: problem identification, structuring and evaluation. Problem structuring, a crucial stage for the outcomes, includes identifying objectives, selecting scenarios within the analysis period, defining problem options and the problematic type. Problem evaluation includes the selection of assessment metrics, selection of the aggregation method, application of the method and sensitivity and robustness analysis and final recommendations. The methodology is applied to a real case study of a water distribution system, being the different stages presented in detail and obtained results discussed.

Climate trends suggest an increase in the frequency of intense rainfall events and the aggravation of existing conditions in terms of flooding in urban areas. In coastal areas, conditions are aggravated by coexistence with coastal overtopping. Flood risk control is complex, and the interdependencies among the services and sectors in urban areas imply the need for adoption of approaches that embrace the interplay between service providers to ensure critical urban functions. Flooding incorporates several hazards. Assessment of resilience to multiple hazards in complex environments benefits from integrated and multi-sectoral approaches. A common constraint resides in the limited data and tools available for undertaking these complex assessments. This paper proposes a risk-based methodology to assess urban areas’ resilience to flooding by addressing sectors’ interdependencies in a context of limited data and ready-to-use tools. Multisector flood risk identification is pursued with the support of a geographic information system and is applied to Lisbon with a focus on the cascading effects of drainage system failures on buildings, populations, mobility, waste management, and electricity supply. The results demonstrate the potential for combining data and knowledge from different sources with dual modelling approaches, thus allowing one to obtain trends of exposure and vulnerability to flooding for current and climate change scenarios. This methodology facilitates dialogue among stakeholders and decision levels by contributing to capacity building, and it contributes to sustainable development.

Night natural ventilation systems have been receiving increased attention in recent years because of their energy saving potential and environmental protection when used in passive instead of active cooling. A novel system recently proposed for cooling the building concrete slab is studied numerically in the present work. The system relies only on night ventilation as a means for cooling down the structure of the building. It consists of a new type of suspended ceiling with a peripheral gap between it and the walls combined with the positioning of the air supply and extraction grilles between the ceiling slab and the suspended ceiling. This study focuses on the use of Computational Fluid Dynamics (CFD) to predict the airflow and thermal performance of this strategy for an office room. Ansys-Fluent is used to perform the calculations both for a reduced and a full-scale room. Transient simulations were performed for a period of 24 h and the predictions for the reduced-scale model were validated by experiments under different operating conditions. The results show that the mathematical and numerical models provide satisfactory predictions of the temperature evolution in the reduced-scale model, allowing the analysis to be extended for full scale. The predictions for the office room at full scale confirm the effectiveness of the proposed cooling technique, revealing that the air peak temperature during the day is lower, as well as the temperature of the slab and the temperature of the air in the plenum during the night.

Este ensaio aborda a (re)invenção do espaço urbano a partir de lógicas cocriativas e, em específico, contempla o recurso feito a matéria azulejar no âmbito deste intuito. Por um lado, tendo por referência o Projeto Europeu C3Places, discute o potencial contributo da cocriação enquanto modus operandi do produzir espaço público urbano. Por outro lado, a partir de uma perspetiva exploratória, salienta determinados aspetos observados no decorrer de mapeamento de experiências cocriativas – em Portugal e no Brasil – que, em comum, recorrem ao azulejo na (re)invenção do espaço público. A reflexão destaca o potencial das iniciativas cocriativas no incrementar de sensibilidades coletivas com o património e o ambiente urbano. Observando que as mesmas não advêm de grandes ações, mas naquelas de menor âmbito, localizadas e de cunho colaborativo. O uso feito da matéria azulejar para a dinamização de ações coletivas e colaborativas é salientado. O que permite observar que, por um lado, a partir de uma lógica de continuidade-renovação, o recurso ao azulejo, viabiliza a invenção de património. Por outro lado, a aplicação de azulejo em espaço público protagoniza uma maior atenção coletiva com o ambiente urbano. A cocriação transformativa do espaço infere uma ligação à esfera pública, o que colabora para refletir sobre o papel que pode ter no incremento de práticas sociais mais envolvidas com os lugares urbanos e sensíveis à memória, ao património e ao ambiente.

The occurrence of a representative range of pharmaceutical compounds (PhCs) in urban wastewaters was studied in two Portuguese water-scarce regions (Lisbon great area, and Faro – Algarve), involving 55 sampling campaigns during 2.5 years. The results show 16 PhCs (out of the 24 analysed) were quantified in all samples, with similar concentrations in both wastewaters. To understand to what extent seasonality affects PhC occurrence, a statistical analysis was conducted, and daily maximum air temperature was identified as a key factor, with a turning point of 20°C in Lisbon and 22°C in Faro.

Artificial neural networks (ANN) are extremely powerful analytical, parallel processing elements that can successfully approximate any complex non-linear process, and which form a key piece in Artificial Intelligence models. Its field of application, being very wide, is especially suitable for the field of prediction. In this article, its application for the prediction of the overtopping rate is presented, as part of a strategy for the sustainable optimization of coastal or harbor defense structures and their conversion into Waves Energy Converters (WEC). This would allow, among others benefits, reducing their initial high capital expenditure. For the construction of the predictive model, classical multivariate statistical techniques such as Principal Component Analysis (PCA), or unsupervised clustering methods like Self Organized Maps (SOM), are used, demonstrating that this close alliance is always methodologically beneficial. The specific application carried out, based on the data provided by the CLASH and EurOtop 2018 databases, involves the creation of a useful application to predict overtopping rates in both sloping breakwaters and seawalls, with good results both in terms of prediction error, such as correlation of the estimated variable.

Performance assessment is essential to effectively evaluate and monitor the activity of water utilities, support decision making, and encourage continuous improvement. Performance assessment systems (PAS), covering several service objectives and criteria, have been successfully applied in water supply and wastewater systems. Tailored approaches focusing on the assessment of the energy use and efficiency in wastewater systems are still limited. This paper aims at the development and demonstration of a comprehensive PAS for energy efficiency, tailored for wastewater systems, incorporating criteria related to energy consumption, operation and maintenance (O&M) costs, and environmental impacts, such as untreated discharges and greenhouse gases emissions, among others. Management and control of excessive or undue inflows to these systems is specifically addressed by several novel criteria and metrics. The proposed PAS should be adapted by each utility to be aligned with the objectives of the organisation and with the implemented asset management strategy. The proposed approach and the resulting consolidated PAS are thoroughly described. Results from the application of the PAS to several Portuguese utilities are discussed. This PAS aims at contributing to a reliable and replicable process to assess energy efficiency in wastewater systems and to encourage a more rational energy management.

O projeto de investigação e desenvolvimento To-SEAlert financiado pela Fundação para a Ciência e a Tecnologia e envolvendo o LNEC, a FCiências.ID, a NOVA.ID.FCT e o ISEL tem como objetivo o desenvolvimento de um sistema de previsão, alerta, planeamento de emergência e gestão de risco de galgamentos e inundações em zonas costeiras e portuárias, com base no sistema HIDRALERTA. Partindo das características da agitação marítima ao largo e utilizando modelos numéricos para a propagação e deformação da agitação marítima, o sistema HIDRALERTA estima os parâmetros relevantes da agitação marítima para a avaliação do galgamento e da inundação bem como o risco associado a esses eventos. As funcionalidades que se pretendem melhorar no âmbito do projeto To-SEAlert dizem respeito às metodologias de previsão do galgamento e da delimitação da zona inundada, bem como no apoio à resposta a situações de emergência envolvendo fenómenos de galgamento. A implementação e a validação do protótipo do To-SEAlert estão a ser efetuadas para a zona costeira da Costa da Caparica e para o porto da Ericeira. Este artigo apresenta o trabalho desenvolvido até à data na construção e desenvolvimento do protótipo do To-SEAlert para o porto da Ericeira.

RESCCUE es un proyecto de investigación financiado por el programa Horizonte 2020 de la Comisión Europea y liderado por Suez que tiene como objetivo ayudar a ciudades de todo el mundo a ser más resistentes a retos físicos, sociales y económicos, utilizando el sector del agua como elemento central.