GIS modeling of green roof ecosystem services to optimize green infrastructure placement and to map multifunctionality : a case study in Sydöstra staden, Uppsala, Sweden

Abstract: Green roofing has emerged as a viable option for developers and planners seeking to integrate ecosystem services into the built environment, while, at the same time, responding to the constraints posed by urban densification. Urban green infrastructure (UGI) has been placed at the core of sustainable urban planning enabling the integration of ecosystem services in urban development. UGI have proven highly useful in mitigating many of the problematic environmental aspects of cities, such as soil pollution, sealing, urban heat island effects and floods. UGIs have also been shown to significantly improve human health and well-being. Five types of green roofs are investigated and compared with one another in this thesis as they provide different ecosystem services: a water roof, an energy roof, a biodiversity roof, a food production roof and a recreation roof. This study aims to pinpoint what constitutes an optimal location and to develop a spatial methodology to identify how these various types of green roofs can be distributed and placed efficiently to take maximal advantage of the ecosystem services they provide. It also seeks to identify the multifunctionality potential of individual buildings. It uses the upcoming urban area Sydöstra staden in Uppsala, Sweden, as a case study. The district is set to undergo significant urban development and the city of Uppsala is imposing the integration sustainability innovations as a central aspect of the planning and could therefore benefit from an in-depth study on suitability of urban green roofing. The results are presented in the form of maps ranking the suitability of various buildings for optimal ecosystem service provision on a scale of 1 to 5, 1 being “not particularly effective” to 5 being “necessary”. This is done for each green roof type. The finals maps are then compared to showcase areas with the highest overall scores as highly multifunctional, and those with the lowest scores as less multifunctional. The implications of the development of such a model are discussed from an urban planning perspective and suggestions on how to integrate ecosystem services’ monetary value are also highlighted.