14,446 research outputs found
Heat risk assessment for the Brussels capital region under different urban planning and greenhouse gas emission scenarios
Urban residents are exposed to higher levels of heat stress in comparison to the rural population. As this phenomenon could be enhanced by both global greenhouse gas emissions (GHG) and urban expansion, urban planners and policymakers should integrate both in their assessment. One way to consider these two concepts is by using urban climate models at a high resolution. In this study, the influence of urban expansion and GHG emission scenarios is evaluated at 100 m spatial resolution for the city of Brussels (Belgium) in the near (2031-2050) and far (2081-2100) future. Two possible urban planning scenarios (translated into local climate zones, LCZs) in combination with two representative concentration pathways (RCPs 4.5 and 8.5) have been implemented in the urban climate model UrbClim. The projections show that the influence of GHG emissions trumps urban planning measures in each period. In the near future, no large differences are seen between the RCP scenarios; in the far future, both heat stress and risk values are twice as large for RCP 8.5 compared to RCP 4.5. Depending on the GHG scenario and the LCZ type, heat stress is projected to increase by a factor of 10 by 2090 compared to the present-day climate and urban planning conditions. The imprint of vulnerability and exposure is clearly visible in the heat risk assessment, leading to very high levels of heat risk, most notably for the North Western part of the Brussels Capital Region. The results demonstrate the need for mitigation and adaptation plans at different policy levels that strive for lower GHG emissions and the development of sustainable urban areas safeguarding livability in cities
Mapping Europe into local climate zones
Cities are major drivers of environmental change at all scales and are especially at risk from the ensuing effects, which include poor air quality, flooding and heat waves. Typically, these issues are studied on a city-by-city basis owing to the spatial complexity of built landscapes, local topography and emission patterns. However, to ensure knowledge sharing and to integrate local-scale processes with regional and global scale modelling initiatives, there is a pressing need for a world-wide database on cities that is suited for environmental studies. In this paper we present a European database that has a particular focus on characterising urbanised landscapes. It has been derived using tools and techniques developed as part of the World Urban Database and Access Portal Tools (WUDAPT) project, which has the goal of acquiring and disseminating climate-relevant information on cities worldwide. The European map is the first major step toward creating a global database on cities that can be integrated with existing topographic and natural land-cover databases to support modelling initiatives
Predicting the Impact of Climate Change on Thermal Comfort in A Building Category: The Case of Linear-type Social Housing Stock in Southern Spain
The Climate Change scenario projected by the IPCC for the year 2050 predicts noticeable
increases in temperature. In severe summer climates, such as the Mediterranean area, this would
have very negative e ects on thermal comfort in the existing housing stock, given the current high
percentage of dwellings which are obsolete in energy terms and house a population at serious risk of
energy poverty. The main aim of this paper is to generate a predictive model in order to assess the
impact of this future climate scenario on thermal comfort conditions in an entire building category.
To do so, calibrated models representing linear-type social multi-family buildings, dating from the
post-war period and located in southern Spain, will be simulated extensively using transient energy
analyses performed by EnergyPlus. In addition, a sensitivity analysis will be performed to identify
the most influential parameters on thermal discomfort. The main results predict a generalized
deterioration in indoor thermal comfort conditions due to global warming, increasing the average
percentage of discomfort hours during the summer by more than 35%. This characterization of the
future thermal behaviour of the residential stock in southern Spain could be a trustworthy tool for
decision-making in energy retrofitting projects which are so badly needed. To do so, further work
is required on some limitations of this model so that di erent user profiles and typologies can be
represented in detail and an economic assessment can be included
The Air-temperature Response to Green/blue-infrastructure Evaluation Tool (TARGET v1.0) : an efficient and user-friendly model of city cooling
The adverse impacts of urban heat and global climate change are leading policymakers to consider green and blue infrastructure (GBI) for heat mitigation benefits. Though many models exist to evaluate the cooling impacts of GBI, their complexity and computational demand leaves most of them largely inaccessible to those without specialist expertise and computing facilities. Here a new model called The Air-temperature Response to Green/blue-infrastructure Evaluation Tool (TARGET) is presented. TARGET is designed to be efficient and easy to use, with fewer user-defined parameters and less model input data required than other urban climate models. TARGET can be used to model average street-level air temperature at canyon-to-block scales (e.g. 100 m resolution), meaning it can be used to assess temperature impacts of suburb-to-city-scale GBI proposals. The model aims to balance realistic representation of physical processes and computation efficiency. An evaluation against two different datasets shows that TARGET can reproduce the magnitude and patterns of both air temperature and surface temperature within suburban environments. To demonstrate the utility of the model for planners and policymakers, the results from two precinct-scale heat mitigation scenarios are presented. TARGET is available to the public, and ongoing development, including a graphical user interface, is planned for future work
The urban climate of Ghent, Belgium : a case study combining a high-accuracy monitoring network with numerical simulations
As urban environments have a specific climate that poses extra challenges (e.g. increased heat stress during heat waves), gaining detailed insight into the urban climate is important. This paper presents the high-accuracy MOCCA (MOnitoring the City's Climate and Atmosphere) network, which is monitoring the urban climate of the city of Ghent since July 2016. The study illustrates the complementarity between modelling and observing the urban climate. Two different modelling approaches are used: 1 km resolution runs of the SURFEX land surface model and 100 m resolution runs of the computationally cheaper UrbClim boundary layer model. On the one hand, urban models are able to simulate the spatial variability of the urban climate. As such, these models serve as a tool to help deciding on the locations of the measurement stations. On the other hand, the MOCCA observations are used to validate the high-resolution urban model experiments for the summer (July-August-September) of 2016. Our results demonstrate that the models capture the nighttime intra-urban temperature differences, but they are not able to reproduce the observed daytime temperature differences which are determined by the micro-scale environment
Methodological Approach for the Development of a Simplified Residential Building Energy Estimation in Temperate Climate
Energy ratings and minimum requirements for thermal envelopes and heating and
air conditioning systems emerged as tools to minimize energy consumption and greenhouse gas
emissions, improve energy e ciency and promote greater transparency with regard to energy use
in buildings. In Latin America, not all countries have building energy e ciency regulations, many
of them are voluntary and more than 80% of the existing initiatives are simplified methods and are
centered in energy demand analysis and the compliance of admissible values for di erent indicators.
However, the application of these tools, even when simplified, is reduced. The main objective is
the development of a simplified calculation method for the estimation of the energy consumption
of multifamily housing buildings. To do this, an energy model was created based on the real use
and occupation of a reference building, its thermal envelope and its thermal system’s performance.
This model was simulated for 42 locations, characterized by their climatic conditions, whilst also
considering the thermal transmittance fulfilment. The correlation between energy consumption
and the climatic conditions is the base of the proposed method. The input data are seven climatic
characteristics. Due to the sociocultural context of Latin America, the proposed method is estimated
to have more possible acceptance and applications than other more complex methods, increasing the
rate of buildings with an energy assessment. The results have demonstrated a high reliability in the
prediction of the statistical models created, as the determination coe cient (R2) is nearly 1 for cooling
and heating consumption
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