- 1 Mẹo về Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? Mới Nhất
- 2 Handbook of Regional and Urban Economics
- 3 Urban Geography
- 4 Discrete Urban Economic Theory
- 5 Cities and Geography
- 6 Spatially Explicit Analysis in Environmental Studies
- 7 Cities: Internal Structure
- 8 Ecological Footprint, Concept of
- 9 Land-Use Issues
- 10 Neighborhood: General
- 11 Implications of Urbanization for Conservation and Biodiversity Protection
- 11.1 Ecosystem Service Provision
- 11.2 Which of the following best describes the connection between range and threshold?
- 11.3 Which of the following statements best explains urban growth in the period from 2000 to 2010?
- 11.4 Which of the following best explains a geographic characteristic shared by megacities in the global periphery?
- 11.5 What is a common impact of urbanization regardless of a country’s level of economic development?
- 11.6 Review Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? ?
- 11.7 Share Link Cập nhật Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? miễn phí
Mẹo về Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? Mới Nhất
You đang tìm kiếm từ khóa Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? được Update vào lúc : 2022-08-24 06:20:20 . Với phương châm chia sẻ Thủ Thuật Hướng dẫn trong nội dung bài viết một cách Chi Tiết 2022. Nếu sau khi Read nội dung bài viết vẫn ko hiểu thì hoàn toàn có thể lại Comments ở cuối bài để Tác giả lý giải và hướng dẫn lại nha.
Handbook of Regional and Urban Economics
Nội dung chính
- Handbook of Regional and Urban Economics8.1 IntroductionUrban Geography1.2.2 Urban function and urban social structureDiscrete Urban
Economic TheoryCharacteristics of the MarketCities and Geography3.4.2 Urban densitiesSpatially Explicit Analysis in Environmental Studies2.3 Urban Land UseCities: Internal Structure1.2.2 Land values gradientEcological Footprint, Concept ofThe Functional Footprints of CitiesLand-Use IssuesUrbanization in Western Washington StateNeighborhood:
Generation: The Era of the BulldozerImplications of Urbanization for Conservation and Biodiversity ProtectionEcosystem Service ProvisionWhich of the following best describes the connection between range and threshold?Which of the following statements best explains urban growth in the period from 2000 to 2010?Which of the following best explains a geographic characteristic shared by megacities in the global periphery?What is a common impact of urbanization regardless of a country’s level of economic development?
Gilles Duranton, Diego Puga, in
Handbook of Regional and Urban Economics, 2015
In this chapter, we provide an integrated treatment of the theoretical literature on urban land use
inspired by the monocentric model, including extensions that giảm giá with multiple endogenous business centers, various dimensions of heterogeneity, and durable housing. After presenting the theory and distilling its key empirical implications, we critically review the empirical literature on differences in prices and development across urban locations, patterns of location choices of heterogeneous households in cities, sprawl and residential decentralization, and employment decentralization.
Urban land use is of fundamental importance. Most obviously, it is the heart of extremely large allocation decisions made by firms and households. On the residential side, American households devote about a quarter of their consumption expenditure to housing, and the value of the residential housing stock may represent up to 2 years of gross national product. Where development occurs and what intensity is arguably a first-order determinant of the efficiency
of these large allocations. Households also engage in a variety of activities that take place in different locations: they work, they sleep, they play, they go to school, they shop, they visit friends, they go to the dentist, etc.1 To conduct these activities in different locations, people must travel between them. As a result, land use and transport are intimately connected. American households spend between 5% and 10% of their time awake traveling, and the median
household devotes 18% of its budget to transport, most of which goes to road transport.2
Beyond this, urban land use is a fundamental determinant of the physical world that surrounds urban dwellers, the majority of the world population. Urban land use determines how the various locations urban dwellers go to or would like to go to are organized and connected with each other. Hence, not only does land use affect the immense resources
devoted to housing, commercial property, open space, and transport, it also potentially affects the labor market and the markets for the products we purchase. Land use also arguably affects the ability of firms to produce. In turn, these broader effects of land use may have serious implications for prosperity and equity.
Figure 8.1 depicts the distribution of land across various uses in Paris. The map the top of the figure classifies
land across five uses on a disk with radius 30 km centered on Notre Dame, the conventional center of Paris. We can immediately see that the patterns of land use are quite complex. The next two plots summarize the information by classifying land use by distance from Notre Dame, with the northern half of the map plotted on the positive side of the horizontal axis and the southern half plotted on the negative side.3 The first of these two plots splits all land between
open space, land used for transport infrastructure, and built-up land. The last plot further divides the built-up land category between multifamily residential, single-family residential, and commercial uses. Both plots show some very clear gradients. In particular, as we look further away from the center (Notre Dame), the percentage of land that is built up falls, with more land being open space instead. The intensity of residential development also falls very clearly with distance to the
center, with multifamily buildings giving way very quickly to single-family homes. The distribution of built-up land between residential and commercial uses does not show much variation by comparison, but we do see two peaks of commercial land (pointing downward, since commercial is plotted the top) the sides of a central area with more mixed use. It is also worth noting how much space is taken up by transport infrastructure, particularly close to the center, a very graphic illustration of
how closely tied transport is to land use issues in cities. The rest of the chapter will help the reader to understand both the complexity and the order that appear in Figure 8.1.
Figure 8.1. Distribution of land across uses in Paris.
Before proceeding any further, we will draw some intellectual boundaries for this chapter and justify its organization further. Since everything is located somewhere, land use potentially touches on a large number of topics. At minimum, it could certainly overlap greatly with all the other chapters in this volume. To retain a
finite agenda, we think of urban land use as covering mainly the following issues: (a) the differences in land and property prices across locations, (b) the patterns of location choices by types and subgroups of users, (c) the patterns of land conversion across uses, and (d) the patterns of residential and business location changes within cities.
To explore these four sets of issues, we first present an integrated summary of theoretical developments on urban
land use before turning to the empirical work on the aforementioned issues. A first reason for using this structure instead of providing a different model for each empirical question is that the theory that underlies the issues listed above is unified. There is no point repeating it several times. Furthermore, the economic analysis of land use first saw some important theoretical developments with empirical work lagging behind or developing independently.4 We endeavor to
reconnect empirical work more strongly with theory both by making sure that we highlight the empirical content of the models as we describe them and by trying to tie empirical work to land use models as strongly as possible (or by highlighting the weakness of those links in some cases). Another reason for presenting the theory in a self-contained manner is that it is relevant not only to the issues explored here, but also to many issues explored in other chapters in this volume such as
regulation, neighborhood dynamics, and transport, to list just a few.
Following a long and well-established economic literature, our starting point is that accessibility determines land and housing prices different locations. However, the patterns of accessibility are also affected by the location choices of firms and workers, which are determined by prices. Hence, the land use problem is in essence a hard equilibrium problem with many feedbacks. The
literature first solved it by restricting accessibility to be solely about access to jobs and by treating the location of these jobs as exogenous within a simple geography and with frictionless markets. This is the monocentric model that we explore in Section 8.2.
While the simplest version of the monocentric model may be viewed as a reasonable first-order description of many cities and delivers a number of plausible predictions, it remains
extremely crude. Even if we are willing to restrict production in cities to take place in a centralized area, the model does not include a number of fundamental urban features. In particular, city dwellers are highly heterogeneous in their incomes, demographics, and preferences. The study of the heterogeneity of urban residents is interesting in itself since, beyond making predictions about prices and the intensity of development, we also expect good models of land use to offer insights into who
lives where. The heterogeneity of residents, coupled with that of the housing stock, also implies that land and property markets may not be as frictionless as assumed in the simplest land use models. In addition, the basic model is static in nature, but properties are long-lived and we cannot expect land use in cities to adjust immediately to any shock. This creates further frictions. We explore all these issues in Section 8.3.
But perhaps the
most obvious criticism of the monocentric model is that cities have become less and less monocentric. The main problem with the standard approach is not that it cannot accommodate more realistic employment distributions. It can. What the standard approach cannot do easily is allow the distribution of jobs to be endogenous, interacting with the distribution of residents. Much modeling effort has been devoted to this problem since the late 1970s. Residents face a trade-off between accessibility
and land and property prices. Businesses benefit from proximity to other businesses because of agglomeration economies but, if they cluster, they must pay higher land prices and also compensate their workers for longer commutes with higher wages. Section 8.4 provides a tractable model of land use in cities under endogenous business location dealing with these complex issues and summarizes other efforts modeling secondary centers and job decentralization.
No work on urban land use would be complete without a discussion of government intervention. Land and the properties erected on it are usually highly regulated. We explore and discuss the possible reasons for these regulations and their possible effects in Section 8.5.
Our treatment of the theoretical literature gives a dominant role to the accessibility of jobs. While clearly important, job accessibility is not
the sole determinant of how land is used and how properties are valued. First, commuting is only one aspect of urban travel. Thus, accessibility should be broadly understood to include proximity to shops, school, amenities, etc. Second, other aspects of location, such as heterogeneity and neighborhood interactions, matter greatly. This said, we believe focusing on accessibility is warranted because it seems uniquely important in shaping cities a broader scale.
To be useful and become more than a speculation, a conceptualization must confront the empirical reality. This is what the last four sections of our chapter aim to do. Section 8.6 examines the empirical literature that assesses the gradient predictions of the simplest models of urban land use. Section 8.7 then turns to the empirical location patterns of heterogeneous city residents. Section 8.8 looks recent patterns of
residential land development. Finally, Section 8.9 examines changes in business location within cities.
Read full chapter
R. Schneider-Sliwa, in International Encyclopedia of the Social & Behavioral Sciences, 2001
Analysis of urban land use development, urban functions, and specializations: specialized economic activities seek locations with the greatest competitive advantage. This approach helps to
understand urban land use development and to determine those land use patterns that most competitively provide basic tư vấn for the city. The internal structures of specialized urban functions (wholesale, retail, service activity, etc.) within the city and their market orientation, i.e., urban locations that are best suited to meet the city’s needs, are points of focus. On the micro scale of the city, the analysis of central business districts and neighborhood business/convenience centers have
received priority. On the meso and macro scales of urban systems analysis, the degree of specialization in and between cities is considered the base for identifying a city’s market potentials, strengths, and niches within a regional or national hierarchy of cities.
Empirical examination of factors organizing space and megalopolitan structure đơn hàng with the metropolis as a changing configuration and the processes by which metropolitan areas grow and expand
beyond their rigid corporate limits. Studies of metropolitan patterning examine the functional differentiation of suburbs, the interrelation of the city and its surrounding area through economic linkages and commuting, and the way metropolitan communities reorganize themselves into supra-metropolitan areas. The development of megalopoles, the increasing functional specialization of metropolitan centers and communities, and their growing interdependency are key research issues.
Urban social geography and the factorial ecology of cities, social status differentiation, and segregation: urban areas are highly differentiated complex systems (see also Cities, Internal Organization of in this volume). These approaches giảm giá with urban sub-areas, urban subpopulations, social and economic characteristics of urban neighborhoods, the social patterning of local residents by race, ethnicity, and class, and the behavior of
subpopulations as a function of their social group, race, and class, or as mediated by the characteristics of the neighborhood, urban sub-area, and the urban system.
Urban sub-area characteristics and urban social and spatial differentiation are commonly analyzed using factorial ecology. This term refers to various statistical approaches using factor analytic methods. Small area analyses with a limited set of variables grounded in social theory are common.
Factor analysis, on the other hand, depends on a large number of variables that are then reduced in an exploratory way to essential properties of a particular phenomenon of urban sub-areas or urban space. It determines urban sub-areas according to common social characteristics or in terms of households or individuals with common characteristics.
The urban ecologist or social geographer does not focus on spatial differentiation per se. Rather, social
and spatial patterns are regarded as the manifestation of a social process. Indeed, the urban social geographer or urban ecologist studies such patterns with a view to uncovering the social, political, economic, or cultural processes that may be responsible for these patterns. Residential segregation of different social status groups, for example, occurs in many different cultural settings and reveals the most residentially segregated social groups, for example, as those the top and the
bottom of the social status hierarchy. In increasingly multicultural societies, patterns of differentiation among social groups and neighborhoods and their particular spatial geometry are becoming a growing problem. Factorial ecological investigations that use a variety of computational techniques help identify the differences between social, demographic, and economic characteristics in urban space. They help to monitor processes of social distance as reflected in the degree of physical distance
and residential separation.
Perception of the urban environment: this approach sees age and social status-related perceptions of the urban environment, personal activity radius, and spatial behavior as related variables. Individual perceptions of reality affect spatial behavior, be it shopping trips or intra-urban migration. For example, characteristics of the automobile society, such as the monotonous urban landscape, can negatively affect an individual’s
identification with the physical urban environment and may induce him/her to move, thus contributing to the erosion of a city’s tax base and concomitant inner city decline.
Differing social and age groups, for example, the elderly, the youth, the poor, have distinct ranges of activities and different patterns of spatial behavior in urban space. Market research utilizes the results of studies on the perception of the urban environment and spatial behavior. At
the micro scale of individual urban geography, studies concentrate on activities that a person does regularly and urban places that are visited regularly, i.e., daily or weekly, as they form the basis of the personal contact field and average information field. These may be analyzed using the methods of time geography and indicate an individual’s capabilities to overcome distance by means of mobility and communication. At the macro scale, the collective spatial behavior of social groups and the
spatial geometries of social group behavior are focused upon. Decisions regarding distances between shopping centers and other central urban functions, for example, make use of empirical findings of collective spatial behaviors (see Behavioral Geography; Urban Activity Patterns).
Personal mental/cognitive pictures of space are also referred to as images. The analysis of these images focuses on the subjective
evaluation of urban space by residents, visitors, business people, and potential investors. Perceptual geographic urban analysis upholds the theory that spatial behavior, like intra-urban migration or shopping and recreational activity, is often limited to a closed field of perception and reference, and it is affected by personal spatial evaluation. The overall image of a city from the point of view of a commercial interest is affected by the ‘soft’ locational factors (e.g., amenities,
attractiveness of the urban environment, social and demographic processes in the city, or business climate). Image analysis can contribute significantly towards finding reasons for the exodus of population, companies, and enterprises, or disinvestment. Moreover, measures for the improvement of a negative city image or for instigating desired development can be recommended (see Spatial Cognition).
Read full chapter
Francisco Javier Martínez Concha, in Microeconomic Modeling in Urban Science, 2022
Characteristics of the Market
analysis of urban land and real estate markets requires that we consider specific characteristics of this market: spatial context, real estate heterogeneity, consumer interactions, and inelastic demand; when combined, these characteristics yield a theory of the urban LU market.
The spatial context of this market, which was introduced in the previous chapter in the discussion of concepts associated with accessibility, is the first and most evident
characteristic. Contrary to the classical notion of the market as the place where consumers and suppliers meet and trade, in this case, the spatial distribution of the land makes each location different or differentiable from all the others, i.e., each alternative location is different. Unlike products, the LU market has no factory that can produce as many equal copies as demanded a price. This distinction was observed by classical economists, who interpreted the specific commodity of land to
be a monopolistic market in which the owner holds the monopoly of the access, a transportation cost, to the central business district (CBD). Alonso’s seminal work (1964) proposed the bid-auction theory, interpreting this market as an auction of differentiated goods. From that point, the urban economic theory developed as a continuous space model.
The discrete modeling described in this book provides a more realistic approach by assuming a
heterogeneous space, where buildings are developed from land previously used and partitioned into land lots in a continuous development process. Additionally, consumers are seen as heterogeneous and as valuing a variety of attributes of alternative locations. This setting provides the flexibility that explains why this approach is used in applied models of cities to analyze how the city is predicted to evolve from the current situation.
Recognizing that land is already divided into land lots and built on, this approach provides the modeler with a highly diverse representation of real estate alternatives described by a large set of different attributes, including building characteristics, land size, neighborhood, and accessibility or transportation costs.
LU consumers are household and firm residents who value each location for the interactions that each one can perform with the
rest. We discussed this concept in Chapter 2, observing the value that consumers assign to different locations according to their accessibility and location externalities. From the modeler’s point of view, this calls for a theory of the impact of these interactions in the market that produces evident structures on a macroscale in the city, as for example, the social exclusion phenomena on household residents or the agglomeration of industries and commercial activities.
LU demand is highly inelastic because a population of consumers needs to be located somewhere in the city. More specifically, the total demand for real estate units is inelastic any time, whereas building densities make demand for a specific land lot and floor space more elastic because the same number of agents may be accommodated with different floor space to land ratios.
In the first part of this chapter, we
present a discrete theory of how consumers behave in this market. We then discuss how suppliers develop land into real estate options and how buildings are redeveloped. Finally, we propose a model of the market performance to show how prices are formed and how the auction process matches consumer and supplier behavior. In this chapter, the theory is presented for an ideal static equilibrium, which assumes that information is perfect for all agents and that all real estate units available in the
market are sold simultaneously. This ideal scenario enables us to understand the fundamental forces and characteristics of this market. In the following chapters, we relax the perfect information assumption to develop more applicable models that remain consistent with the theory presented here.
Read full chapter
Cities and Geography
Sukkoo Kim, Robert A. Margo, in
Handbook of Regional and Urban Economics, 2004
3.4.2 Urban densities
While the density gradient and other measures of decentralization are informative, we believe that a study
of simple average density of cities provides a fuller picture of urban spatial structures. Shammas (2000) finds that colonial cities were compact and dense. In 1800, data on sample of four cities (Philadelphia, Tp New York, Baltimore and Boston) indicate that each city consisted of less than 2 square miles of area. Population densities of these cities ranged from Boston’s 20,781 to Philadelphia’s 45,800 persons per square mile. The differences in population densities in these cities
reflected their differences in housing lot sizes. It appears that Philadelphia’s high density relative to other cities was due to its relatively small house lot sizes. While Philadelphians averaged 7.1 compared to Boston’s 8.7 persons per dwelling, Philadelphia’s house lot sizes only averaged 1392 square feet as compared to Boston’s 3441.
Unfortunately, systematic information on urban land areas is available only
from 1890 onwards with the publication of the Social Statistics of Cities. Kim (2002) finds that urban densities rose and fell between the late nineteenth and the twentieth centuries. Between 1890 and 1950, average population density rose from 7230 to 8876 persons per square mile for a consistent sample of cities whose population was greater than 25,000 (see Table 4 and Figure 6).24
During this period, the cities also annexed considerable amounts of land. In 1890, the cities averaged approximately 19 square miles of land; by 1950, they averaged 40 square miles. Yet, despite the significant increases in the boundaries of cities, population density rose as urban population growth outpaced annexation. However, in the second half of the twentieth century, the average population density of cities declined substantially. By 1990, average population density fell to 5647 persons
per square mile. In this period, cities continued to annex nearby areas, but urban population growth did not keep pace with annexation. For metropolitan areas, Kim (2002) finds that average density rose between 1940 and 1960 but then fell sharply between 1960 and 1990.
Table 4. Population and employment densities of cities, 1890–1990
Number of citiesAverage population (sq. miles)Average areaAverage population density1890
Note. The data, except for years 1910–1930, are for cities with population over 25,000. In 1890, two cities were omitted due to lack of data on land area. Cities in Alaska and Hawaii are excluded.
*Data for 1910–1930 are for cities with population over 30,000.
Sources. Social Statistics of Cities, 1890; Census of Population, 1900;
Financial Statistics of Cities, 1910, 1920, 1930; County and City Data Book, 1949, 1952, 1962, 1972, 1982, 1988, 1994.
Copyright © 1930
6. Population density of cities, 1890–1990 (persons per square mile). For a colour reproduction of this figure see the colour figures section, page 3073.
Sources: see Kim (2002).Copyright © 2002
The combined information from urban densities and density gradients presents a more coherent picture of the changes in urban spatial structures between the late nineteenth
and the twentieth centuries. The average densities of urban areas rose and fell over time; however, density gradients of urban areas declined monotonically over time. These two trends can be reconciled accordingly. Between 1890 and 1950, the density gradient curve shifted upward but its slope fell, causing urban density to rise even as the density gradient declined. However, between 1950 and 1990, the density gradient curve shifted downward as its slope continued to fall, causing urban density
to decline sharply.
By concentrating most of their empirical analysis on the density gradient, largely motivated by the monocentric city model, Kim (2002) argues that urban economists have under-emphasized the location decisions of firms and its impact on urban spatial structures. Although falling transportation costs and rising incomes tended to disperse households outwards, Kim suggests that firm agglomeration economies in manufacturing and
business services may have contributed to the rise in urban density during the first half of the twentieth century. Moreover, advances in skyscraper technologies lowered the costs of dense employment, especially for sectors that used office space. However, in the second half of the twentieth century, the decline in the importance of agglomeration economies in employment, re-enforced by household’s preference for living in larger housing away from the city center, is likely to have contributed to
the decline in average urban density as well as the continuing decline in the density gradient.25
Read full chapter
Spatially Explicit Analysis in Environmental Studies
J. Geoghegan, in
International Encyclopedia of the Social & Behavioral Sciences, 2001
2.3 Urban Land Use
The location, distribution and pattern of urban land uses and urban fringe development have major effects on the environment. It is the pattern of development that determines the amount and type of nonpoint source pollution into water bodies; loss of farmland and other open-space amenities; the amount of commuting with associated air pollution and congestion; as well as ecological effects, including hydrological disturbances and habitat fragmentation.
There is a rich social science literature of spatial models of urban land use. The classic monocentric city model is an equilibrium model of urban spatial structure, where the distribution of land uses on a featureless plain around a central business is a result of an equilibrium between the declining land price gradient and increasing transportation costs. In its simplest form, concentric rings of residential development around the urban center describe the resulting equilibrium pattern of land
use and decreasing residential density as distance from the urban center increases. More sophisticated versions of the model have been developed, but nonetheless, the model’s ability to explain observed land use patterns is weak. In comparing the model’s predictions with actual land-use patterns, the model fails to explain the complexity of the spatial and temporal patterns of urban growth. This limitation is partly due to the treatment of space, which is assumed to be a ‘featureless plain’ and
is reduced to a simple measure of distance from the urban center.
Some research has tried to overcome the ‘featureless plain’ assumption by including some of the heterogeneous landscape features that exist, for example, by focusing on how individuals value different landscape arrangements. In a study of individual preferences concerning agricultural land abandonment and subsequent spontaneous reforestation, Hunziker and Kienast (1999) use
photographs of different stages of reforestation to elicit respondents’ most preferred pattern of land uses and find that there are particular arrangements of the landscape that are preferred by individuals. In order to test the hypothesis that individuals value the pattern of land uses surrounding their homes, Geoghegan and colleagues (1997), have created spatial indices of land use fragmentation and diversity measured different scales, and include these variables in a spatially
explicit model of residential land values. Results demonstrate that individuals prefer to have a homogenous distribution of land use in the immediate area surrounding their homes, but a more heterogonous distribution of land uses on a larger scale.
The spatial interdependencies among land use, zoning regulations and on ecosystems are modeled in Bockstael and Bell (1997). A spatially explicit modeling approach is necessary in order to understand how
these regulations affect development decisions across the landscape and in turn how the location of nutrients from point sources, such as sewer treatment plants, and nonpoint sources, for example, septic fields affect water quality. They find that differential zoning across regions deflects development from one region to another and that the amount of increased nitrogen loadings from a constant amount of new development varies from 4–12 percent, depending on the degree of difference across
In the urban land-use models introduced above, the theoretical structure assumes a very simple concept of spatial human behavior—that individuals only respond to exogenously determined locations of landscape features. Other models allow for the potential spatial interactions among individuals. An approach that can be used to model this interaction explicitly is a cellular automata model, where behavior of a system is generated by a set of
deterministic or probabilistic rules that determine the discrete state of a cell based on the states of neighboring cells. Despite the simplicity of the transition rules, these models, when simulated over many time periods, often yield complex and highly structured patterns. Researchers have used cellular automata models to analyze the process of urban growth (e.g. Clarke et al. 1997, White et al. 1997). In contrast to the standard urban economic models of urban
structure introduced above, in which complex patterns are generated by imposing external conditions, these models demonstrate how complex structure arises internally from the interaction among individual cells. While these models fit the spatial process and the spatial evolution of urban land uses when compared with urban forms in the USA, because these models impose the land-use transition rules there is very little policy-relevant context to these models.
limitation is overcome in a cellular automata approach used by Irwin and Bockstael (1999) to predict patterns of land use change in an urbanizing area, in which the transition probabilities are estimated as functions of a variety of exogenous variables and an interaction term that captures the effect of neighboring land use conversions. They then use a cellular automata model, with estimated parameters of land conversion, to demonstrate that a model in which there are spatial
interactions between the land use decisions of individuals result in the evolution of a fragmented land-use pattern that is qualitatively much more similar to the observed pattern of development than the pattern that is predicted by models that ignore these spatial interactions. Models that include improved understanding of the spatial evolution of urban land use, when linked with a spatial ecosystem model, will be able to make much better predictions of the effects of government policies
concerning land use on ecosystems.
Read full chapter
Cities: Internal Structure
E. Lichtenberger, in International Encyclopedia of the Social & Behavioral Sciences, 2001
1.2.2 Land values gradient
According to the theory of urban land markets (Alonso 1964), urban land use mirrors transport cost as well as the rent of land. Regularly, in socio-economically intact city centers, there is a center-periphery gradient with several consecutive zones of use outward from the central business district
(CBD). Replacement of historical city-models by the new model of suburbia together with the reduction in accessibility have made for an abandonment of central areas, resulting in ‘craters’ of land prices and visible decay of inner cities in the USA and parts of Western Europe. In the centers, the gradient now falls in the opposite direction. The Alonso model excludes restrictions on planning land use and vertical development. With zoning laws, building categories, and other legal regulations,
the gradient of real estate prices is altered. Each category or zone is divided in two, with the inner zone obviously better suited for business purposes and office space than the outer zone that is used for dwelling as it is more profitable (see Fig. 3).
Figure 3. Land values gradient and zoning
Read full chapter
Ecological Footprint, Concept of
William E. Rees, in
Encyclopedia of Biodiversity (Second Edition), 2013
The Functional Footprints of Cities
These findings should alter our perceptions about many things. To begin,
they should change how we think about cities and urban land. Over 40 years ago, American ecologist Eugene Odum wrote, “Great cities are planned and grow without any regard for the fact that they are parasites on the countryside which must somehow supply food, water, air, and degrade huge quantities of waste” (Odum, 1971). Ecofootprinting enables us to quantify the extent of this urban parasitism. For example, in 2006, Canada’s largest city, Toronto, had a population of approximately
2,503,281 living in an area of 630 km2. Assuming they are typical Canadians, Toronto’s citizens had an average EF of about 7.4 gha (18 acres). Thus, the EF of Toronto was 185,243 km2 or about 294 times the size of its political area. Clearly, most of the city’s supportive ecosystems are located a great distance from the people they sustain; indeed, they are scattered all over the planet.
This situation is
characteristic of high-income cities. In a particularly comprehensive analysis, Folke et al. (1997) estimated that the 29 largest cities of Baltic Europe appropriate for their resource consumption and waste assimilation an area of forest, agricultural, marine, and wetland ecosystems 565–1130 times larger than the areas of the cities themselves. A study for the International Institute for Economy and Development in London shows that the ecological demands of that city alone
appropriate an area scattered around the world equivalent to the entire biocapacity of the UK.
Such findings have important implications for both urban development and rural sustainability in the twenty-first century. Some analysts interpret the global migration of people from rural areas to the city as implying that modern humans are abandoning the countryside and becoming less dependent on the land. This is an illusion. The reality is that productive
croplands, pasture lands, and forests everywhere are being used more intensely than ever to sustain the world’s burgeoning urban populations. The human occupants of cities may think of the latter as their principal habitat, but cities per se represent only a tiny fraction of the total increasingly urban-centered human ecosystem.
There is, of course, a certain mutualism between the city and the countryside. Cities need the resources of rural areas and rural
areas benefit from urban markets and technology transfers from cities. However, while rural areas could survive without cities, the dependence of cities on rural environments is absolute. In short, there can be no urban sustainability without rural sustainability. In this light, we might even want to reconsider what we think of as urban land – in a whole-systems ecological sense, the great plains of North America, one of the world’s major breadbaskets, are an essential component of the
increasingly urban global human ecosystem.
According to United Nations’ projections, there will be 27 cities with populations exceeding 10 million by 2015 (up from only 1 in 1950). Forty-four more cities will have populations of 5–10 million by the same year. This should trigger least a cautionary alarm. The world’s megacities – all cities for that matter – are dependent on a vastly larger area of productive lands outside their boundaries and political
control. But just how secure can any urban population be if the lands represented by its ecofootprint are under threat from climate change or the population’s access to essential biocapacity is denied by resource scarcity (think peak oil) or geopolitical turmoil?
Read full chapter
Kees Klein Goldewijk, in
Encyclopedia of Biodiversity (Second Edition), 2013
Urbanization in Western Washington State
An expanding population and the world’s appetite for resources have
transformed much of North America from extensive forest and grassland to agricultural and urban land (compare Figures 2 and 3). The general story is similar to the case in Southeast Asia. However, in the Pacific Northwest a more dramatic and permanent conversion of land is occurring a rapid rate. Logging during the last 50 years has converted more than two-thirds of the primary forest in Washington to secondary forest. Rather than continuing to manage these forests
for timber production, much of the land is now being converted to human settlements. In western Washington, for example, human populations have doubled in the last 50 years and are expected to double again in the next 50 years. From 1998 to 2000, Washington is expecting a net gain of one person every 5 min! This places a premium value on land for settlement. The predictable result is a rapid conversion of forest to urban and suburban settlements. Indeed, from 1970 to 1997, Washington lost
2.3 million acres of managed forestland. Urban expansion was responsible for about half of this loss. Rights-of-way and agriculture accounted for the rest.
The increasing urbanization in western Washington threatens to reduce biodiversity. Water flows altered by settlement have reduced the spawning and rearing habitat for the region’s spectacular salmon diversity. As a result, several salmon runs have been extinguished and many are now listed as endangered.
Loss of forests and intensification of resource extraction and recreation on remaining forests have contributed to the endangerment of several birds (e.g., Spotted Owls, Strix occidentalis, and Marbled Murrelets, Brachyramphus marmoratus), mammals (e.g., Grizzly Bear, Ursus arctos, and Gray Wolf, Canis lupus), and amphibians (Larch Mountain Salamander, Plethodon larselli). Drainage of wetlands and settlement of native woodlands and grasslands have
endangered amphibians (Oregon Spotted Frog, Rana luteiventris), insects (Oregon Silverspot butterfly, Speyeria zerene), mammals (Western Gray Squirrel, Sciurus griseus), and reptiles (Western Pond Turtle, Clemmys marmorata).
Some species benefit whenever land cover changes. A good example of such a species is the American Crow (Corvus brachyrhynchos) in western Washington. Crows are found only in close association
with human settlement. As a result, their numbers have increased 10-fold from 1960 to 1995. Increases in human commensals like crows may have a ripple effect through the native biota. Crows prey on the eggs and young of other birds, which may limit their reproduction and reduce overall biodiversity close to human settlements even in remaining forest reserves.
Read full chapter
N. Carmon, in International Encyclopedia of the Social & Behavioral Sciences, 2001
Generation: The Era of the Bulldozer
This phase was characterized by physical determinism and emphasis on the built environment.
Intolerable housing conditions in old and very old neighborhoods in the growing cities, coupled with the wish to make ‘better use’ of central urban land and drive the poor out of sight, gave birth to the idea of slum clearance. Large-scale clearance programs were implemented in the UK
(1930–39) (1954–1970s), the USA (1937–64), Canada (1948–68), France (1958–75), and many other countries. In the European states, the public authorities managed both the clearance and the provision of housing to the relocatees. The result was that most of the displaced households were rehoused. In the USA, by contrast, concentration and clearance of land sites was generally done by public agencies, while the new construction was in the hands of private entrepreneurs. As a consequence, the number
of apartments demolished under the aegis of the urban renewal programs in the USA was much greater than the number of units built. The slum areas were frequently replaced by shopping centers, office buildings, and cultural and entertainment centers, all of which were in high demand in the boom years that followed World War II. The few housing developments built were generally designated for people with higher socioeconomic status than those who were
relocated. Gans (1965) found that between 1949 and 1964 only one half of one percent of all expenditures by the American federal government for urban renewal was spent on relocation of the families and individuals removed from their homes.
Despite the significant differences in the nature of activity between countries, the criticism voiced against most of the clearance and redevelopment projects was similar (Wilmott and Young 1957).
The executors were criticized for ignoring the heavy psychological cost of forced relocation, the social cost of the destruction of healthy neighborhoods and communities, and the cultural cost of erasing old urban fabrics. In many cases where new residential neighborhoods were built, the planners and designers were blamed for building inhuman blocks which were unfit for family life, and certainly not suitable for poor families. The bulldozer approach as a leading regeneration strategy was
condemned and disqualified wherever it was applied.
Read full chapter
Implications of Urbanization for Conservation and Biodiversity Protection
Robert Ian McDonald, in
Encyclopedia of Biodiversity (Second Edition), 2013
Ecosystem Service Provision
Just as cities impact biodiversity, they also impact a myriad of ecosystem processes
in sometimes complex ways (McDonald et al., 2009). For example, fire ignitions tend to increase near urban land uses, increasing the risk of wildfires starting (Matos et al., 2002). However, widespread suppression of fires soon after they start, designed to minimize the risk of damage to property, often decreases the magnitude of fires that do occur. The exact effect on the natural ecosystem varies, but in almost every case
proximity to urban areas alters the fire regime. Occasionally, anthropogenic alteration of the fire regime may have unintended consequences, as when fire suppression leads to fuel buildup, increasing the risk of catastrophic fire.
Altered ecosystem processes of course lead to altered ecosystem service provision as well (McDonald and Marcotullio, 2011). An example might be the capacity of the atmosphere and biosphere to absorb atmospheric
pollutants or mitigate their effect. Removal of forest cover as cities grow reduces standing carbon stock and decreases carbon sequestration. Without natural land cover, the natural ability of vegetation to moderate temperature swings is lost and the urban heat island effect (the tendency of cities to be warmer than their surroundings) is magnified (cf. Kalnay and Cai, 2003). In some cases, the loss vegetation also decreases the environment’s ability to absorb or filter low-level
air pollutants (Escobedo and Nowak, 2009). However, for other low-level air pollutants like VOC, natural vegetation can actually enhance formation of the pollutant, with negative effects to human health (Leung et al.).
Another example of an ecosystem service affected by urbanization would be the water quality (Carpenter et al., 1998). Once urbanization passes a certain threshold in a watershed, water
quality is significantly degraded. Urbanization, and particularly new construction activities that disturb the soil, increases sedimentation into streams. Excess nutrients, often from sewage or lawn fertilizer, end up running into streams as well. Finally, in hot climates water running into streams after flowing across hot pavement may thermally shock freshwater ecosystems. All of these factors negatively impact freshwater provision for people downstream (McDonald, 2009).
Read full chapter
Which of the following best describes the connection between range and threshold?
Which of the following BEST describes the connection between range and threshold of any particular business? Range đơn hàng with the maximum distance that people are willing to travel for a good or service whereas threshold is the minimum number of people needed for that business to survive.
Which of the following statements best explains urban growth in the period from 2000 to 2010?
Which of the following statements best explains urban growth in the period from 2000 to 2010 ? The greatest percentage growth in population occurred in counties adjacent to the three largest metropolitan areas, indicating continued suburbanization.
Which of the following best explains a geographic characteristic shared by megacities in the global periphery? Megacities demonstrate unplanned growth patterns and often contain squatter settlements.
What is a common impact of urbanization regardless of a country’s level of economic development?
What is a common impact of urbanization regardless of a country’s level of economic development? A. Urbanization means a loss of agricultural production due to the loss of farmland and farmworkers.
Tải thêm tài liệu liên quan đến nội dung bài viết Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range?
Review Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? ?
Bạn vừa tìm hiểu thêm nội dung bài viết Với Một số hướng dẫn một cách rõ ràng hơn về Clip Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? tiên tiến và phát triển nhất
Quý khách đang tìm một số trong những Share Link Down Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? Free.
Thảo Luận vướng mắc về Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range?
Nếu sau khi đọc nội dung bài viết Which of the following best explains the relationship between urban density patterns and the concepts of threshold and range? vẫn chưa hiểu thì hoàn toàn có thể lại Comment ở cuối bài để Tác giả lý giải và hướng dẫn lại nha
#explains #relationship #urban #density #patterns #concepts #threshold #range