Densification Of Cities Research Articles

Local Hedonic House-Price Modelling for Urban Planners: Advantages of Using Local Regression Techniques

Hedonic house-price models have long been used in urban studies to investigate important factors characterizing cities (eg, the demand for amenities or housing submarkets). Traditionally, the formulation of hedonic models has been solved using global spatial econometric techniques. The development of local regression methods brought new insights into urban planning as the relationships between house prices and their determinants can be estimated locally and therefore mapped across space. Such maps provide planners and policy makers with valuable location-specific information to support their decision-making processes. A feature that is frequently overlooked when performing spatial local analysis is testing the statistical significance of local parameter estimates over space. This can be done by mapping the t-value of parameter estimates ( t-surfaces). In this study we propose the use of a mixed geographically weighted regression (mixed-GWR) technique to estimate a hedonic house-price model in Zurich. Mixed-GWR is an extended version of GWR by which some parameters are allowed to vary over space, while others remained fixed. To obtain spatially explicit results in a more meaningful way, we propose the use of t-surfaces to explore the statistical significance of selected local parameter estimates over space. We also follow the Bonferroni correction to overcome the problem of multiple hypothesis testing in local regression modelling. Results reveal interesting patterns in the spatial variability of local estimates for planners. For instance, areas are identified over which public policies such as house taxing have little or no effect on house pricing. Similarly, economic distortions in the housing market can be examined through the variability of residents' willingness to pay for larger dwellings. Also, urban development processes such as densification of cities can be supported by spatially exploring relevant socioeconomic variables.

MUSE: An Open Urban Management Decision Support System

Abstract This paper describes a decision support tool for urban planners. Numerous research studies show that energy consumed and produced in cities can be related to its morphology. Yet, the urban energy paradox is defined as follows: on the one hand, the densification of cities reduces transportation and buildings consumptions. On the other hand, this densification has a negative impact on urban microclimate and renewable energies potential. The goal of this work is to develop a decision support system for urban planners faced with urban energy paradox. Our research is based on a previous work developed by Luc Adolphe et al. in the SAGACites project. This research led to the development of the geographic information system (GIS) platform called MORPHOLOGIC, which, among other things, evaluates the energy consumption of city blocks. Our goal is to add new features in MORPHOLOGIC: one of them calculates solar potential (photovoltaic and thermal), using a simplified model of shadows. The new version of MORPHOLOGIC called MUSE, based on the open source GIS called OrbisGis developed by the IRSTV institute, will allow urban planners to evaluate the best urban form to reduce GHG emissions.

Do Public Transport Improvements Increase Agglomeration Economies? A Review of Literature and an Agenda for Research

Public transport improvements may increase economic productivity if they enable the growth and densification of cities, downtowns, or industrial clusters and thereby increase external agglomeration economies. It has been argued that the potential agglomeration benefits are large; if so, understanding them better would be useful in making funding decisions about public transport improvements. We reviewed theoretical and empirical literature on agglomeration as well as a small number of articles on transportation's role in agglomeration. The theoretical literature is useful in understanding possible avenues by which transportation improvements might affect agglomeration, although there is little discussion of public transport specifically. Relevant empirical studies tend to focus on metropolitan regions and use a generalized measure of transportation cost. But public transport impacts on agglomeration are likely to be different from road investment impacts. We identified several ways of conducting research building on this literature that would help evaluate the agglomeration impacts of public transport proposals: tracing the links between transport, agglomeration, and productivity; better motivating research using theories of agglomeration mechanisms; taking scale and redistribution into account; exploring the functional form of agglomeration economies; accounting for endogeneity in model structure; and considering development context.

The effects of Seoul’s greenbelt on the spatial distribution of population and employment, and on the real estate market

This paper examines the effects of Seoul’s greenbelt on the distribution of population and employment, and on the real estate market, under the assumption of the complete relaxation of the greenbelt using the random utility-based metropolitan input–output model with an endogenous land market for the Seoul metropolitan area. Simulation results show two important consequences of the greenbelt release. First, the greenbelt release would attract more residents and jobs into greenbelt zones and reduce the population and number of firms in both the central city and outer sides of the greenbelt, thereby implying the reduction of inner city densification and of development beyond the greenbelt. Second, both residential and nonresidential space rents would have declined for the whole metropolitan area from 0.4 to 13.7% had the greenbelt been completely released in 2006, thereby indicating that Seoul’s greenbelt made a contribution to raising space rents by limiting land supply.

Can River Ferries Deliver Smart Growth?

Brisbane, Australia, introduced catamaran river ferries (CityCats) in 1996 to help reorient the city to its river, to encourage inner city densification, and to spur changes in attitudes toward public transportation. The Brisbane ferry network has grown significantly over the past 14 years and is now a key commuter and tourist transport mode that in 2008 carried 6.28 million passengers, servicing 23 locations throughout the city. Two ferry terminals will be built during the coming years, with private land developers contributing partial funding for one terminal and total funding for the other. Although CityCats seemingly had been used successfully to achieve transit- (or ferry-) oriented development (TOD), a review of key transport and land use planning policy documents found that CityCats had not been used strategically to achieve TOD. This finding suggested that the relationship between the ferries and urban development had been more pragmatic and coincidental, whereas broader strategic planning had been focused more on general smart growth principles and transport planning, and TOD policy had mainly centered on rail and buses. Developments that surround the two new ferry terminals will not be dependent on the ferries for their success; their riverfront location alone ensures success. As with previous nodes on the CityCat network, the primary motivation for developer funding of ferry terminals was as a marketing tool to increase sales.

Biochemical characterization of urban soil profiles from Stuttgart, Germany

The knowledge of biochemical properties of urban soils can help to understand nutrient cycling in urban areas and provide a database for urban soil management. Soil samples were taken from 10 soil profiles in the city of Stuttgart, Germany, differing in land use—from an essentially undisturbed garden area to highly disturbed high-density and railway areas. A variety of soil biotic (microbial biomass, enzyme activities) and abiotic properties (total organic C, elemental C, total N) were measured up to 1.9 m depth. Soil organic matter was frequently enriched in the subsoil. Microbial biomass in the top horizons ranged from 0.17 to 1.64 g C kg −1, and from 0.01 to 0.30 g N kg −1, respectively. The deepest soil horizon at 170–190 cm, however, contained 0.12 g C kg −1 and 0.05 kg N kg −1 in the microbial biomass. In general, arylsulphatase and urease activity decreased with depth but in three profiles potentially mineralizable N in the deepest horizons was higher than in soil layers directly overlying. In deeply modified urban soils, subsoil beside topsoil properties have to be included in the evaluation of soil quality. This knowledge is essential because consumption of natural soils for housing and traffic has to be reduced by promoting inner city densification.

Defining spatial concepts toward an African urban system

Urban society in South Africa has two major cultural streams, overlaid by international ‘norms’. Historically, colonial settlement in South Africa (as elsewhere) imposed a European, metropolitan culture of cities. This included exotic flora and fauna, but most important a very different view about space, and division and ownership of land. Urban ‘racial’ demography is increasingly reflective of the country as a whole. Rapid urbanisation is overlaid by serious social and physical pathologies and widespread alienation. Proactive central city densification, as a viable solution, requires particular sensitivity to peoples' psychical and cultural values. This calls into question the lack of enquiry in this regard. ‘Normative’ planning prevails, and any synthesised urban system, responsive to African urban society has not been conceptualised. Cities are an invention of society, of what that society believes itself to be, in space and time. We experience cities, primarily through our ‘sense’ of space; ‘All our consciousness is bound in space’ (Kant). We have complex ways in which space is both felt and imagined, and while some spatial imagination is universal and ‘hard wired’ (increasingly verifiable through neural science), more is learnt, growing in specific social, cultural and physical environments. Beyond that, a ‘world view’ encompasses our whole self, as social being and individual, both physically and metaphysically. European cultural tradition is never free of ‘ordering devices’, refined, in modern history during the Enlightenment. It is further infused by doubt; validation is through material, aesthetic experience. African culture validates itself through personal and humanist values. Certain confluences occur where Greco Roman origins of Western European culture replicate African values. The potential exists to synthesise compatible urban spatial systems. Human spatial sensibilities, and the way in which African and European cultures perceive this are examined to this end.