Reducing Heat Stress, The Impact of Different Vegetation Types

Case study Oosterdokskade, Amsterdam

Rapid urbanisation has led to a significant increase in urban sprawl, posing a challenge to traditional expansion methods. Cities are exploring alternative solutions such as high-rise buildings and greater use of underground space, but this introduces the 'Density Paradox', where heat cannot escape, leading to rising temperatures in the urban environment. This heat stress is becoming more frequent and widespread, particularly in densely populated places, and leads to increased heat-related mortality rates. This thesis focuses on urban public spaces with limited subsurface space and mitigating heat stress and answers the question: “How can urban public spaces with limited subsurface space be effectively greened to optimise the cooling effect to mitigate heat stress in Amsterdam and how can it be implemented at the Oosterdokskade?”. Green spaces play a crucial role in enhancing liveability and mitigating the UHI-effect. This research analysed the effects of different vegetation types, trees, shrubs and grass, respectively, on reducing heat stress in public spaces with limited subsurface area in Amsterdam. Interviews were conducted to identify the challenges encountered in implementing urban green initiatives and the strategies employed to tackle these obstacles. ENVI-met (version 5.5.1) was used to create a modelled result to investigate the potential cooling effect of the varied vegetation types. The results showed that the possibility to implement a green infrastructure could be endless, as long as the right approach is used. This is of importance in order for the vegetation to fully thrive. Only then vegetation can effectively cool the area. In the case of the Oosterdokskade, the subsurface is about 1.5m deep, but trees can thrive, due to the use of Boombunkers. The results show that by placing trees on the Oosterdokskade, the heat stress can be reduced by almost 14 degrees. This reduction can substantially improve the living environment and prevent heat-related health issues. This study also found that implementing grass and shrubs barely have an impact on reducing heat stress. Furthermore, this study also discovered that implementing a combination of different vegetation types did not notably affect the heat stress.