مفهوم برنامه ریزی یکپارچه برای شهرسازی زیرزمینی در حال ظهور:مطالعه 2 مورد بخش روش شهر عمیق برای تامین منابع و ارزیابی پروژه

Four underground resources have been seen as having 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. The Part 2 paper will demonstrate a comprehensive evaluation methodology for underground resources beneath the municipality of Suzhou in China, in order to formulate 3D land zoning. Strategic districts in Suzhou city of China are selected for feasibility outlook and policy instrument proposition. Finally, a new economic index “Underground cost efficiency premium” has been proposed to aid project developers to justify competitiveness of underground development.

fter the strategic level research described in the Part 1 paper, specific operational steps are performed and illustrated in this paper to specify the integrated planning process (Fig. 2 in Part 1 paper) and to make it adoptable and transferable to other cities around the world. A multi-scale approach is used for illustrating the operational feasibility of the Deep City Method. • Urban scale: the urban context of the pilot city is analyzed. Supply and demand schemes of underground space are evaluated, simulated and mapped with an integrated potential zoning indicator. Districts having a representatively high integrated potential were identified. • Land parcel scale: selected districts are analyzed with multiple criteria, including land quality, land value, and legal rights. It is at this scale that a new economic indicator “underground cost efficiency premium” is put forward, proposed as a potential specification of 3D land parcel valuation. • Project scale: project scope differs to meet particular urban needs (defined here as densification or revitalization). With variation in project scope, cost (land and construction) and benefit (direct saving in land acquisition) levels vary. This variation is defined as “rate of underground development”, which induces a series of changes in economic gain. All the macro indicators (resource capacity, municipal demand level) and micro indicators (land parcel quality, land price, project scope) were aggregated into two main criteria: development potential and economic efficiency premium. Six characteristics of urban underground asset

We have demonstrated operational steps of the integrated planning process for underground urbanism, including comprehensive underground asset supply assessment at the urban scale, in-depth investigation of strategic districts, dynamic forecast of supply and demand potential of underground space, and project appraisal of specific underground space users. A sound development agenda for the urban subsurface should be based on the strong estimation for its potential supply, which helps to ensure a sustainable exploitation process and to avoid overexploitation. To make sure that exploitation will only take place on the high quality zones, governmental intervention should be enhanced to fix planning standards of underground assets qualification (Table 4). Stage of underground development depends on demand level, which varies among districts and economic zones. Coordination of supply and demand planning is essential for underground urbanism. This paper gave a first attempt to compare capital costs between surface building and underground building, according to function, dimension, construction cost, land cost, underground space rate and subsurface quality. Cost efficiency level was estimated for various project scenarios. Economic benefits of using underground space are from reducing building footprint and reducing land acquisition costs, while ensuring floor space demand to be maintained. Over-cost can be avoided by rationalizing the development quantity of underground space according to land quality and land price. Because underground urbanism is a new planning subject, global thinking and local actions should be integrated into planning decisions. The emerging trend of underground asset management should be addressed amidst metropolitan’s strategic visions, which should be followed by multi-institutional operations to implement resources prospection, allocation, valuation and long-term supervision.