新城市时代的土地和气候变化问题

联合国人居署的预测显示,未来几十年,全球城市人口增长的95％将出现在发展中国家.城市化水平将不断提高,本世纪,亚洲和非洲城市化水平最低的地区将从农村社会转变为以城市为主的地区.到2050年,发展中国家的城市人口将达到53亿,而亚洲城市人口将占全世界城市人口的63％,即33亿人.     

Long-run urban dynamics: understanding local housing market change in London

Abstract

Recently, a literature has emerged using empirical techniques to study the evolution of international cities over many centuries; however, few studies examine long-run change within cities. Conventional models and concepts are not always appropriate and data issues make long-run neighbourhood analysis particularly problematic. This paper addresses some of these points. First, it discusses why the analysis of long-run urban change is important for modern urban policy and considers the most important concepts. Second, it constructs a novel data set at the micro level, which allows consistent comparisons of London neighbourhoods in 1881 and 2001. Third, the paper models some of the key factors that affected long-run change, including the role of housing. There is evidence that the relative social positions of local urban areas persist over time but, nevertheless, at fine spatial scales, local areas still exhibit change, arising from aggregate population dynamics, from advances in technology, and also from the effects of shocks, such as wars. In general, where small areas are considered, long-run changes are likely to be greater, because individuals are more mobile over short than long distances. Finally, the paper considers the implications for policy.     

Adaptation of interconnected infrastructures to climate change: A socio-technical systems perspective

Climate change is likely to affect how society will function in this century. Because climate change effects may be severe, a next step is to study not only the effects on natural systems, but also the effects on built infrastructure systems and, in response to anticipated effects, the adaptation of those systems. Studies that discuss interconnected infrastructures, society's backbones, in light of climate change are emerging. We apply a socio-technical systems perspective in order to gain insight into the effects of climate change on our infrastructure systems and possible adaption strategies for the coming decades. We use this perspective to collect and describe the literature on adaptation of infrastructures to climate change. We find that the analysed papers predominantly focus on specific geographic areas and that various types of impacts on and interdependencies of built socio-technical systems are recognized, not only for energy and transport, but also for water infrastructures. A missing step is the modelling of adaptation measures. Recent literature enables an exploration of strategies for adaptation, which should be expected in the coming years.     

Impacts of climate change on in-stream nitrogen in a lowland chalk stream: an appraisal of adaptation strategies

The impacts of climate change on nitrogen (N) in a lowland chalk stream are investigated using a dynamic modelling approach. The INCA-N model is used to simulate transient daily hydrology and water quality in the River Kennet using temperature and precipitation scenarios downscaled from the General Circulation Model (GCM) output for the period 1961-2100. The three GCMs (CGCM2, CSIRO and HadCM3) yield very different river flow regimes with the latter projecting significant periods of drought in the second half of the 21st century. Stream-water N concentrations increase over time as higher temperatures enhance N release from the soil, and lower river flows reduce the dilution capacity of the river. Particular problems are shown to occur following severe droughts when N mineralization is high and the subsequent breaking of the drought releases high nitrate loads into the river system. Possible strategies for reducing climate-driven N loads are explored using INCA-N. The measures include land use change or fertiliser reduction, reduction in atmospheric nitrate and ammonium deposition, and the introduction of water meadows or connected wetlands adjacent to the river. The most effective strategy is to change land use or reduce fertiliser use, followed by water meadow creation, and atmospheric pollution controls. Finally, a combined approach involving all three strategies is investigated and shown to reduce in-stream nitrate concentrations to those pre-1950s even under climate change.     

Global urban forms and local strategies of property market actors

As the neo-liberal economic and political ideology spreads, the associated mobility of capital has been driving investment in urban economies throughout the world. Local organizations and institutions have reacted in different ways to economic globalization, which may be explained by local contingencies. This article focuses on large-scale commercial complexes (e.g., shopping malls, office estates, entertainment centers) and examines these global urban forms in relation to property market dynamics and the behavior of the actors involved. Over the past decade or two, such complexes have become characteristic features of the urban landscape in countries at the periphery of advanced capitalism. For many years, the peripheral economies of Hungary, Poland, and Turkey had lagged behind advanced capitalist markets in terms of the supply of these commercial properties. By focusing on how actors in local property markets respond to dramatic changes within these booming commercial markets, this article sheds light on the institutional and organizational transformations in these countries. Furthermore, it elucidates the interaction between local and global actors—all of whom influence the materialization of these new urban forms—and the arrangements that induce them to develop the urban space. A number of projects in Budapest, Warsaw, and Istanbul have been selected to illustrate these dynamics.     

A scenario-based approach to assess Ho Chi Minh City’s urban development strategies against the impact of climate change

This paper presents an approach to quantifying current and future city-wide flood risks to Ho Chi Minh City. Here urban planning scenarios linking urban development and climate change explore the main driving forces of future risk. According to the redefined role of urban environmental planning in times of climate change, spatial planning needs to go beyond traditional planning approaches to bring together, draw upon and integrate individual policies for urban adaptation strategies for land-use planning. Our initial research results highlight that the spatiotemporal processes of urban development, together with climate change, are the central driving forces for climate-related impacts. The influence of planned urban developments to the year 2025 on future flood risk is seen to be significantly greater than that of projected sea-level rise to the year 2100. These results aid local decision making in an effort to better understand the nature of future climate change risks to the city and to identify the main driver of urban exposure.     

Simulation of synthetic climate at local scale as a mean to assess the impact of climate change on infrastructures

A global modelling approach for estimating the climate influence on corrosion activity in reinforced concrete is developed. It combines: (a) the identification of statistical properties of climates in various temperate regions, and the development of a synthetic simulator able to reproduce its dominant patterns, (b) the identification of an empirical corrosion activity model, based on the analysis of experimental data, highlighting the respective influence of temperature and humidity. Synthetic simulations combining these two models are carried out. They show the complexity of the interactions, since the influence of temperature and humidity may be adverse, and the interest to describe both random fluctuations at daily scale and at seasonal scale. They confirm that monitoring of corrosion must account for this time variability and propose a way to estimate average corrosion even with measurements which would remain limited to a short period. Synthetic simulations are also used for estimating the influence of a global warming scenario on the corrosion activity. A global increase of about 38% of corrosion activity has been estimated in response to an average temperature elevation of 3°C.     

Implications of climate variability and change on urban and human health: A review

Urban regions have exceptional attributes that leave their dwellers and properties vulnerable to climate variability and change. Global temperatures continue to change, reaching new levels almost every year for the past two decades. This review examines the scientific evidence on the impact of climate change on urban and human health. It identifies research progress and gaps in how human society may respond to, adapt to, and prepare for the related changes. However, the causes are debated; climate variability and change are real. Climate variability and disaster risk are one of the threats to human health that adversely reinforce each other. Better knowledge of the linkage between climate change, variability and extreme weather-related illness is needed and can aid strategies to reduce the vulnerability. However, from this comprehensive review, it can be suggested that increased temperature and radiation are one of the major cause of some heat-related diseases such as skin cancer, heat stroke, heart disease and diarrhea which might strongly influenced by extreme climate events. On the other hand, since the extreme heat-related illnesses occurrence is increasing alarmingly, prevention and control have become a preference in public health programs and other disease control agencies. The study also suggests that public health should be everybody's business. Furthermore, public health education concepts can improve by a broader understanding of the subjective factors that underlie risk-taking and precautionary when exposed to extreme weather events.     

A gender perspective on urban car use: A qualitative case study

This paper examines the interconnections between the motor vehicle and social change for women. It summarises some of the key gender differences and trends in travel behaviour and transport use, and outlines a response to one broad question — how are the economic, social and cultural circumstances of the 1990s influencing women's transport patterns and car use?     

Simulating the effects of climate change,economic and urban planning scenarios on urban runoff patterns of a metropolitan region

Urban development and climate change are expected to have significant effects on urban stormwater runoff. In this study, the Dynamic Urban Water Simulation Model (DUWSiM) is applied to Dublin, Ireland, to explore urban runoff patterns under varying urban growth and climate scenarios. Results show that annual urban runoff could decrease by 3.0% from climate change and monthly runoff could increase by 30% in winter and decrease by 28% in summer. Results also indicate that urban growth could increase annual runoff by up to 15%. The combined effect of climatic and land-use change generated runoff may potentially increase annual totals from between 2.9% to 21%. Monthly changes in runoff totals could increase by up to 57%. Accommodating these variations in runoff between the scenarios, flexible decentralised systems such as green roofs and pervious pavements, have a vital role in increasing the adaptability and long term sustainability of water infrastructure.     

Central‐local relations in Sweden and Australia: Power,responsibility and territorial equity in comparative perspective

Different governmental arrangements have varying impacts on the equity of provision of public services. But these impacts are modified by the cultural‐political traditions of nations. In this paper we compare central‐local relations in Sweden and Australia in broad qualitative terms. We explore the concept of ‘territorial equity’ and employ a resource model of government power to describe central‐local relations in the two countries. In any society the relative emphasis given to the opposing distributive principles of the governmental and market spheres—equity and efficiency—will greatly affect outcomes. We discuss the different significant variables contributing to a degree of equality in service provision in the two countries and foreshadow changes ahead, with varying capacity in the two countries to resist moves towards greater inequality in the provision of essential public services.