Transforming the city region Arnhem Nijmegen into a climate proof region
The activities of the City of Arnhem within the Future Cities project are implemented on behalf of the City Region Arnhem Nijmegen.
The focus is on adapting the 'city-environments' to the climate change in order to keep the city liveable to work, live and recreate. Reducing the Urban Heat Island effect, improving the quality of the air, reducing the demand on energy and sustainable water management are the main items. The keywords are green, water, energy supply and urban morphology.
The Urban Heat Island (UHI) effect
An urban heat island (UHI) is a built-up area that is significantly warmer than its surrounding rural areas. Three to four degrees is no exception. The main cause of the urban heat island effect is thermal radiation, due to the modification of the land surface by urban development. Tall buildings provide multiple surfaces for the reflection and absorption of sunlight, increasing the efficiency with which urban areas are heated. Other causes of the UHI-effect are the lack of evapotranspiration, due to the lack of vegetation and stony environments, in urban areas.
The UHI-study within the Future Cities project
Within the Future Cities project a regional climate study will be implemented. The aim of the study is to develop:
- a method to jugde the climate proofness of an area on three levels: the City Region region itself, the compact city and a specific (project)area.
- a toolbox of measures to reduce the effects of the climate change (adaptation) and contribute to the reduction of the climate change (mitigation).
In the study the focus is on four components:
- the green structure, including dust and the CO2-balance. Green structures - such as green roofs, vertical green and "surface green" (trees, parks) - have a positive effect on the temperature in the city, the air quality and rainwater storage. Besides this green structures also influence the temperature (climate) within buildings.
- the water/humidity balance. Water structures - such as ponds, water courses, rivers but also storage of water on green roofs - have a cooling-down effect on the city temperature. Green structures have influence the humidity balance.
- the heat/energy balance: what means of energy supply are used in the city and contribute to the heating up of the city and CO2-balance.
- the landscape or morphology. Both natural and man-made structures have effect on the temperature of an area. The urban structure of buildings and public space, size and shapes of buildings, influence both the heating up of the city as the cooling down of the city/urban areas. Furthermore the location and orientation of tall building have influence on the cooling air currents in the city.
The study will be set up in four stages:
- investigation stage
- research stage (workshops)
- testing stage
- building stage
