Reality check: Planning education in the African urban century

Planning in Sub-Saharan Africa owes much to the colonial legacies that inform the shape and composition of African urban spaces and places. This applies to legislation, institutional systems and planning education. In 2008, the Association of African Planning Schools AAPSs embarked on a 3-year initiative on the revitalisation of planning education in Africa, funded by the Rockefeller Foundation. The aim of the project was to propose ways through which the training of urban planners can be more responsive to the special circumstances of African urbanisation. This paper reflects on this initiative.     

A structured methodology for assessing and improving e-services in digital cities

Many cities all over the world are making large investments for the construction of big network infrastructures, in order to offer to local public organizations, businesses and citizens high speed connectivity, and on top of them useful e-services, aiming to achieve various social and economic objectives. The value generated from these costly ‘digital city’ investments is actually the value provided to the citizens and businesses by the e-services that will be developed and run on these network infrastructures. This paper proposes and validates a structured methodology for assessing and improving e-services developed in digital cities. The proposed methodology assesses the various types of value generated by an e-service, and also the relations among them, allowing a more structured evaluation, a deeper understanding of the value generation process and also identification and prioritization of the improvements that should be made in the e-service with the usually scarce resources in municipalities. This methodology is applied for the evaluation of an e-learning service developed in the Greek city of Karlovassi for young citizens, and also for the prioritization of the necessary improvements in it. The above application provided positive and encouraging evidence concerning the validity, usefulness and applicability of the proposed method.     

Can cities become self-reliant in food?

Modern cities almost exclusively rely on the import of resources to meet their daily basic needs. Food and other essential materials and goods are transported from long-distances, often across continents, which results in the emission of harmful greenhouse gasses. As more people now live in cities than rural areas and all future population growth is expected to occur in cities, the potential for local self-reliance in food for a typical post-industrial North American city was determined. Given current policies and bylaws and available area, crop yields, and human intake, three distinct scenarios were developed to determine the potential level of food self-reliance for the City of Cleveland, which has been plagued with home foreclosures and resulting vacant land, lack of access to healthy food, hunger, and obesity particularly in disadvantaged neighborhoods. Scenario I, which utilizes 80% of every vacant lot, can generate between 22% and 48% of Cleveland’s demand for fresh produce (vegetables and fruits) depending on the vegetable production practice used (conventional gardening, intensive gardening, or hydroponics), 25% of both poultry and shell eggs, and 100% of honey. Scenario II, which uses 80% of every vacant lot and 9% of every occupied residential lot, can generate between 31% and 68% of the needed fresh produce, 94% of both poultry and shell eggs, and 100% of honey. Finally, scenario III, which adds 62% of every industrial and commercial rooftop in addition to the land area used in scenario II, can meet between 46% and 100% of Cleveland’s fresh produce need, and 94% of poultry and shell eggs and 100% of honey. The three scenarios can attain overall levels of self-reliance between 4.2% and 17.7% by weight and 1.8% and 7.3% by expenditure in total food and beverage consumption, compared to the current level of 0.1% self-reliance in total food and beverage by expenditure. The analysis also reveals that the enhanced food self-reliance would result in $29 M to $115 M being retained in Cleveland annually depending upon the scenario employed. This study provides support to the hypothesis that significant levels of local self-reliance in food, the most basic need, is possible in post-industrial North American cities. It is concluded that while high levels of local self-reliance would require an active role of city governments and planners, public commitment, financial investment, and labor, the benefits to human health, the local and global environment, and the local economy and community may outweigh the cost.     

Defining and characterizing urban boundaries: A fractal analysis of theoretical cities and Belgian cities

In this paper we extract the morphological boundaries of urban agglomerations and characterize boundary shapes using eight fractal and nonfractal spatial indexes. Analyses were first performed on six archetypal theoretical cities, and then on Belgium’s 18 largest towns. The results show that: (1) the relationship between the shape of the urban boundary (fractal dimension, dendricity, and compactness) and the built morphology within the urban agglomeration (fractal dimension, proportion of buildings close to the urban boundary) is not straightforward; (2) each city is a unique combination of the morphological characteristics considered here; (3) due to their different morphological characteristics, the planning potential of Flemish and Walloon cities seems to be very different.     

高密度环境下城市微型公共空间的利用

目前城市发展迅速,以香港为代表的高密度化城市环境以及微型化城市公共空间成为普遍的城市现象。为此,我们通过对密度和知觉密度的关系研究,归纳出影响人们知觉密度感受的相关因素,并在此基础上找到现实可行的微型公共空间利用办法,使得高密度环境下有着舒适心理感受的城市公共空间得以实现。     

城中村改造探析

以具体工程为背景,通过分析城中村改造项目的特征及改造前情况,阐述了工程改造整体部署,采取的措施及一些关键环节,并总结了施工中存在的问题,最后给出了类似项目的改造建议,以指导实践。     

Coastal trapped waves in the southern Caspian Sea

Previous studies reported coastal trapped waves (CTWs) in the Caspian Sea (CS). This study deals with the generation mechanisms, the temporal and spatial variability of CTWs in this area, and their transformations during propagation from the origin to the destination using recent measurements and high-resolution numerical simulations. CTWs are observed at all stations with periods of 2–6 days after northerly storms. The Absheron Peninsula, old Sefidrud delta, and Nur coasts were identified as the CTWs prone regions. The generation of CTWs in these locations was confirmed using numerical experiments. The propagation away from the generating location of CTWs was analyzed using a representative real wind storm. In the west part of the CS, the generation mechanism of CTWs is mainly similar to the barotropic Kelvin waves; in contrast, it is similar to the continental shelf waves in the southern shelves. The results can be used to study the contribution of generated CTWs to the transport of sediment and biological materials in all large lakes.     

Rethinking urban transformation: Temporary uses for vacant land

As some cities grapple with economic decline and depopulating neighborhoods, a number of academics and professionals have focused their attention on the causes, conditions and patterns of the resultant vacant land, whereas others lay out broad programmatic, institutional, fiscal and design responses to address vacancy on site or citywide scales. We find that, regardless of condition and context, most responses advocate complex, officially sanctioned, formal programs and policies that call for or depend on implementation over several multi-year phases. While laudable in scope, we question whether “permanent” solutions are appropriate given the widely varying causes, durations, contexts and patterns of vacancy and the inability of similarly scoped government-led programs to thus far achieve intended goals or improve local quality of life. We present examples that make the case for temporary, incremental, flexible and experimental responses to urban vacant land, then conclude by outlining the potential benefits and drawbacks of this temporary use model.     

Is There Room for Families in the Inner City? Life-Stage Blenders Challenging Planning

This paper addresses the phenomenon of families returning to inner cities. With evidence from the first qualitative study done on families residing in inner-city Helsinki, it demonstrates that urban living reduces the sharp divide between life before having children and family life. Urban parents stay in the city much for the same reasons they first moved there: because they are attracted to population density, good amenities and good public transport. Living in the city enables a lifestyle where different life stages blend into each other. The paper, however, reveals that there is a lack of understanding among city planners and politicians about family needs in the inner city. By adopting a framework of the reviewed literature, the paper draws on the argument that modernist ideals on proper family living still prevail. The paper suggests that planning must acknowledge that exclusionary life stages are eroding and creating a need to facilitate multiple forms of lifestyles.