Showing papers on "Urban climate published in 2008"
TL;DR: In this paper, a review of the literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures and concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment.
Abstract: Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generated from urban structures, as they consume and re-radiate solar radiations, and from the anthropogenic heat sources are the main causes of UHI. The two heat sources increase the temperatures of an urban area as compared to its surroundings, which is known as Urban Heat Island Intensity (UHII). The problem is even worse in cities or metropolises with large population and extensive economic activities. The estimated three billion people living in the urban areas in the world are directly exposed to the problem, which will be increased significantly in the near future. Due to the severity of the problem, vast research effort has been dedicated and a wide range of literature is available for the subject. The literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures. This study was carried out to review and summarize this research area through an investigation of the most important feature of UHI. It was concluded that the heat re-radiated by the urban structures plays the most important role which should be investigated in details to study urban heating especially the UHI. It was also concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment.
1,160 citations
TL;DR: In this paper, the authors present a conceptual framework linking urban form to residential energy use via three causal pathways: electric transmission and distribution losses, energy requirements of different housing stocks, and space heating and cooling requirements associated with urban heat islands.
Abstract: While the impact of urban form on transportation energy use has been studied extensively, its impact on residential energy use has not. This article presents a conceptual framework linking urban form to residential energy use via three causal pathways: electric transmission and distribution losses, energy requirements of different housing stocks, and space heating and cooling requirements associated with urban heat islands. Two of the three can be analyzed with available national data. After we control for other influences, residents of sprawling counties are more likely to live in single-family detached houses than otherwise comparable residents of compact counties and also more likely to live in big houses. Both lead to higher residential energy use. Because of the urban heat island effect, residents of sprawling counties across the nation on average pay a small residential energy penalty relative to residents of compact counties. Implications for urban planning are explored.
596 citations
TL;DR: Most cities showed a U-shaped temperature-mortality relationship, with clear evidence of increasing death rates at colder temperatures in all cities except Ljubljana, Salvador and Delhi and with increasing heat in all city except Chiang Mai and Cape Town.
Abstract: BACKGROUND: This study describes heat- and cold-related mortality in 12 urban populations in low- and middle-income countries, thereby extending knowledge of how diverse populations, in non-OECD countries, respond to temperature extremes. METHODS: The cities were: Delhi, Monterrey, Mexico City, Chiang Mai, Bangkok, Salvador, Sao Paulo, Santiago, Cape Town, Ljubljana, Bucharest and Sofia. For each city, daily mortality was examined in relation to ambient temperature using autoregressive Poisson models (2- to 5-year series) adjusted for season, relative humidity, air pollution, day of week and public holidays. RESULTS: Most cities showed a U-shaped temperature-mortality relationship, with clear evidence of increasing death rates at colder temperatures in all cities except Ljubljana, Salvador and Delhi and with increasing heat in all cities except Chiang Mai and Cape Town. Estimates of the temperature threshold below which cold-related mortality began to increase ranged from 15 degrees C to 29 degrees C; the threshold for heat-related deaths ranged from 16 degrees C to 31 degrees C. Heat thresholds were generally higher in cities with warmer climates, while cold thresholds were unrelated to climate. CONCLUSIONS: Urban populations, in diverse geographic settings, experience increases in mortality due to both high and low temperatures. The effects of heat and cold vary depending on climate and non-climate factors such as the population disease profile and age structure. Although such populations will undergo some adaptation to increasing temperatures, many are likely to have substantial vulnerability to climate change. Additional research is needed to elucidate vulnerability within populations. Language: en
569 citations
TL;DR: Overall, there is no evidence that the level of urbanization affects the rate of economic growth, which weaken the rationale for either encouraging or discouraging urbanization as part of a strategy for economic growth.
Abstract: The proportion of a country's population living in urban areas is highly correlated with its level of income. Urban areas offer economies of scale and richer market structures, and there is strong evidence that workers in urban areas are individually more productive, and earn more, than rural workers. However, rapid urbanization is also associated with crowding, environmental degradation, and other impediments to productivity. Overall, we find no evidence that the level of urbanization affects the rate of economic growth. Our findings weaken the rationale for either encouraging or discouraging urbanization as part of a strategy for economic growth.
473 citations
TL;DR: In this paper, the authors examine the recent process of urban growth against the background of urban compactness and extreme densification represented by the Barcelona Metropolitan Region (BMR) and conclude that polycentric metropolitan areas such as the BMR may be more adjusted to absorb the negative effects of dispersion than monocentric areas.
409 citations
Book•
01 Jan 2008
TL;DR: The early history of urban ecology can be traced back to the early 20th century, when the first urban ecology research was carried out in the UK as discussed by the authors, where the authors focused on the effects of urbanization on the ecology of the environment.
Abstract: Urbanization and Human Domination of Earth.- Human Domination of Earth's Ecosystems.- Humans as the World's Greatest Evolutionary Force.- Urbanization.- Urban Ecology as an Interdisciplinary Field: Differences in the use of "Urban" Between the Social and Natural Sciences.- Conceptual Foundations of Urban Ecology.- The Growth of the City: An Introduction to a Research Project.- On the Early History of Urban Ecology in Europe.- Urban Ecological Systems: Linking Terrestrial Ecological, Physical, and Socioeconomic Components of Metropolitan Areas.- Integrated Approaches to Long-Term Studies of Urban Ecological Systems.- Integrating Humans into Ecology: Opportunities and Challenges for Studying Urban Ecosystems.- The Atmosphere, Hydrosphere, and Pedosphere.- Sealing of Soils.- Producing and Consuming Chemicals: The Moral Economy of the American Lawn.- Streams in the Urban Landscape.- The Urban Climate - Basic and Applied Aspects.- Global Warming and the Urban Heat Island.- A Retrospective Assessment of Mortality from the London Smog Episode of 1952: The Role of Influenza and Pollution.- Heat Waves, Urban Climate and Human Health.- The Biosphere.- The City as a Subject for Ecological Research.- Ecosystem Processes Along an Urban-to-Rural Gradient.- House Sparrows Rapid Evolution of Races in North America.- On the Role of Alien Species in Urban Flora and Vegetation.- Socioeconomics Drive Urban Plant Diversity.- Fauna of the Big City - Estimating Species Richness and Abundance in Warsaw Poland.- Island Biogeography for an Urbanizing World How Extinction and Colonization May Determine Biological Diversity in Human-Dominated Landscapes.- A Long Term Survey of the Avifauna in an Urban Park.- Biodiversity in the Argentinean Rolling Pampa Ecoregion: Changes Caused by Agriculture and Urbanisation.- Does Differential Access to Protein Influence Differences in Timing of Breeding of Florida Scrub-Jays (Aphelocoma coerulescens) in Suburban and Wildland Habitats?.- Creating a Homogeneous Avifauna.- Towards a Mechanistic Understanding of Urbanization's Impacts on Fish.- Bat Activity in an Urban Landscape: Patterns at the Landscape and Microhabitat Scale.- Urbanization and Spider Diversity: Influences of Human Modification of Habitat Structure and Productivity.- The Anthroposphere: Human Dimensions.- Social Science Concepts and Frameworks for Understanding Urban Ecosystems.- The Iceberg and the Titanic: Human Economic Behavior in Ecological Models.- Forecasting Demand for Urban Land.- Characteristics, Causes, and Effects of Sprawl: A Literature Review.- Urban Ecological Footprints: Why Cities Cannot be Sustainable-and Why They are a Key to Sustainability.- Health, Supportive Environments, and the Reasonable Person Model.- Relationship Between Urban Sprawl and Physical Activity, Obesity, and Morbidity.- Megacities as Global Risk Areas.- Why Is Understanding Urban Ecosystems Important to People Concerned About Environmental Justice?.- The Anthroposphere: Planning and Policy.- The Struggle to Govern the Commons.- Modeling the Urban Ecosystem: A Conceptual Framework.- Scientific, Institutional, and Individual Constraints on Restoring Puget Sound Rivers.- Toward Ecosystem Management: Shifts in the Core and the Context of Urban Forest Ecology.- What Is the Form of a City, and How Is It Made?.- What Should an Ideal City Look Like from an Ecological View? - Ecological Demands on the Future City.- Land Use Planning and Wildlife Maintenance.- Terrestrial Nature Reserve Design at the Urban/Rural Interface.- Restoration of Fragmented Landscapes for the Conservation of Birds: A General Framework and Specific Recommendations for Urbanizing Landscapes.- Steps Involved in Designing Conservation Subdivisions: A Straightforward Approach.- Beyond Greenbelts and Zoning: A New Planning Concept for the Environment of Asian Mega-Cities.
332 citations
TL;DR: In this article, the authors consider the needed adaptation and mitigation agenda for cities in India - where the urban population is likely to grow by around 500 million over the next 50 years.
Abstract: This paper considers the needed adaptation and mitigation agenda for cities in India - where the urban population is likely to grow by around 500 million over the next 50 years. It considers the likely changes that climate change will bring in temperature, precipitation and extreme rainfall, drought, river and inland fl ooding, storms/storm surges/coastal fl ooding, sea-level rise and environmental health risks, and who within urban populations are most at risk. It notes the importance for urban areas of an effective rural adaptation agenda - especially in maintaining the productivity and functioning of rural systems. It highlights the importance of today's infrastructure investments, taking into account climate changes, given the long lifespan of most infrastructure, and the importance of urban management engaging with changing risk profi les. One important part of this is the need to connect offi cial adaptation initiatives to the much-improved natural hazard risk assessment, management and mitigation capacity that responded to major disasters. The paper ends by describing a possible urban climate change adaptation framework, including changes needed at the national, state, city and neighbourhood levels, and linkages to mitigation.
317 citations
TL;DR: In this article, the authors examined how proximity to urban agglomeration affects contemporary population growth in hinterland U.S. counties and found strong negative growth effects of distances to higher-tier urban areas, with significant, but lesser, effects of distance to market potential, consistent with various recent theories stressing the importance of how new technology affects the spatial distribution of activity in a mature urban system.
Abstract: The sources of urban agglomeration and the urban hierarchy have been extensively studied. Despite the pivotal role of the hinterlands in theories of the development of the urban hierarchy, little attention has been paid to the effect of urban agglomeration on growth in the hinterlands, particularly in a developed, mature economy. Therefore, this study examines how proximity to urban agglomeration affects contemporary population growth in hinterland U.S. counties. Proximity to urban agglomeration is measured in terms of both distances to higher-tiered areas in the urban hierarchy and proximity to market potential. Particular attention is paid to whether periodic changes and trends in underlying conditions (e.g., technology or transport costs) have altered population dynamics in the hinterlands and small urban centers. Over the period 1950-2000, we find strong negative growth effects of distances to higher-tiered urban areas, with significant, but lesser, effects of distance to market potential. Further, the costs of distance, if anything, appear to be increasing over time, consistent with various recent theories stressing the importance of how new technology affects the spatial distribution of activity in a mature urban system, while factors associated with the New Economic Geography are of lesser importance. (This abstract was borrowed from another version of this item.)
224 citations
TL;DR: Surface water qualities in urban and suburban areas were improved by strengthening the environmental policies and management, but were worsening in rural areas, suggesting that decision makers and city officials should be more aware of the recent pollution increases in Shanghai.
211 citations
TL;DR: In this paper, the authors developed a system dynamics simulation model of the drivers and environmental impacts of urban growth, using Shenzhen, South China, as a case study, and developed scenarios to evaluate the impact of urban development on several environmental indicators: land use, air quality, and demand for water and energy.
Abstract: China is home to one-fifth of the world's population and that population is increasingly urban. The landscape is also urbanizing. Although there are studies that focus on specific elements of urban growth, there is very little empirical work that incorporates feedbacks and linkages to assess the interactions between the dynamics of urban growth and their environmental impacts. In this study, we develop a system dynamics simulation model of the drivers and environmental impacts of urban growth, using Shenzhen, South China, as a case study. We identify three phases of urban growth and develop scenarios to evaluate the impact of urban growth on several environmental indicators: land use, air quality, and demand for water and energy. The results show that all developable land will be urban by 2020 and the increase in the number of vehicles will be a major source of air pollution. Demand for water and electricity will rise, and the city will become increasingly vulnerable to shortages of either. The scenarios also show that there will be improvements in local environmental quality as a result of increasing affluence and economic growth. However, the environmental impacts outside of Shenzhen may increase as demands for natural resources increase and Shenzhen pushes its manufacturing industries out of the municipality. The findings may also portend to changes other cities in China and elsewhere in the developing world may experience as they continue to industrialize.
210 citations
TL;DR: In this paper, the authors present a characterisation for Greater Manchester which uses urban morphology type mapping and surface cover analysis, which is potentially useful for strategic urban planning in relation to climate change adaptation and for green infrastructure planning in particular.
TL;DR: This paper found that rural-urban migration in the Amazon Basin is an extended and complex process and that Amazonian migrants remain members of multi-sited households and continue to participate in rural networks and in rural land-use decisions.
Abstract: In much of the Amazon Basin, approximately 70% of the population lives in urban areas and urbanward migration continues. Based on data collected over more than a decade in two long-settled regions of Amazonia, we find that rural–urban migration in the region is an extended and complex process. Like recent rural–urban migrants worldwide, Amazonian migrants, although they may be counted as urban residents, are often not absent from rural areas but remain members of multi-sited households and continue to participate in rural–urban networks and in rural land-use decisions. Our research indicates that, despite their general poverty, these migrants have affected urban markets for both food and construction materials. We present two cases: that of acai palm fruit in the estuary of the Amazon and of cheap construction timbers in the Peruvian Amazon. We find that many new Amazonian rural–urban migrants have maintained some important rural patterns of both consumption and knowledge. Through their consumer behavior, they are affecting the areal extent of forests; in the two floodplain regions discussed, tree cover is increasing. We also find changes in forest composition, reflecting the persistence of rural consumption patterns in cities resulting in increased demand for and production of acai and cheap timber species.
TL;DR: The implications of an increasingly urban world population on local, regional, and global nitrogen cycles are focused on and a variety of approaches for minimizing and mitigating the impacts of urban N concentration are proposed.
Abstract: The concentration of materials and energy within cities is an inevitable consequence of dense populations and their per capita requirements for food, fiber, and fuel. As the world population becomes increasingly urban over the coming decades, urban areas will dramatically affect the distribution of nutrients across the face of the planet. In many cities, technological developments and urban planning have been effective at reducing the amount of waste nitrogen that is ultimately exported to downstream surface waters, largely through investments in sanitary sewer infrastructure and wastewater treatment. There are, however, still large cities throughout the developed world that have failed to take advantage of these obvious innovations to reduce their impact on downstream ecosystems. In addition, very few cities have adequately addressed the problems of diffuse nitrogen pollution, instead city infrastructure is often designed to route this N directly into downstream ecosystems. In the developing world, many of these problems are more acute, as rapidly growing urban populations exceed the capacity of limited municipal infrastructure. Reducing urban N pollution of groundwaters and surface waters both locally and globally can only be achieved through cultural and political adaptation in addition to technological innovations. In this review, we will focus on the implications of an increasingly urban world population on local, regional, and global nitrogen cycles and propose a variety of approaches for minimizing and mitigating the impacts of urban N concentration.
TL;DR: In this paper, an analysis of the interdependencies of the impacts of climate change and adaptation strategies upon infrastructure systems in the Metro Boston urban area in the northeastern USA found that taking anticipatory actions well before 2050 results in less total adaptation and impact costs to the region than taking no actions.
Abstract: An analysis of the interdependencies of the impacts of climate change and adaptation strategies upon infrastructure systems in the Metro Boston urban area in the northeastern USA found that taking anticipatory actions well before 2050 results in less total adaptation and impact costs to the region than taking no actions. Because of the interrelations among infrastructure systems, it is critical to take account of the impacts that adaptation actions have on each other and other systems. For the most part these cross-system effects are complementary in nature. But there are important exceptions, so an integrated approach to adaptation policy formulation is needed. Furthermore, adaptation efforts must be designed so as not to confound mitigation efforts.
TL;DR: The majority of heat-related fatalities during the summer of 2003 were in urban areas as mentioned in this paper, and the urban heat island effect is responsible for temperature differences of up to 71C between cities and the country in the UK.
TL;DR: In this article, the authors highlight the varied impacts of cities on soils and their implications for restoration planning and expectations of restoration success, including the creation of novel soil types, conditions that promote invasion by non-natives, and the presence of strong interactions and alternative stable states set up unique difficulties for the restoration of urban soils.
Abstract: Current and predicted trends indicate that an increasing proportion of the world’s population is living in urban and suburban places. The nature of the urban environment becomes an important factor if we are concerned with the restoration and preservation of biodiversity and ecosystems in and around cities. This article highlights the varied impacts of cities on soils and their implications for restoration planning and expectations of restoration “success.” Urban soils exist in different historical and formational trajectories than their local nonurbanized counterparts due to direct anthropogenic disturbance and indirect environmental impacts from urbanization. Therefore, urban soils often exhibit altered physical, chemical, and biological characteristics in comparison to local nonurbanized soils. Several unique features of urban soils and urban ecosystems pose particular issues for ecological restoration or the improvement of degraded soil conditions in cities. The creation of novel soil types, conditions that promote invasion by non-natives, the strong influence of past land use on soil properties, and the presence of strong interactions and alternative stable states set up unique difficulties for the restoration of urban soils. Soils in urban restorations are a medium that can be deliberately manipulated to improve site conditions or in the monitoring of soil conditions as indices of ecosystem status. Including an explicit role for strong manipulations of soils in urban ecosystems changes how we approach baselines, management, and reference conditions in urban ecological restoration. With an understanding of urban soil ecological knowledge, we can guide aspects of urban ecological restoration toward successful outcomes.
TL;DR: In this paper, the authors summarize how irrigation and water application technologies; landscape design and management strategies; the relationship among people, plants, and the urban landscape; the reuse of water resources; economic and noneconomic incentives; and policy and ordinances impact the efficient use of water in the urban landscapes.
Abstract: In the United States, urban population growth, improved living standards, limited development of new water supplies, and dwindling current water supplies are causing the demand for treated municipal water to exceed the supply. Although water used to irrigate the residential urban landscape will vary according to factors such as landscape type, management practices, and region, landscape irrigation can vary from 40% to 70% of household use of water. So, the efficient use of irrigation water in urban landscapes must be the primary focus of water conservation. In addition, plants in a typical residential landscape often are given more water than is required to maintain ecosystem services such as carbon regulation, climate control, and preservation of aesthetic appearance. This implies that improvements in the efficiency of landscape irrigation will yield significant watersavings.UrbanareasacrosstheUnitedStatesfacedifferentwatersupplyanddemand issues and a range of factors will affect how water is used in the urban landscape. The purpose of this review is to summarize how irrigation and water application technologies; landscape design and management strategies; the relationship among people, plants, and the urban landscape; the reuse of water resources; economic and noneconomic incentives; and policy and ordinances impact the efficient use of water in the urban landscape.
01 Jan 2008
TL;DR: The authors found that affluent whites were more likely to live in vegetated and less climatically stressed neighborhoods than low-income Latinos in Phoenix, Arizona, and that these neighborhoods had cooler summer temperatures that reduced exposure to outdoor heat-related health risks, especially during a heat wave period.
Abstract: The urban heat island is an unintended consequence of humans building upon rural and native landscapes. We hypothesized that variations in vegetation and land use patterns across an urbanizing regional landscape would produce a temperature distribution that was spatially heterogeneous and correlated with the social characteristics of urban neighborhoods. Using biophysical and social data scaled to conform to US census geography, we found that affluent whites were more likely to live in vegetated and less climatically stressed neighborhoods than low-income Latinos in Phoenix, Arizona. Affluent neighborhoods had cooler summer temperatures that reduced exposure to outdoor heat-related health risks, especially during a heat wave period. In addition to being warmer, poorer neighborhoods lacked critical resources in their physical and social environments to help them cope with extreme heat. Increased average temperatures due to climate change are expected to exacerbate the impacts of urban heat islands.
TL;DR: In this paper, a thorough literature study of more than 200 publications, a number of interesting conclusions about this important environmental and socio-economical phenomenon can be made, including the following: low density, apparently random, scattered or fragmented and leap frogging forms of urban land use, not classified as core urban fabric (Town, city,... ) nor classified as real ‘countryside’ are studied.
Abstract: Urbanization is a well-known topic in sustainable development debates as it is known to have great impacts on landscape and environment. Low density, apparently random, scattered or fragmented and leap frogging forms of urban land use, not classified as core urban fabric (town, city, . . . ) nor classified as real ‘countryside’ are studied in this paper. With a thorough literature study of more than 200 publications, a number of interesting conclusions about this important environmental and socio-economical phenomenon can be made. At first, it is generally described as either a type of land use or land use dynamic functioning as ‘divide’ between city and countryside (the urban fringe theory), or it is very often described as the dynamic and fast transformation of rural land into urban land (the sprawl approach). In some cases it forms its own ‘landscape’ and it is called the peri-urban or more correctly semi-urban area. Generally, there seems to be a lack of good definitions and frameworks, although it is studied often and in various scientific disciplines. Prominently, there is an always present dichotomy between rural and urban in all concepts, theories and definitions proposed.
TL;DR: In 2006, California's Global Warming Solutions Act of 2006 set ambitious goals for reductions in CO2 emissions, which the state must now figure out how to achieve as discussed by the authors, one of the most controversial issues in the world.
Abstract: California's Global Warming Solutions Act of 2006 set ambitious goals for reductions in CO2 emissions, which the state must now figure out how to achieve. One of the most controversial issues relat...
TL;DR: In this article, a multi-criteria assessment scheme (MCA) was developed and applied to assess the socio-environmental impact of shrinkage in urban areas, in order to identify infrastructure and land use changes related to vacancy and demolition.
TL;DR: The CAPITOUL experiment as discussed by the authors is a joint experimental effort in urban climate, including the energetic exchanges between the surface and the atmosphere, the dynamics of the boundary layer over the city and its interactions with aerosol chemistry.
Abstract: The CAPITOUL experiment is a joint experimental effort in urban climate, including the energetic exchanges between the surface and the atmosphere, the dynamics of the boundary layer over the city and its interactions with aerosol chemistry. The campaign took place in the city of Toulouse in southwest France, for one year, from February 2004 to February 2005. This allowed the study of both the day-to-day and seasonal variability of urban climate processes. The observational network included surface stations (meteorology, energy balance, chemistry), profilers and, during intensive observing periods, aircraft and balloons.
TL;DR: In this article, the authors used the technique of statistical downscaling through exemplar studies of London's future urban heat island and peak ozone concen- trations, derived from atmospheric variables supplied by four general circulation models driven by a medium-high (A2) emissions scenario for the 2050s.
Abstract: As the global population becomes increasingly urbanised, so interest has grown in the potential climate change impacts on city infrastructure, services, and environmental quality. However, urban areas are only beginning to be represented explicitly in the land-surface schemes of dynamical climate models through modified energy and moisture budgets. This paper summarises recent evi- dence of urban impacts on climate and vice versa. The technique of statistical downscaling is then introduced through exemplar studies of London's future urban heat island and peak ozone concen- trations. Projections of both indices are derived from atmospheric variables supplied by four general circulation models, driven by a medium-high (A2) emissions scenario for the 2050s. The results show further intensification of the nocturnal heat island and higher ozone concentrations that are most pronounced in summer. These changes reflect sensitivity to variations in regional climate alone, so omit other factors such as changes in land use, emissions, climate feedbacks, or synergies between air quality and heat islands. Nonetheless, the downscaled scenarios are consistent with an emerging picture of increasing risks to human health in urban areas unless appropriate adaptation measures are taken.
TL;DR: An analysis of 6 years of heat-related dispatches through the Phoenix Fire Department regional dispatch center to examine temporal, climatic and other non-spatial influences contributing to high-heat-related medical dispatch events identified that there were no significant variations in day-of-week dispatch events.
Abstract: Heat waves kill more people in the United States than hurricanes, tornadoes, earthquakes, and floods combined. Recently, international attention focused on the linkages and impacts of human health vulnerability to urban climate when Western Europe experienced over 30,000 excess deaths during the heat waves of the summer of 2003-surpassing the 1995 heat wave in Chicago, Illinois, that killed 739. While Europe dealt with heat waves, in the United States, Phoenix, Arizona, established a new all-time high minimum temperature for the region on July 15, 2003. The low temperature of 35.5 degrees C (96 degrees F) was recorded, breaking the previous all-time high minimum temperature record of 33.8 degrees C (93 degrees F). While an extensive literature on heat-related mortality exists, greater understanding of influences of heat-related morbidity is required due to climate change and rapid urbanization influences. We undertook an analysis of 6 years (2001-2006) of heat-related dispatches through the Phoenix Fire Department regional dispatch center to examine temporal, climatic and other non-spatial influences contributing to high-heat-related medical dispatch events. The findings identified that there were no significant variations in day-of-week dispatch events. The greatest incidence of heat-related medical dispatches occurred between the times of peak solar irradiance and maximum diurnal temperature, and during times of elevated human comfort indices (combined temperature and relative humidity).
TL;DR: In this article, the effects of urban design on the water balance, with a focus on evapotranspiration and storm water, were analyzed using a water balance modelling framework.
Abstract: Using a water balance modelling framework, this paper analyses the effects of urban design on the water balance, with a focus on evapotranspiration and storm water. First, two quite different urban water balance models are compared: Aquacycle which has been calibrated for a suburban catchment in Canberra, Australia, and the single-source urban evapotranspiration-interception scheme (SUES), an energy-based approach with a biophysically advanced representation of interception and evapotranspiration. A fair agreement between the two modelled estimates of evapotranspiration was significantly improved by allowing the vegetation cover (leaf area index, LAI) to vary seasonally, demonstrating the potential of SUES to quantify the links between water sensitive urban design and microclimates and the advantage of comparing the two modelling approaches. The comparison also revealed where improvements to SUES are needed, chiefly through improved estimates of vegetation cover dynamics as input to SUES, and more rigorous parameterization of the surface resistance equations using local-scale suburban flux measurements. Second, Aquacycle is used to identify the impact of an array of water sensitive urban design features on the water balance terms. This analysis confirms the potential to passively control urban microclimate by suburban design features that maximize evapotranspiration, such as vegetated roofs. The subsequent effects on daily maximum air temperatures are estimated using an atmospheric boundary layer budget. Potential energy savings of about 2% in summer cooling are estimated from this analysis. This is a clear ‘return on investment’ of using water to maintain urban greenspace, whether as parks distributed throughout an urban area or individual gardens or vegetated roofs. Copyright © 2007 John Wiley & Sons, Ltd.
TL;DR: In this paper, the authors presented a formulation and evaluation of an urban parameterization designed to represent the urban energy balance in the Community Land Model, and tested the robustness of the model through sensitivity studies and the model's ability to simulate urban heat islands in different environments.
Abstract: In a companion paper, the authors presented a formulation and evaluation of an urban parameterization designed to represent the urban energy balance in the Community Land Model. Here the robustness of the model is tested through sensitivity studies and the model’s ability to simulate urban heat islands in different environments is evaluated. Findings show that heat storage and sensible heat flux are most sensitive to uncertainties in the input parameters within the atmospheric and surface conditions considered here. The sensitivity studies suggest that attention should be paid not only to characterizing accurately the structure of the urban area (e.g., height-to-width ratio) but also to ensuring that the input data reflect the thermal admittance properties of each of the city surfaces. Simulations of the urban heat island show that the urban model is able to capture typical observed characteristics of urban climates qualitatively. In particular, the model produces a significant heat island that increases with height-to-width ratio. In urban areas, daily minimum temperatures increase more than daily maximum temperatures, resulting in a reduced diurnal temperature range relative to equivalent rural environments. The magnitude and timing of the heat island vary tremendously depending on the prevailing meteorological conditions and the characteristics of surrounding rural environments. The model also correctly increases the Bowen ratio and canopy air temperatures of urban systems as impervious fraction increases. In general, these findings are in agreement with those observed for real urban ecosystems. Thus, the model appears to be a useful tool for examining the nature of the urban climate within the framework of global climate models.
Book•
01 Jan 2008
TL;DR: In this paper, the authors present a landscape ecology of cities and urban forest management in China with an emphasis on Shanghai, focusing on the effects of land use on forest Remnants.
Abstract: Preface.- Part One: Perspectives and Approaches in Urban Forestry: Introduction: The Growth of Cities and Urban Forestry.- Towards a Landscape Ecology of Cities: Beyond Buildings, Trees, and Urban Forests.- Principles for Guiding Eco-City Development.- A Multiple-Indicators Approach for Monitoring Urban Sustainable Development.- Assessment and Valuation of the Ecosystem Services Provided by Urban Forests.- Benefits of Urban Green Space for Improving Urban Climate.- Applying Ecosystem Management to Urban Forestry.- Approaches to Urban Forestry in the United Kingdom.- Opportunities and Alternatives for Enhancing Urban Forests in Compact Cities in Developing Countries.- Urban Ecology Studies in China with an Emphasis on Shanghai.- Using the Urban-Rural Gradient Approach to Determine the Effects of Land Use on Forest Remnants.- A Philosophical Basis for Restoring Ecologically Functioning Urban Forests: Current Methods and Results.- Part Two: Planning, Managing and Restoring Urban Forests: Strategic Planning for Urban Woodlands in North West England.- Landscape Corridors in Shanghai and their Importance in Urban Forest Planning.- Management of Urban Forests in the U.S.A.- The Urban Forest of Nanjing City: Key Characteristics and Management Assessment.- Urban Forest Structure in Hefei, China.- Forests and Forestry in Hesse (Federal Republic of Germany): Meeting the Challenge of Multipurpose Forestry.- Experiences in the Management of Urban Recreational Forests in Germany.- Modeling the Social Benefits of Urban Parks for Users.- Potential Leaf Area Index Analyses for the Urban Forest in Toronto, Canada.- Spatial and Temporal Change in the Distribution of Urban Vegetation in Beijing.- Long-Term Observations of Secondary Forests Growing on Hard Coal Mining Spoils in the Industrial Ruhr Region of Germany.- Selection of Pollution Tolerant Trees for Restoration of Degraded Forests and Evaluation of the Experimental Restoration Practices at the Ulsan Industrial Complex, Korea.- Restoration Planning in the Seoul Metropolitan Area, Korea.- the Construction of Near-Natural Forests in the Urban Areas of Shanghai.- Part Three: Synthesis and Directions for Future Research, Planning, and Implementation: The Future of Urban Forestry: Comparing National and International Needs and Perspectives.- Appendix: Recommendations for Urban Forestry and Planning in Shanghai.- Index.
01 Jan 2008
TL;DR: In this article, the authors argue that to provide sufficient quality of life in high density cities, it is important to maintain and restore an urban green space system; moreover, urban green spaces and a comfortable urban climate also produce social and economic benefits.
Abstract: Urban settlements transform the natural environment so greatly that people tend to see the city only as an employment site, and economic and cultural center. Thus a growing number of people prefer to reside in greener suburbs or rural areas. This results in increased automobile commuter traffic, accompanied by traffic jams, accidents, stress, and ever more damage to the environment. Concepts of sustainable development or the ecological city represent strategies for changing these negative trends. The purpose for doing so is principally the well-being of a city’s residents. Often this entails bringing more of the natural environment back into the city, because urban green space fulfills several critical functions in an urban context that benefit people’s quality of life. There is a broad consensus about the importance, and therefore the value, of urban green space in cities as currently constructed, in addition to its value in planning ecological cities. Steadily growing traffic and urban heat not only damage the environment, but also incur social and economic costs. As we explain further, we can save costs even by making small changes to existing situations. Furthermore, we maintain and show that an integrated approach is needed for designing and maintaining urban green space. The main thesis of this chapter, therefore, is as follows: To provide sufficient quality of life in high-density cities, it is important to maintain and restore an urban green space system; moreover, urban green space and a comfortable urban climate also produce social and economic benefits.
TL;DR: This article analyzed the evolution of built landscapes in six U.S. metropolitan regions using historic maps, aerial photographs, and GIS software, identifying seven main historic patterns of urban form and nine types created in the 1980-2005 period.
Abstract: This article analyzes the evolution of built landscapes in six U.S. metropolitan regions using historic maps, aerial photographs, and GIS software. The analysis identifies seven main historic patterns of urban form and nine types created in the 1980-2005 period. This recent period was characterized by a proliferation and fragmentation of built landscape types, rapid spatial expansion, and falling densities. These trends raise the question of whether the public sector should more proactively shape urban form. Rural sprawl accounts for much of the land now being urbanized, representing a new planning challenge. The Portland Urban Growth Boundary is found to be effective at limiting this type of development. The New Urbanist neighborhood form is still extremely rare.
TL;DR: In this paper, the authors review common population and community-level responses of wildlife to urbanization, and discuss how: (1) the amount and configuration of land cover and land use, and (2) the alteration of resources (e.g., natural disturbance regimes, species interactions, intensity of human recreation) within built environments influence animals, with special emphasis on birds.
Abstract: We review common population and community-level responses of wildlife to urbanization, and discuss how: (1) the amount and configuration of land cover and land use, and (2) the alteration of resources (e.g., type of vegetation, presence of food and water) and processes (e.g., natural disturbance regimes, species interactions, intensity of human recreation) within built environments influence animals, with special emphasis on birds. Although each landscape presents unique opportunities and constraints, we suggest that all urban areas have the potential to contribute to the conservation of biodiversity. The ecological value of urban areas may be promoted if planners, managers, and homeowners consider ways to (1) encourage retention and protection of natural habitats within urbanizing landscapes, (2) plan explicitly for open spaces and natural habitats within new subdivisions, (3) use a variety of arrangements of built and open space within developments, (4) enhance and restore habitat within open spaces, (5) improve quality of developed lands (i.e., the urban matrix) rather than directing management efforts only towards parks, reserves, and open areas, and (6) celebrate urban biological diversity to foster connections between people and their natural heritage.