مفهوم برنامه ریزی یکپارچه برای شهرسازی زیرزمینی در حال ظهور: روش شهر عمیق قسمت مطالعه 1 مورد مفهوم، فرایند و کاربرد

Four underground resources have been seen as having a long-term potential to support sustainable urban development: underground space, groundwater, geomaterials and geothermal energy. Utilization of these resources proposes a new paradigm of economic development: underground urbanism. The new management approach named “Deep City Method” is put forward to aid decision-makers to integrate global potential of the urban underground into city-scale strategic planning. The research output will be presented in form of two papers each with a different focus. Part 1 aims to introduce the concept, process and initial application in Switzerland; Part 2 is devoted to show methodological insight for a new zoning policy in China and investment scenarios for project cost viability. This Part 1 paper will begin by presenting the fundamental concept of the Deep City Method, followed by a proposition for a trans-institutional planning process. The application is firstly based on a rating system to identify cities having a potential for underground development. The city of Geneva is selected for conceptual application and strategic level study. Further operational steps are required in order to generalize the concept to other cities around the world.

In 2007, the urban population around the world surpassed 50% of total habitants, among which nearly 20% live in metropolitan areas (urban areas with more than one million people).1 This emerging trend of rapid urbanization and concentration requires smarter solutions for adapting to growing needs of living space, construction land, water access, energy production and material provision. While decision makers are facing challenges to seek additional resources to meet urban demand, some emerging resources are becoming more and more attractive. Land, as the main production factor of cities, is limited, nonrenewable and scarce. Cities are transforming from agricultural traders to industrial manufacturers to service providers. Their land use planning agenda is changing from industrial land oriented planning to commercial land oriented planning to residential land oriented planning, even to mixed use planning (Kivell, 1993 and O’Sullivan, 2009). In a context of sustainable urban development, innovative spatial planning attempts to maximize land use value by mixing urban activities, linking urban mobilities, and compacting the urban fabric. While more space is needed but more land leasing is frozen, space hunting is going to a three-dimensional trend. Density generates space, but over-densification is always restricted by planning regulations. Another dimension is being stated by civil engineers, claiming that by going underground we can acquire more possibilities for construction. Emerging uses became attractive such as subway tunnels, road tunnels, buried utility lines, subterranean parking, deep storage, pedestrian pass, and large basement buildings (Magnus Bergman, 1986). Technological advancement makes these uses even more competitive (Goel et al., 2012), because going underground can mitigate surface constraints on land acquisition, from building height limits and from landscape control (Carmody and Sterling, 1993 and Golany and Ojima, 1996). Relocating space volume underground helps to equilibrate densification and revitalization. This is the first resource being used to shape underground urbanism: underground space. Water, is another critical production factor for agriculture, industry and urbanization. The use of groundwater exceeds 70% of the total water consumption in most European countries, especially for domestic drinking water use (Zektser and Everett, 2004). In the post-industrial era, quality of life dominates our residential location choice. An abundant source of drinking water has a competitive advantage for sustaining urban growth. This is the second resource offered by underground urbanism: groundwater. Energy provisioning is a challenge to modern societies. Transport and building count for more than half of the total energy demand, which is being intensified by rapid urbanization. Energy efficiency can be gained from technological innovation in transport systems and building structures. A subway, as a transport system of high efficiency, speeds up urban mobility and shortens travel time. The building sector is also undergoing continuous progress to save energy use. The ground source heat pump (GSHP) market is expanding around the world (Navigant Consulting, 2009 and IEA, 2010), making this hidden resource the third element in underground urbanism: geothermal energy ( Parriaux et al., 2004). Availability of materials is one of the main factors influencing construction industry, a mainstay sector in the urban economy. As mining areas become limited, provision of material is becoming more difficult. A recyclable material source from construction excavation sites could relieve material provision deficiency (Rochat et al., 2006). Excavation provides raw materials that may be able to aid in meeting higher demand. This is the fourth emerging resource: geomaterial.

The paper has introduced an overview of the Deep City Method and it has demonstrated an integrated planning tool for underground urbanism. Two innovative principals for urbanization strategy have been introduced in the paper: (1) Resource-based management: While the use of underground space is not a recent discovery, managing underground resources as a whole system including space, groundwater, geomaterial and geothermal energy has been ignored in the history of urbanization, this paper provides a first demonstration of the importance of managing four geo-resources in the developing stage of underground urbanization. By proposing an “Applicability score”, cities are examined through a general diagnostic, which helps to qualify and prioritize pilot cities for underground urbanism. Since data on geo-resources is usually fragmented or sometimes missing, a sound resource management is based on a foundation of existing knowledge and information. (1) Institution-based management: Success models of governing underground urbanization are summarized in Section 3. This benchmarking study helped to extract critical success factors to be referred by applicable cities. An integrated management process involved by different levels of institutions is proposed, to ensure that international experiences on strategic thinking are transferred to city level and adapted to local operational schemes. To illustrate a combination of the above-mentioned principals, a conceptual case study is demonstrated at the end. The city of Geneva is the first municipality to experience a restructuring with underground urbanism, its performance of adapting public instruments is based on the existing territorial information platform for knowledge sharing, as well as interactive coordination with existing urban planning process. These two advantages are usually not evident in those emerging growing cities. When more cities are imminent to manage the urban underground, building a comprehensive management model and planning process become critical for decision-makers in operational levels. More operational steps are required for generalizing the method to other cities around the world; this is further studied in the Part 2 paper at three scales: • Urban scale: identify key issues of underground construction and resources exploitation by academic research, digitize parameters into territorial information platform to aid urban planning and classify land qualities for land administration. • Land scale: renew land asset management based on supply capacity and demand level, by coordinating regulatory guidelines from land administrators (legal rights of land parcel) and urban planners (building codes of land parcel). • Project scale: indicate investment choices according to different uses and cost efficiency levels.