Multifractal approach to urban green spaces distribution in Est-Paris
agglomeration (France) and potential benefits.
Abstract
The growth of the world’s population living in urban areas has led to
change from natural to highly dense and impermeable landscapes.
Moreover, the intensity and frequency increase of extreme events
resulting from climate change (e.g. inundations, heat waves) produce a
degradation of urban systems resilience capacity. The integration of
nature-based solutions NbS in urban spaces has been widely accepted,
like a sustainable strategy that allows to tackle these urban challenges
while building resilience and improving well-being and health. NbS are
inspired by the nature, favouring natural processes in the cities like
water infiltration or evapotranspiration (ET). Thanks to the latest, the
vegetation shadow and wind dynamics favours air temperature reduction
during heatwave events or mitigation of Urban Heat Island (UHI)
phenomenon. Consequently, the distribution of urban green spaces might
impact heat fluxes dynamics, by reducing temperature and its perception.
They may also reduce virus spreads and also the sensitivity factors to
them. Following a spatial approach, this study aims to analyse the green
space distribution across different scales in the agglomeration located
in the east of Paris (France) and various scenarios of its development.
To achieve this goal, the spatial simulation model “Fractalopolis” is
used. This allows to generate fractal urban forms using an iterative
downscaling scheme (IFS: Iterative Function System) applied to existing
large scale patterns of green areas. This work enables to analyse i) the
access of population to the nearest green area and the fractal dimension
of public urban green spaces; and ii) the impact of temperature
reduction of different land-use scenarios by coupling a multifractal
analysis of ET scaling behaviour measured at the local scale.