Abstract
Cities are the cradles of modern civilization and largest agglomerations of human activities. They experience constant internal dynamics caused by external factors like the newest COVID-19 emergency, the environmental degradation, the oil crises and unsustainable economic practices leading to social inequalities and unhealthy environments to name a few. The most severe impacts of the crisis are unfolding in cities, and Tokyo as a mega city with over 13 million residents is, at an even higher risk. Thus, explorations of how to make our cities more self-sufficient, livable and just is an emergent topic right now. Furthermore, densely populated urban areas dominated by built infrastructure and technology has led to a society that over time has separated itself and become in-dependent from nature ecosystems but faced with the above-mentioned challenges, demands on natural capital and its benefits keep increasing steadily in our urbanized planet. In the city they provide a whole array of services called urban ecosystem services that play a crucial role in sustaining important aspects of human well-being in cities such as health, security and good social relations. This research is focusing on the network of urban water streams as providers of urban ecosystem services in Setagaya-ku, Tokyo. The site is the most populous ward of Tokyo, second by area and conveniently connected to the rest of the city. Tokyo was once a city on water and everyday life was intertwined with the water network. In the Edo and Meiji period Tokyo was compared to Venice and Amsterdam in Europe. Unfortunately, the connection with water was lost due to the rapid urban growth of the city, especially after the Olympics in 1964 when many of the rivers and streams were covered by roads and now remain as hidden waterways. Based on the words from the renowned architectural historian Hidenobu Jinnai: “Water was deeply ingrained not only in industry but also entertainment in the Edo era...most places where people came together were near water. Since, we in the present have more advanced technologies, we could restore greenery and water in an appropriate way to create spaces that would be unique to a near-future Tokyo, if a goal were properly set.” There are over 100 water streams in Tokyo but many of them are covered. Today they represent a phenomenon in the urban fabric, a common sight for locals and take a significant part of the city's blue and green infrastructure grid. The route of those ancient streams is accompanied by endless kilometers of pedestrian and biking paths called "green ways". Most of the time those paths are landscaped with trees, paving stones and urban furniture and serve as connectors of different ‘machi’, meaning small towns. Coming from the hypothesis that urban life is altered trough crisis scenarios, while focusing on the use of public space, the objective is to examine the potentials of water streams as phenomenon typical to Tokyo in order to mitigate future emergent scenarios. The paper analyses the urban ecosystem services of streams that are categorized into four groups: economic, ecological, cultural and adaptive capacity term.
