Multifunctionality is seen as one of the key benefits delivered by sustainable urban drainage systems (SUDS). It has been promoted by both scientific research and practical guidelines. However, interrelations between different benefits are vaguely defined, thus highlighting a lack of knowledge on ways they could be promoted in the actual design process. In this research, multifunctionality has been studied with the help of scenario analysis. Three stormwater scenarios involving different range of SUDS elements have been designed for the case area of Kirstinpuisto in the city of Turku, Finland. Thereafter, the alternative design scenarios have been assessed with four criteria related to multifunctionality (water quantity, water quality, amenity, and biodiversity). The results showed that multifunctionality could be analyzed in the design phase itself, and thus provided knowingly. However, assessing amenity and biodiversity values is more complex and in addition, we still lack proper methods. As the four criteria have mutual interconnections, multifunctionality should be considered during the landscape architectural design, or else we could likely lose some benefits related to multifunctionality. This reinforces emerging understanding that an interdisciplinary approach is needed to combine ecological comprehension together with the system thinking into SUDS design, locating them not as individual elements or as a part of the treatment train, but in connection with wider social ecological framework of urban landscape.

This study aims to explore the measurement of potential synergies between water management objectives and other ecosystem services generated by Nature-Based Solutions (NBS) in the context of urban planning. The research also investigates the comparative benefits of two analytical methods, Storm Water Management Model (SWMM) and green area factor for districts (GAFD). The study employs Malmi district in Helsinki, Finland, as a case study, examining five distinct NBS scenarios with varying degrees of integration. The results affirm that NBS can indeed enhance ecosystem services provision and stormwater management. The comparative analysis of the two methods, reveals that scenarios with high green factors exhibit effective flood risk reduction, while those with low green factors struggle to manage water, emphasizing the importance of balancing green and built elements in urban planning for optimal flood risk reduction. Furthermore, the study underscores the advantages of the two methods: GAFD offers simplicity and lower expertise requirements, generating valuable insights into ecosystem services, while SWMM provides precise stormwater management data. The findings emphasize the significance of diverse NBS combinations that harness the multifunctional aspects of green infrastructure, highlighting the need for integrated urban planning. The utilization of GAFD analysis provides a comprehensive districtwide perspective in a flexible manner, thereby improving the comprehension of the interconnected nature of urban green spaces. Highlights: Nature-based solutions (NBS) support urban stormwater management in infill areas. Green Area Factor for Districts (GAFD) is a practical tool to compare NBS options. GAFD and SWMM modeling results on stormwaters are comparable for common rain events. NBS size, quality and diversity reduce peak flows and enhance ecosystem services. Assessment of scenarios with the GAFD tool helps to identify multiple benefits of NBS.

Kaupunkisuunnittelun biodiversiteettikäänne haastaa perinteiset ihmiskeskeiset lähestymistavat, korostaen symbioottisemman luontosuhteen merkitystä kestävän kehityksen osana. Tutkimuksessa tarkastellaan suomalaisen kaupunkisuunnittelun tämänhetkisiä käytäntöjä. Kyselyiden ja haastatteluiden kautta ilmenee, että luonnon monimuotoisuus on noussut keskeiseksi teemaksi kaupunkisuunnittelussa. Vaikka kestävyystyössä on edistytty, strategiset ja käytännön ristiriidat ekologisten ja muiden suunnittelutavoitteiden välillä vaativat edelleen ratkaisua. Jotta käänne biodiversiteetin tukemiseen voi todella tapahtua, tarvitaan syvällisempää arvokeskustelua ja vahvempaa strategista ja numeerista ohjausta suunnitteluprosessissa.