From Compact City to Smart City： A Sustainability Science ＆ Synergy Perspective

This brief conceptual paper contributes a sustainability theoretic perspective of an urbanization paradigm known as Compact City. Compact City is an urban planning and development concept which promotes relatively high population density associated with an integrated and mixed-use land district. It is enabled by transit-oriented development and results in low transport-related energy consumption and reduced the GHG （Greenhouse Gases） pollution. Compact City conserves the natural capital of land mass and subscribes to the strong sustainability ethics. ICT （Information and Communications Technology） could be deployed to optimize the Compact City operations by first tackling some of the development problems associated with Compact City and also unleashing new urban innovations and functionalities to achieve sustainable urbanization. The paper suggests and elucidates several general systemic synergies archetypes such as co-benefits, cascading, ICT infrastructure reuse, etc., which could be leveraged to facilitate the emergence of compact green smart and resilient city. These archetypes are solutions to the Compact City paradigm thus conductive to the development ofa Sustainability Science of Compact City.

URBAN FORM FOR A SUSTAINABLE FUTURE: How Sustainable Is Distributed Working in the Networked City?

Our understanding of urban form depends on how we perceive the city.Much of the literature on urban form(1)has focused on the pre-industrial and industrial city,celebrating its compact form,contiguous functions and single dominant centre.More recently writings by Castels(2)and Soja(3)have described the dispersed,city of the post industrial era.This networked city triggered by the freedom afforded by the new technology(4)has exposed a new dimension to urban form.The model of the compact city advocated by those such as Lord Rogers Task Force for delivering the Urban Renaissance(5)is being questioned(6)and a new model of“high density nodes,in a high density landscape resulting in a low density city,”as in the Deltametropolis,described by Dirk Frieling(7).Compactness,cramming more development into the city and making public spaces of a higher density and quality,Rogers and Burdett argue(8)will make“urban living attractive,ecologically sustainable,economically strong and socially inclusive.”The alternative argument is that the economic success of cities is reliant on the networking of resources across a metropolitan region.Echenique argues(9)that cities disperse in their search for mobility and space.“Mobility increases the effi ciency of households and fi rms which in turn generates more income and profi ts.As income increases,so does the demand for space,residential and commercial alike.”Sustainability has become the current banner of political correctness.Sustainability however is a slippery word.It is easy to focus on one aspect and lose the value of its holistic meaning.For many architects“green buildings”equals a sustainable future.However,clever design solutions single-mindedly pursued with little regard to the wider exploration of the potential environmental savings that may be achieved through organisational innovation are only half the answer.A holistic approach concerned with both building and organisational design and focused on“lean thinking”(10)could make considerable inroads into reducing the ecological footprint.The paper draws on DEGW’s experience of advising major corporations and cities on strategies for managing the process of intensifi cation and change(11).It explores how major improvements might be gained in meeting our goals for the sustainable city through reconsidering the way we work and allocate space.The underlying proposition is that technology has offered us new opportunities which have changed our paradigm of living and working.This in turn has provided us with a new perception of the city,as a distributed series of high density centres connected by good public and private transport,within a low density landscape.The paper argues that considerable improvements in workplace sustainability can be achieved by applying a holistic approach.These may include a combination of strategies,from rethinking the organisation of work processes and the locations and time work is undertaken,to reducing the need for resources by a more intensive use of land and fl oor space.Disjointed,dispersed“urban sprawl”can be wasteful.The alternative emerging urban form is a planned,dispersed,“networked”city with well integrated public and private transport that yields greater choice of location and lifestyles so supporting social,economic and environmental sustainability.

Urban Regeneration Challenge： The Case of Avenidas Novas District in Lisbon

This paper aims at presenting the guidelines for an urban regeneration strategy in Lisbon, having in account the principles of urbanity, density, livability and social and territorial cohesion. The case study will be Avenidas Novas district, in Lisbon, Portugal, as it is a paradigmatic example of a central area which coexists with dynamism and decadence. The development model for Avenidas Novas was inspired on French boulevards and was planned to be the modem face of a medium to high social class population, as it was until 1940s. Today, as a consequence of further developments which corrupted the first principles and concept, its urban fabric is becoming less coherent and adequate to the needs of the population who works and lives there. From an analysis to the various components of the urban fabric, the paper will identify the major problems that are happening on the site, related to accessibility, mobility and functional diversity. Once understanding the impacts of an unsustainable territory management and urban design, the goal is to develop the principles for a creative urban regeneration strategy for Avenidas Novas district. The study will be based on the theoretical issues of the compact city and walkable distances in order to develop quantifying parameters of urban quality and to promote human scale public spaces and territorial cohesion on an urban environment.

GLOBAL AWARENESS,FUTURE CITY DESIGN AND DECISION MAKING

Our world has been changing at an exponential rate. As a result of this rapid growth, we will be forced to make changes in not only the way we live in the environment but also in the environment itself such as designing the cities of the future to be in greater harmony with the increasing population and growing complexity. The paper contains both reflections on global awareness and comprehensive criteria and their priorities for choosing the most desirable city.

The compactness of spatial structure in Chinese cities:measurement,clustering patterns and influencing factors

Rapid urbanization in China has led to an excessive urban expansion of built-up areas,which makes quantitative research on compact city important.We adopted density and the degree of mixed land use to measure the compactness of 160 Chinese cities.Spatial autocorrelation analysis was performed to identify spatial clustering patterns,and the relationships between compactness and five variables were explored through regression models.The result shows that in nearly half of the cases,the calculated values of two indices are less than the average.The high or low values of density and the degree of mixed land use tend to be spatially clustered.The hot spot regions of density and the degree of mixed land use lie mainly in the south of China,while the north present as cold spots or the insignificant regions.Urban compactness can be affected by multifaceted factors and the relationships between compactness and five variables are not consistent throughout the areas of analysis.The GWR model can identify this phenomenon and provides a better fit than the OLS model.This study proposed a new approach to measure the compactness,and the results of GWR analysis can conducive to appropriate policy-making based on different local conditions.

Method for the proposal and evaluation of urban structures for compact cities using an expert system

The world population is continually increasing, but the Japanese population is decreasing. By 2050, the Japanese population is calculated to be close to 100 million people, and by 2060, 40% of the Japanese are estimated to be aged 65 years or more. Data show an increase in the declining birth and aging rates of the population. The development of high-concentration urban structures will be needed to solve such problems. However, a detailed vision of the future is yet to be clarified and in the process of consideration. In this study, we developed an instrument called ＂Population Migration Tool,＂ which is based on plural planning and policy, after we formed a future population distribution model. In addition, We also established a high- concentration urban structure model with this tool with the aim of considering the kind of urban structure local cities should target in the future.

Occurrence factors of large vacant lots in central districts and their utilization by local governments in Japan

In Japan, focal cities experience a number of probtems retated to deterioration of residentiat environment, quality of public service, and vitalization of commercial rand. SpecificaLLy, the presence of Large vacant tots behind sizable stores, office buildings, hospitals, and factories devitatize urban activity and its Landscape. Many local cities are seeking to actuatize a sustainable compact city with an integrated poputation, commerce, traffic and other pubLic services in ways that promote a tow carbon and energy-conserving society. Against the backdrop of these issues, this study examines the occurrence of large vacant lots and their utilization by tocat governments in Japan based on a questionnaire and fietd survey. It highlights severat cases in which a Large vacant tot is used to forward the development of a compact city by a tocat government.

Proliferation of district heating using local energy resources through strategic building-stock management： A case study in Fukushima, Japan

District heating systems using cogeneration technology and renewable resources are considered as an effective approach to resources conservation and reduction of greenhouse gas （GHG） emissions. However, wide- spread aging and depopulation problems, as well as the popularization of energy-saving technologies in buildings, are estimated to greatly decrease energy consumption, leading to inefficiency in district heating and barriers to technology proliferation. From a long-term perspective, land use changes, especially the progression of compact city plans, have the potential to offset the decrement in energy consumption that maintains the efficiency of district heating systems. An integrated model is developed in this paper based on building cohort analysis to evaluate the economic feasibility and environmental impact of introdu- cing district heating systems to a long-term compact city plan. As applied to a case in the Soma Region of Fukushima, Japan, potential migration from the suburbs to the central station districts is simulated, where district heating based on gas-fired cogeneration is expected to be introduced. The results indicate that guided migration to produce concentrated centers of population can substan- tially increase the heat demand density, which supports a wider application of district heating systems and better low-carbon performance. These results are further dis- cussed in relation to technology innovation and related policies. It is concluded that policies related to urban land use planning and energy management should be integrated and quantitatively evaluated over the long-term with the aim of supporting urban low-carbon sustainable develop- ment.

Building three-dimensional pedestrian networks in cities

With the rapid growth of automobile transport over the last century,conflicts between automobile and pedestrian transport have been viewed as a major concern in urban and transport planning.Elevated and underground pedestrian networks,which compensate for sidewalks at the street level and provide alternative options for pedestrians,have been developed in many cities.Elevated and underground pedestrian networks offer pedestrian–car separation in a vertical dimension and efficient connections between transit services and cities for subway passengers.This study aims to provide a balanced understanding of the development of underground pedestrian networks and propose supportive strategies for decision makers,planners,and designers concerned with the future implementation of underground pedestrian networks and the building of three-dimensional pedestrian networks in cities.The study applied textual analysis to examine the topic.The study indicated that three-dimensional pedestrian systems were developed based on historical precedents.It highlighted important considerations(such as dense cities,disaster mitigation and protection,and urban functions)in developing underground pedestrian networks in cities.Furthermore,it discussed significant aspects in planning and designing such networks,including safety,ease of orientation,and convenience.The paper also discussed policy implications in developing underground pedestrian networks and the building of three-dimensional pedestrian networks in cities.

Urban land expansion and its driving factors of mountain cities in China during 1990–2015

Land expansion of mountain cities in China is not systematically studied yet. This study identified 55 major mountain cities at and above prefecture level, and analyzed the land expansion characteristics and driving forces, based on visually interpreted data from TM images in 1990, 2000, 2010 and 2015. From 1990 to 2015, total built-up land area of the mountain cities increased by 3.87 times, 5.56% per year. The urban land growth was apparently accelerated after 2000, from 4.35% per year during 1990-2000 increased to 6.47% during 2000-2010 and 6.2% during 2010-2015. Compared to the urban population growth, the urban land expansion rate was 44% higher. As a result, the urban land area per capita increased, but it was still within the government control target, and also was much lower than the average of all cities in China. Urban development policy, changes to administrative divisions, GDP and population growth, and road construction were identified as the major driving forces of land expansion. Terrain conditions were not found a relevance to the urban land expansion rate during 1990-2015, but had a significant impact on the layout and shape, and also probably on the urban land efficiency.