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1.
The biotopes of ecological importance in urban environments worldwide are under the pressure of many negative factors such as urbanization, air pollution, human disturbance, etc. Biotope mapping is an important tool for urban planning and management and of importance for the protection of biotopes for future generations. The biotopes in Antalya city of Turkey, which has faced to a great population pressure due to tourism developments and immigration in the last two decades, were investigated in this study. The selective biotope mapping method was used and major biotope sites were determined by the interpretation of panchromatic aerial photographs, assisted with field verifications. A sensitivity assessment based on two parameters, the rarity and the re-establishment ability of biotopes, was made as it was considered important information for urban planning and management. According to the results of the assessment, the majority of biotopes in Antalya city were found to be very sensitive or sensitive. It was concluded that insufficient legislation, the lack of an ecological urban planning approach and poor urban management are the most important reasons for today's pressures on urban biotopes in Turkey.  相似文献   

2.
Parks, waterways, and vegetation enhance the well-being of urbanites and thus warrant consideration in planning and policy-making. It is, however, difficult to assess how land-use change may impact these features and how this in turn may impact well-being. I use a case-study approach to present a framework that combines geospatial and economic valuation techniques to generate indicators of the effects of land-use policies that alter these amenities on community well-being. This framework quantifies the impacts of land-use change on urban environmental amenities in a way that could help communities plan land use so as to maintain well-being as they urbanise.  相似文献   

3.
ABSTRACT

A growing number of cities are incorporating resilience into their plans and policies to respond to shocks, stresses, and uncertainties. While some scholars advocate for the potential of resilience research and practice, others argue that it promotes an inherently conservative and neoliberal agenda, prevents systemic transformations, and pays insufficient attention to power, politics, and justice. Notably, critics of the urban resilience agenda argue that policies fail to adequately address social equity issues. This study seeks to inform these debates by providing a cross-sectional analysis of how issues of equity are incorporated into urban resilience planning. We develop a tripartite framework of equity that includes distributional, recognitional, and procedural dimensions and use it to analyse the goals, priorities, and strategies of formal resilience plans created by member cities of the Rockefeller Foundation’s 100 Resilient Cities programme. Our analysis reveals considerable variation in the extent to which cities focus on equity, implying that resilience may be more nuanced than some critics suggest. There are, however, clear areas for improvement. Dominant conceptions of equity are generally tied to a distributional orientation, with less focus on the recognitional and procedural dimensions. We hope our conceptual framework and lessons learned from this study can inform more just resilience planning and provide a foundation for future research on the equity implications of resilience.  相似文献   

4.
This study examined the relationship between urban experience, indexed by residential proximity to and lifetime frequency of contact with an urban center, and the ability to identify five different levels of information pertinent to navigation. Lower levels included traditional spatial components of place, path and node. Higher levels included functional urban goals (destinations) and their strategic ordering (itineraries). Identifications of each component were made from photographs of its parts. Identifications of destinations and itineraries correlated highly with nodes. Indices of experience correlated more highly with functional than spatial identifications. More experienced subjects generally identified more components at all levels, and higher-level identifications were generally more difficult, but closer residents were less likely to find functional identifications more difficult than spatial. Results are discussed in terms of skill acquisition and variations in urban transactions.  相似文献   

5.
Denitrification potential in urban riparian zones   总被引:3,自引:0,他引:3  
Denitrification, the anaerobic microbial conversion of nitrate (NO3-) to nitrogen (N) gases, is an important process contributing to the ability of riparian zones to function as "sinks" for NO3- in watersheds. There has been little analysis of riparian zones in urban watersheds despite concerns about high NO3- concentrations in many urban streams. Vegetation and soils in urban ecosystems are often highly disturbed, and few studies have examined microbial processes like denitrification in these ecosystems. In this study, we measured denitrification potential and a suite of related microbial parameters (microbial biomass carbon [C] and N content, potential net N mineralization and nitrification, soil inorganic N pools) in four rural and four urban riparian zones in the Baltimore, MD metropolitan area. Two of the riparian zones were forested and two had herbaceous vegetation in each land use context. There were few differences between urban and rural and herbaceous and forest riparian zones, but variability was much higher in urban than rural sites. There were strong positive relationships between soil moisture and organic matter content and denitrification potential. Given the importance of surface runoff in urban watersheds, the high denitrification potential of the surface soils that we observed suggests that if surface runoff can be channeled through areas with high denitrification potential (e.g., stormwater detention basins with wetland vegetation), these areas could function as important NO3- sinks in urban watersheds.  相似文献   

6.
The twentieth century saw a dramatic increase in the production of urban solid waste, reflecting unprecedented global levels of economic activity. Despite some efforts to reduce and recover the waste, disposal in landfills is still the most usual destination. However, landfill has become more difficult to implement because of its increasing cost, community opposition to landfill siting, and more restrictive environmental regulations regarding the siting and operation of landfills. Moreover, disposal in landfill is the waste destination method with the largest demand for land, while land is a resource whose availability has been decreasing in urban systems. Shortage of land for landfills is a problem frequently cited in the literature as a physical constraint. Nonetheless, the shortage of land for waste disposal has not been fully studied and, in particular, quantified. This paper presents a method to quantify the relationship between the demand and supply of suitable land for waste disposal over time using a geographic information system and modelling techniques. Based on projections of population growth, urban sprawl and waste generation the method can allow policy and decision-makers to measure the dimension of the problem of shortage of land into the future. The procedure can provide information to guide the design and schedule of programs to reduce and recover waste, and can potentially lead to a better use of the land resource. Porto Alegre City, Brazil was used as the case study to illustrate and analyse the approach. By testing different waste management scenarios, the results indicated that the demand for land for waste disposal overcomes the supply of suitable land for this use in the study area before the year 2050.  相似文献   

7.
Denitrification in alluvial wetlands in an urban landscape   总被引:1,自引:0,他引:1  
Riparian wetlands have been shown to be effective "sinks" for nitrate N (NO3-), minimizing the downstream export of N to streams and coastal water bodies. However, the vast majority of riparian denitrification research has been in agricultural and forested watersheds, with relatively little work on riparian wetland function in urban watersheds. We investigated the variation and magnitude of denitrification in three constructed and two relict oxbow urban wetlands, and in two forested reference wetlands in the Baltimore metropolitan area. Denitrification rates in wetland sediments were measured with a 15N-enriched NO3- "push-pull" groundwater tracer method during the summer and winter of 2008. Mean denitrification rates did not differ among the wetland types and ranged from 147 +/- 29 microg N kg soil(-1) d(-1) in constructed stormwater wetlands to 100 +/- 11 microg N kg soil(-1) d(-1) in relict oxbows to 106 +/- 32 microg N kg soil(-1) d(-1) in forested reference wetlands. High denitrification rates were observed in both summer and winter, suggesting that these wetlands are sinks for NO3- year round. Comparison of denitrification rates with NO3- standing stocks in the wetland water column and stream NO3- loads indicated that mass removal of NO3- in urban wetland sediments by denitrification could be substantial. Our results suggest that urban wetlands have the potential to reduce NO3- in urban landscapes and should be considered as a means to manage N in urban watersheds.  相似文献   

8.
Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.  相似文献   

9.
Feasibility versus sustainability in urban water management   总被引:1,自引:0,他引:1  
Decision making in urban water management is exemplified by the case of Austria: Although researchers define a comprehensible concept of sustainability, practitioners emphasize feasibility and accept limitations in sustainability. Could the specification of particular methods, chosen from some decision support methodology, remedy this situation? While an integrative assessment of sustainability should not be based on prescribed or standardized criteria, or even a certain assessment method, it should force the decision makers to make their chosen premise more visible. To this end a change of the decision making process is proposed, which will allow the decision makers to adapt the decision making process to the circumstances of a specific project in a way that is accepted by the stakeholders.  相似文献   

10.
11.
Environmental management involves controlling various forms of pollution to levels that do not pose a threat to the health of the people and the environment in general. This paper presents a framework to analyze sources of local air pollution in cities. Using an OLS model, an investigation is performed of the relationship among the concentrations of air pollutants [more precisely, concentrations of sulfur dioxide (SO2), dust, nitric oxide (NO), nitrogen dioxide (NO2), carbon oxide (CO) and ozone (O3)], economic activities, and meteorology. Time series analysis leads to a model, that explains a high degree of the variance in the air pollution data. The model is applied to daily time series from three measurement stations in innsbruck, Austria. Estimation results of the model generally fit with the expected relations. Space heating influences SO2, dust, and NO, while NO2 levels are primarily affected by traffic. These results also indicate interdependent relations among the pollutants NO, NO2, O3, and CO; O3 levels depend on temperature and sunshine.  相似文献   

12.
13.
In Canada, increasing costs of maintenance, a shifting perception of what makes a city beautiful, a recognition of the needs and the importance of urban wildlife, and changing recreational demands are all contributing to a pressure for change in current practice. This study examines the extent to which the ecological approach has influenced the design and management of urban green space in Canada, focusing on the city of Toronto and its surrounding region as an example.  相似文献   

14.
The concept of sustainable development has become very much in vogue in the past decade. We have also observed a shift in the interpretation of this concept from a global perspective to a meso perspective—that is, at a local, regional or sectoral level. This paper aims at highlighting the urban dimension of environmental issues. After a sketch of urban pollution problems and of tools for economic analysis, the notion of urban sustainability will be advocated as a meaningful analytical and policy concept. Next, the main focus of this paper will be on a typological approach to urban sustainability issues on the basis of three characteristic angles, viz. strong and weak sustainability, absolute and relative decoupling and the spatial ecological footprint. Various methodological issues will also be discussed, while the paper will conclude with some perspectives on policy issues. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

15.
Urban regeneration policy and projects could facilitate the implementation of spatial policy responses to mitigate climate change and adapt to its consequences in cities. However, the potential role of urban regeneration in creating climate-friendly urban environments is not sufficiently evaluated and understood. Considering this gap, the paper aims to explore the potential linkage between urban regeneration and climate change. The case study analysis focuses on two urban regeneration projects, representing two major approaches of regeneration practices in Japanese cities, namely “project-based” and “plan-based” approaches. Research findings demonstrate that urban regeneration could help in reorganising existing urban areas in a climate-friendly manner. As a cross-cutting field of urban policy, urban regeneration could also help in creating synergies between mitigation and adaptation goals. Yet, achievement of such outcomes via regeneration projects necessitates the existence of an overriding urban development vision, political commitment, and willingness to implement binding and structural measures.  相似文献   

16.
The occurrence of heavy metals in the soil was measured over a period of several years to determine background concentrations in a heavily urbanized watershed in southeastern Michigan. A spatially dispersed sample was collected to capture the inherent variability of the soils and historic land use. The analysis focused on 14 metals (antimony, arsenic, barium, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc) that are part of the USEPA's list of the 129 most common pollutants. Metal concentrations were measured at three depths: near-surface (<0.5 m), shallow subsurface (0.5-10 m), and depths greater than 10 m across six soil units in glacial terrain. Additional analyses assessed the metal concentrations in each depth profile across three general land use categories: residential, commercial, and industrial. Metal concentrations were the highest in the near-surface with Pb present at concentrations averaging 15.5 times that of background in industrial areas and approximately 16 times background in residential areas. Cadmium, Hg, and Zn were also present in surface soils at levels of several times that of background. The highest concentrations of each of these metals were present in the clay-rich soils located in the eastern, more urbanized and industrialized part of the watershed. Metals detected at elevated concentrations decreased in concentration with increasing depth and distance from the urbanized and industrialized center of the watershed. Statistically significant differences in the concentrations of heavy metals were also noted between the land use categories, with Cd, Cr, Cu, Pb, Ni, and Zn observed within industrial areas at mean concentrations several times greater than background levels.  相似文献   

17.
Economic valuation of urban forest benefits in Finland   总被引:13,自引:0,他引:13  
Urban development projects may cause loss of amenity values of green areas, which should be taken into consideration in planning. Therefore, quantitative information on residents' valuation concerning urban forests is needed for assessing urban land use. The purpose of this investigation was to study the valuation of urban forests in two different urban environments Joensuu and Salo, Finland. The aims were to study the attitudes towards and benefits related to the use of urban forests and, in particular, to measure the valuations in monetary terms using contingent valuation, i.e. measure the residents' willingness-to-pay for larger wooded recreation areas and for small forested parks. Urban forests were seen in both towns as clearly producing positive benefits rather than causing negative effects. The negative features of forests were related to the management of the areas rather than their existence. The main values were related to nature and social functions of forests. In contrast, timber production achieved a distinctively low priority in both study towns. The results stress the importance of defining urban forest policies for municipalities in Finland. More than two-thirds of the respondents were willing to pay for the use of recreation areas. Good location and active management raised the average WTP. Moreover, approximately half of the respondents were willing to pay for preventing construction in urban forests. The results also show that the monetary value of amenity benefits in recreation areas is much higher than the present maintenance costs. The examples concerning the advantageousness of construction on green areas suggest that a limit could be found where the infill of housing areas is not worthwhile from the point of view of society, if the losses of green space benefits are taken into account.  相似文献   

18.
Nutrient contribution of leaf litter in urban stormwater   总被引:1,自引:0,他引:1  
This paper investigates the nutrient contribution from leaf litter in urban waterways, using data from a gross pollutant monitoring programme in a 50 ha catchment in an inner-city suburb of Melbourne, Australia. The data indicate that the potential nutrient contribution of stormwater leaf litter (greater than 5 mm) is about two orders of magnitude smaller than the typical nutrient loads in urban stormwater. The results suggest that removing leaf litter from urban waterways will do little to reduce the total stormwater nutrient load.1998 Academic Press  相似文献   

19.
Saudi Arabia has undergone revolutionary change to its economy since 1973, followed more recently by serious economic problems. The largely peripheral effects of urban planning upon the transformation of Jeddah from medieval town to international city are considered. The main urban problems and opportunities facing the city are identified, and the paper concludes with a question against the relevance of ‘Western’ notions of planning to another culture undergoing dynamic urban change.  相似文献   

20.
Perceived safety from crime in the urban environment   总被引:1,自引:0,他引:1  
Two studies were conducted to test various aspects of Appleton's Prospect-Refuge Theory. Hypotheses derived from the theory predicted that observers would rate how safe from crime they would feel in specific urban environments on the basis of whether the environments offered visibility (light), prospect (open spaces) and unambiguous refuge (a place where a criminal would not see the intended victim, or where other, non-threatening people were likely to to be present). It was further hypothesized that women in general would feel less safe from crime than men. In Study 1, University students generated lists of environmental features relevant to safety. Light was the most frequently mentioned factor, followed by open space and unambiguous refuge. In Study 2, slides were presented in which these three characteristics were independently varied. The results supported all of the hypotheses.  相似文献   

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