Showing papers on "Urban climate published in 2002"

Urbanization, urbanicity, and health

Abstract: A majority of the world's population will live in urban areas by 2007. The most rapidly urbanizing cities are in less-wealthy nations, and the pace of growth varies among regions. There are few data linking features of cities to the health of populations. We suggest a framework to guide inquiry into features of the urban environment that affect health and well-being. We consider two key dimensions: urbanization and urbanicity. Urbanization refers to change in size, density, and heterogeneity of cities. Urbanicity refers to the impact of living in urban areas at a given time. A review of the published literature suggests that most of the important factors that affect health can be considered within three broad themes: the social environment, the physical environment, and access to health and social services. The development of urban health as a discipline will need to draw on the strengths of diverse academic areas of study (e.g., ecology, epidemiology, sociology). Cross-national research may provide insights about the key features of cities and how urbanization influences population health.

Satellite Evidence of Phenological Differences Between Urbanized and Rural Areas of the Eastern United States Deciduous Broadleaf Forest

Abstract: We used a 10-year record (1990–99) of composited and cloud-screened reflectances from the Advanced Very High Resolution Radiometer (AVHRR) to test for phenological differences between urban and rural areas in the eastern United States deciduous broadleaf forest (DBF). We hypothesized that well-documented urban heat island effects would be associated with alterations in temperature-sensitive vegetation phenology. Our objectives were thus (a) to investigate possible differences in the start of the growing season (SOS) and end of the growing season (EOS) between the urban and DBF land covers, (b) to investigate related differences in greenness amplitude and fractional cover, and (c) to develop a generalized additive model (GAM) to predict the spatial variation of observed differences. By analyzing individual 1° latitude by 1° longitude blocks, we found that, on average, urbanization is associated with a growing season expansion of 7.6 days. Most of this effect is caused by an earlier SOS in urban areas. In all cases, urban regions had lower fractional cover and greenness amplitude. The GAM model failed to produce a viable model for differences in EOS, probably because it is dominated by photoperiod controls with only a minor temperature impact. SOS differences were predicted with an accuracy of about 2.4 days, with a GAM consisting of smoothed functions of mean annual average temperature, urban fractional cover, and the urban vs DBF greenness amplitude difference. We speculate that evidence of a phenological response to warming indicates that global warming, without reduction in DBF vegetation cover and greenness amplitude, may increase carbon sequestration in mesic deciduous forests.

Urbanization and warming of Phoenix (Arizona, USA): Impacts, feedbacks and mitigation

Abstract: This paper examines the impacts, feedbacks, and mitigation of the urban heat island in Phoenix, Arizona (USA). At Sky Harbor Airport, urbanization has increased the nighttime minimum temperature by 5°C and the average daily temperatures by 3.1°C. Urban warming has increased the number of “misery hours per day” for humans, which may have important social consequences. Other impacts include (1) increased energy consumption for heating and cooling of buildings, (2) increased heat stress (but decreased cold stress) for plants, (3) reduced quality of cotton fiber and reduced dairy production on the urban fringe, and (4) a broadening of the seasonal thermal window for arthropods. Climate feedback loops associated with evapotranspiration, energy production and consumption associated with increased air conditioning demand, and land conversion are discussed. Urban planning and design policy could be redesigned to mitigate urban warming, and several cities in the region are incorporating concerns regarding urban warming into planning codes and practices. The issue is timely and important, because most of the world's human population growth over the next 30 years will occur in cities in warm climates.

Satellite Monitoring of Urban Spatial Growth in the Atlanta Metropolitan Area

Abstract: Monitoring growth and change along the metropolitan periphery is of critical concern both to those who study metropolitan dynamics and those who must manage resources and provide services in these rapidly changing environments. This research has been directed to assess urban spatial growth and land change along the outskirts of Atlanta, one of the fastest growing metropolitan areas in the United States in the past three decades. A time series of satellite images was used to trace the development of urban land uses for the period of 1973 to the present. An image processing and GIS-based method was developed to achieve the research goal. Results reveal that every week, more than one-hundred acres of forest, green space, and farmland in the Atlanta region were converted into urban uses. Between 1973 and 1999, the urban territorial extent has expanded by 247 percent for 13 metro counties while the population increased by 96 percent. The rate of urban growth was much higher in outer suburban counties. Concomitant with this high rate of urban growth was a farreaching evolution in Atlanta's urban spatial form. The growth of high->ensity urban use (mainly com&ercial, transportation, industrial. and high-rise residential) is found to exwerience a

The Transformation of Cities: Urban Theory and Urban Life

Abstract: Introduction.- Industrial-Modern City.- Demographic Change and the City.- Global Cities.- Everyday Life in the City.- Consumption and Urban Culture.- Urban Social Inequality and Exclusion.- Planning and the Urban Environment.- The Sustainable City.- Reflections.

Effects of Cities on Local Climates

Abstract: For the first time, about half of the world’s population is living in urban areas (Population Reference Bureau, 2001) 95% of the growth over the next three decades will occur in less developed countries, 60% of which will be in Asia (especially China and India) By 2015, 16 of the world’s 24 megacities (cities with more than 10 million people) will be located in Asia The urban transition now underway in Asia involves a volume of population much larger than any other region in the world and is taking place on a scale unprecedented in human history Many of these people will be added to cities whose infrastructure is often already at or beyond its limit which will lead to an inevitable decline in the quality of life and the urban environment Several of these problems are directly or indirectly related to the climate of these cities In mid-latitude cities, heat stress in summer can lead to increased mortality and loss of productivity Increase in pollutant sources both stationary (eg industries) and non-stationary (eg vehicles) result in worsening atmospheric conditions The situation is more dramatic in the less developed world and the tropics Industrial areas are often located with little regard to ventilation and operate with little or no emission control Many cities in the tropics experience weak winds and limited circulation of air which helps the accumulation of pollutants High temperatures increase the production of secondary, photochemical pollutants and the high humidity contributes to a hazy atmosphere In addition cities are a major source of greenhouse gases which are thought to be responsible for the observed global warming trend There are compelling practical issues relating to human health and well-being for which it is important to comprehend the physical basis of urban climates and thence to ensure a pleasant and healthy environment for city dwellers and to reduce the harmful effects of urbanization on large-scale climates Some of the observed urban climate changes, eg temperature increase, have already occurred at a magnitude similar to that projected on a global scale into the future Knowledge of urban weather and climate modification holds lessons for global climate change issues The purpose of this paper is to summarize current knowledge of urban influence on the local climate and discuss practical implications of such understanding Section 2 briefly introduces the background needed to understand why the presence of a city changes the local atmospheric environment Examples of modifications are given in Section 3 The relationship

Time and space scales for measuring urban growth

Abstract: After the last two centuries of intense and unprecedented urbanization, we need a clear understanding of the ongoing trends of urban growth for a better insight of their possible future. Two main processes are analysed: first, the inter-urban concentration of population, with its consequence being a relative decline of the smallest towns; second, urban sprawl, including a shift of population density from the central part of cities towards their peripheries. Using recent data on population and employment in French urban functional areas, we show that the spatial and temporal framework in which urban growth is computed may considerably alter the results and their consecutive interpretation. When the city is defined as a continuously built-up area (the French agglomeration), the measurement of concentration of urban population does not give the same result than when using as a definition the spatial scale of functional urban areas (the French aires urbaines). Similarly, the analysis of the spatial redistribution of population between urban centres, close and outer suburbs are reconsidered under trends of a longer duration and have given very different results, according to the way of defining cities and spaces.

Urbanisation in the Island Pacific: Towards Sustainable Development

Abstract: 1. Introduction: an Urban Pacific Part One: the Context of Urbanization in the Pacific 2. The Colonial Heritage 3. Population Growth and Migration 4. Economic Development: Towards the City? Part Two: Urban Issues 5. Managing Urbanization 6. Land and Urban Life 7. Housing and the Urban Environment Part Three: Sustaining Pacific Urban Society? 8. Living in Town: a Sustainable Future?

Vegetation and population density in urban and suburban areas in the u.s.a

Abstract: Reflectance characteristics of human settlements influence energy fluxes in the physical environment as well as our ability to monitor urban growth with satellite-based sensors. Spectral heterogeneity at the scales of 10 to 30 meters complicate the traditional land cover classifications derived from moderate resolution satellite imagery in urban and suburban areas. In this study we consider population density and vegetation abundance as the principal demographic and physical characteristics in urban and suburban areas of the U.S.A. We investigate their relationship in the cities of Atlanta, Chicago, Los Angeles, New York, Phoenix and Seattle and compare the results with the USGS National Land Cover Dataset’s urban classes. The multimodal population density distribution of the U.S.A. implies that it is possible to characterize suburban areas as those with population densities between 100 and 10,000 people/km, with rural areas at densities below 100 people/km and urban areas at densities above 10,000 people/km. We find that maximum vegetation fraction diminishes with increasing population density over the full range of densities, but the spectral heterogeneity at pixel scales still results in a wide range of vegetation fractions in demographically urban and suburban areas. The resolution difference between census units and the Landsat sensor’s field of view does not allow for a pixel scale spectral characterization of suburban land cover that is consistent with population density. A classification scheme based on spectral heterogeneity at multiple pixel scales, supplemented by auxiliary data sources, may provide a more accurate way to analyze urban growth.

Modelling Spatial and Temporal Road Thermal Climatology in Rural and Urban Areas Using a GIS

Abstract: A 1-D road surface energy balance model was modified to account for the geographical variables of latitude, optical depth, sky-view factor, slope and slope orientation for the West Midlands (UK). The physical variables of albedo, emissivity and surface roughness are also included. Using a satellite land cover classification, aided by a field analysis of urban canyon characteristics, it was pos- sible to estimate the spatial variation of surface variables across the West Midlands. Spatial analysis of the topography was achieved using a Geographical Information System (GIS) database which cal- culated values at 1 km 2 resolution for the geographical variables. This enabled a spatial and tempo- ral analysis of road surface temperatures (retrospectively) across the West Midlands. Sensitivity analysis shows that the geographical variables which have the most significant influence on the model are slope angle and sky-view factor. Validation of the model (West Midlands grid model, WMG) against actual road surface temperature for 15 road weather sensors distributed around the West Midlands, for February 2000, gave R 2 values as high as 0.84; however regression indicated that for 79 nights in the period December 1999 to February 2000 the model overestimated the minimum road surface temperature with a bias of 0.65°C (RMSE 2.07°C), as opposed to the Met Office model (MOM), which underestimated with a bias of -2.03°C (RMSE 3.09°C). Time slices of the model out- put, covering an area of 2400 km 2 , show the development of a surface urban heat island in the West Midlands. The intensity of the modelled heat island is sensitive to the values used for the sky-view factor in the rural areas surrounding the urban conurbation. Winter solstice heat island intensity for calm clear nights in the West Midlands is calculated to be 4.7°C. The structure of the heat island sug- gests that current Open Road weather forecast zones are not applicable in simulated clear calm con- ditions because of the wide range of road surface temperatures caused by the degree of urbanisation.

Urban Sprawl and Rural Landscapes: Perceptions of landscape as amenity in Portland, Oregon

Abstract: In the Portland, Oregon, metropolitan region, an urban growth boundary (UGB) was established in 1979 to protect farm and forest lands from urban encroachment. Most of the literature on the impact of Oregon's land-use legislation has been on the urban side of the issue—primarily the relative success Portland has had in containing urban sprawl. The landscape component of this rural transformation is typically considered only as a passive backdrop to urban expansion. Portland provides an excellent site to examine the relationship city-dwellers have to nearby agricultural areas. Rapid urban growth in the 1990s pushed suburban development to the edge of the UGB creating stark contrasts between urban and rural land uses in parts of the metropolitan area. This study examines the impact of the UGB on rural landscape change in Portland. We combine findings from land-use analysis and surveys of urban and rural residents to suggest ways to merge the amenity values of landscape with planning policy regarding the UGB.

Validation and results of a scale model of dew deposition in urban environments

Abstract: There is growing interest in urban dew and its significance in questions of urban climate and air pollution deposition, but little research has been undertaken to study it. In this study, a generic, urban residential neighbourhood is modelled out-of-doors at a scale of 0.125, using three wooden houses (1.08 m tall), a concrete pavement (1.0 m in width), a grassed park (7.5 m in half-width) and several small trees (up to 1.5 m tall). The thermal inertia of each house is inflated, according to the internal thermal mass (ITM) approach, so that nocturnal surface temperatures are conserved. First-order validation was achieved through comparison with data collected at nearby full-scale sites in Vancouver, BC, Canada. Moisture accumulation (measured by blotting on grass and by lysimetry) is found to be primarily controlled by nocturnal weather conditions and the intrinsic nature of each substrate, e.g. dewfall is abundant on nights with few clouds and light winds, and on surfaces such as grass and asphalt–shingle roofs, which cool rapidly after sunset. However, these responses are modified by location effects related to the net radiation balance of the surface, which itself is strongly linked to site geometry as expressed by sky view factor and whether surfaces are isolated from heat sources. The dominant mechanism is argued to be the systematic increase in longwave radiation loss that is associated with increased sky view. Results agree with those observed at the full scale and suggest that maps of sky view factor, and knowledge of dew at an open site, can potentially be used to create maps of dew distribution in urban and other complex environments. Copyright © 2002 Royal Meteorological Society.

The Reconstruction of the American Urban Landscape in the Twentieth Century

Abstract: One of the most important representations of an urban spatial structure is its density. Indeed, an urban area is defined as a densely populated place with a sizeable number of inhabitants. Yet, despite the fact that the defining element of an urban area is its density, few scholars have systematically examined the long-run changes in the densities of economic activities in these areas. This paper documents the historical changes in population and employment densities in U.S. cities and metropolitan areas and explores the causes of their rise and decline between the late nineteenth and the twentieth centuries.

Megacities and the environment.

Abstract: The world’s 25 largest cities comprise only 4% of the global population, but they have substantial impacts on the environment at multiple scales. Here we review what is known of the biogeochemistry of these megacities. Climatic, demographic, and economic data show no patterns across cities, save that wealthier cities have lower growth rates. The flows of water, fuels, construction materials, and food are examined where data are available. Water, which by mass dwarfs the other inputs, is not retained in urban systems, whereas construction materials and food predominate in the urban infrastructure and the waste stream. Fuels are transformed into chemical wastes that have the most far-reaching and global impacts. The effects of megacity resource consumption on geologic, hydrologic, atmospheric, and ecological processes are explored at local, regional, and global scales. We put forth the concepts of urban metabolism and urban succession as organizing concepts for data collection, analysis, and synthesis on urban systems. We conclude that megacities are not the final stage of urban evolution; rather, the climax of urban development will occur at a global scale when human society is at steady state with resource supply rates.

Analysis of land use/cover driving forces in the urban fringe of beijing city

Abstract: Drastic land use/cover changes have always taken place in the urban fringe area in the urbanization, which always aroused many environmental and ecological problems, such as pollution, biodiversity loss, local climate change and so on Thus, with the support of RS data and field investigation data, the driving forces of the land use/cover change in the urban fringe area of the west part of Beijing city is analyzed and evaluated in this paper The results show that the land use/cover changes in the urban fringe are affected collectively by many factors in different scales Human activity changed the landscape characteristics of the fringe as a whole and the rapid economic increase and fast urbanization were the key driving forces of the land use/cover change in the urban fringe area In addition, the investment and industry transformation of the urban area and the structure adjustment in the primary industry of the rural area drove the land use/cover change directly in the regional scale and the location factors such as traffic situations, landform and so on, affected the land use/cover change in the urban fringe in the local scale Besides, human behaviors also affect the land use/cover changes in the urban fringe in some extent

Urban agriculture between allotment and market gardening: contributions to the sustainability of African and Asian cities

Abstract: Due to severe competition for urban space from economically and politically much stronger fimctions, agricultural production is not considered sustainable in urban areas, Nevertheless, it is found all over the world and plays many different roles, including the supply of fresh food and flowers, a meaningful way of spending leisure time and supplementary income for many of the urban poor in third-world cities, Other roles are the management of green space or temporarily vacant land in cities at very low cost to the local authorities, and the recycling of organic waste. Drawing from a number of case studies in Africa and SE Asia, the present paper shows how difficult it is to play such valuable roles in the face of both imagined and real problems of public health or environmental degradation. At the same time, these urban agricultural producers may have to depend on polluted streams for irrigation, they may cause soil erosion by inappropriate farming techniques, or they may poison surrounding urban residents through the pesticides they apply. The paper describes how these synergies and conflicts result in a form of land use that could be much more beneficial to the urban system if it were treated by town planners and administrators as a normal urban function in need of both regulation and protection.

Urban flows in the HuNingHang Urban Compact District

Abstract: Urban flows are deeply influenced by third industry,i.e. third industry hold leading position in the role of linkages of urban compact districts. This paper discusses the urban flows in the HuNingHang Urban Compact District. The direction of intensifying urban flows of this region is that Shanghai should improve its comprehensive service capacities,it is more imminent to intensify overall strength for Nanjing,Hangzhou and Ningbo,and Wuxi,Changzhou and Suzhou should vigorously increase overall strength along with improving their comprehensive service capacities.

R/s analysis of urbanization effect on climate in lanzhou

Abstract: Based on R/S analysis and comparison between city and suburb, climate characteristic in Lanzhou city, Gansu Province was studied, the influences of urbanization on several climate elements in different season were calculated and the future trends of climate in Lanzhou were forecasted. The main conclusions are: (1) In the past 49 years, the long climate trend of Lanzhou city was consistent with that of Northwest China, the whole country and the Northern Hemisphere, the winter temperature and the annually mean temperature were ascending at the rate of 0.72℃/10-year and 0.28℃/10-year respectively, and the summer mean temperature was descending at a rate of 0.036℃/10-year. (2) The mean temperature, water vapour pressure, relative humidity and sunshine percentage in winter(January), summer(July) and annual mean from 1951 to 1999 in Lanzhou city and Jingyuan county were analyzed. The Hurst exponents of all the elements are beyond 0.5, which indicates that all the elements have evident Hurst phenomena. The results show that climate changes in Lanzhou city have a trend component, i.e. urban climate was warming up continually in the past 49 years. (3) In general, the Hurst exponents in winter and annual mean are much larger than those in summer, which indicates that the urbanization effects on climate are more powerful in winter than that in summer. (4) The Hurst exponents of different climate elements are sorted descendingly as: H(sunshine percentage), H(temperature), H(relative humidity), H(water vapour pressure), which indicates that with the limitation of meteorological and landform condition, the developments of industry and economy have much stronger influence on sunshine and temperature than that on humidity and water vapour pressure.

ŞEHİRLEŞMENİN KÜRESEL İKLİM SAPMALARI VE TAŞKINLAR ÜZERİNDEKİ ETKİSİ The Effects of urbanization on the Climate Change and Floods

Abstract: World population is increasing rapidly; reaching to seven-billion. Parallel to this urban population has also increased rapidly, exceeding threebillion, which makes 47% of the population. In our country this rate is about 65% and in western European countries it is 80%. Since 1975, number if urban cities and urban population has increased more than two times. By 2015 it is expected that %54 of the world population will be living in urban areas, and the number of metropolitan cities will increase to 36. Especially, abnormal increase in urbanization has caused climate changes/shifts, and consequently, increased the number of floods and their effectiveness. As a result of urbanization and concretization surface flows are increasing, and infiltration and underground water levels are decreasing. Equivalent to this, surface flows cause immense damages, as they are the source for floods. Furthermore, heat

Defining the pattern of the sustainable urban region

Abstract: Past efforts to define, describe, and advocate the spatial pattern of sustainable cities and towns have rested largely on the urban core, However, discussion of the relative effects of sprawl and sustainable development patterns must rest on a regional perspective since sprawl, by definition, includes land area other than the traditional urban core, Continued focus on the urban core has neglected the critical interaction of urban, suburban and rural land use patterns which is necessary for a comprehensive understanding of the regional system, In order to assess the relative resource efficiency of various urbankegional land use patterns, this paper explores the link between spatial form and land cover pattern of urban regions, and their levels of resource efficiency. A typology of regional form is developed, which leads to a framework for regional sustainability assessment, The secondary key to advancing this investigation is the development of a series of indicators that bridge the acknowledged boundaries of political divisions, watershed boundaries, and transportation systems.

Chapter 1 Urban air quality

Abstract: Since 1950 the world population has more than doubled, and the global number of cars has increased by a factor of 10 In the same period the fraction of people living in urban areas has increased by a factor of 4 In year 2000 this will amount to nearly half of the world population About 20 urban regions will each have populations above 10 million people Seen over longer periods, pollution in major cities tends to increase during the built up phase, they pass through a maximum and are then again reduced, as abatement strategies are developed In the industrialised western world urbn air pollution is in some respects in the last stage with effectively reduce levels of sulphur dioxide and soot In recent decades however, the increasing traffic has switched the attention to nitrogen oxides, organic compounds and small particles In some cities photochemical air pollution is an important urban problem, but in the northern part of Europe it is a large-scale phenomenon, with ozone levels in urban streets being normally lower than in rural areas Cities in Eastern Europe have been (and in many cases still are) heavily polluted After the recent political upheaval, followed by a temporary recession and a subsequent introduction of new technologies, the situation appears to improve However, the rising number of private cars is an emerging problem In most developing countries the rapid urbanisation has so far resulted in uncontrolled growth and deteriorating environment Air pollution levels are here still rising on many fronts Apart from being sources of local air pollution, urban activities are significant contributors to transboundary pollution and to the rising global concentrations of greenhouse gasses Attempts to solve urban problems by introducing cleaner, more energy-efficient technologies will generally have a beneficial impact on these large-scale problems Attempts based on city planning with a spreading of the activities, on the other hand, may generate more traffic and may thus have the opposite effect

Modelling studies of wind field on urban environment

Abstract: . Increasing load of air pollution in urban environment emphasises the need for detailed evaluation of wind characteristics that significantly affect the air quality of urban areas, especially, in large agglomerations. This paper includes analysis of urban wind climatology and estimation of wind profiles based on measurements of the new urban climate station located at the Eotvos University, observations of the meteorological station network of the Budapest agglomeration area, and multi-level wind measurements near Hegyhatsal. Furthermore, wind field modelling (using the WAsP linear spectral wind flow model) is presented over selected representative complex areas that demonstrates strong dependence between wind, height, topography, and roughness.

Multi-Agent Simulations as a tool for the assessment of urban microclimate and its effect on pedestrian behaviour

Abstract: The urban canopy layer is characterised by a specific climate which significantly differs from the average regional climate conditions. Especially inside urban structures such as street canyons, shopping malls or public places, the local microclimate depends directly on the physical properties of the surrounding surfaces and objects, producing well-known effects such as wind speed decrease, local jets, increased turbulence or increased thermal loads. These phenomena can have a strong influence on the comfort of pedestrians using these areas for different tasks of urban life or leisure activities. Assessing urban climate means to answer the question, how the citizens feel under the given circumstances and to decide, whether the urban design, the usage of urban structures and the needs of the pedestrians fit together or not. This complex assessment process requires a queue of different methods starting with numerical climate models that provide the meteorological parameters ending up with a set of models that simulate the comfort level or the behaviour of citizens acting inside the structure. In this paper, the Multi-Agent model climBOT is presented which aims to simulate the interactions between local climate and pedestrian behaviour. The different modules needed for that task are outlined and the general perception-decision approach for the agents is shown.

Rural-urban interdependency and the future of agriculture

Abstract: In January of this year, in his Condition of the State Address, Governor Tom Vilsack of Iowa expressed concern about rural Iowans being pitted against urban Iowans. He said, “We cannot afford to be two Iowas. We are and we must be one Iowa (Vilsack, 2002).” An editorial in The Des Moines Register followed up Vilsack’s comments by saying, “The existence of two Iowas – rural and urban – whose people do not recognize their common interests is the single biggest constant in Iowa politics (Doak, 2002).” Since moving to Iowa approximately two years ago from Seattle I have collected a folder of news articles and commentaries on this challenging and sometimes inflammatory issue. Here are a few examples of the topics from the Iowa folder: the costs of urban sprawl; the loss of the richest farmland in the world to development; a plea for regional land use planning to spread the costs of rural and urban services, the digital divide between rural and urban communities; the environmental and social costs of industrial agriculture and the decoupling of society from nature; the rural-urban split over local options sales tax for rural schools; fertilizer, sewage and manure contamination of lakes and streams; need for a state food policy to support locally grown food for urban consumers; a year-round farmers’ market to bridge the rural-urban divide; community opposition to factory farms; and the amazing growth of suburbs and villages within commuting distance of city jobs. As I reviewed these in preparation for this presentation, I found that my Iowa folder was not too different from the folder I had created during my years in Seattle! These issues are clearly subjects of concern across different regions of the country.

A Study on the Spatial Process for the Evolution of Urban Agglomerations and Optimal Land Use

Abstract: The evolution of urban agglomerations includes many contents, such as population, industry, type of cities, function of cities and so on. The most comprehensive and direct expression that urban agglomerations evolve is spatial process. Urban agglomerations can be divided into three layers, namely, primacy urban belt, growth belt of urban group, and hinterland belt of urban agglomerations. The evolution of the structure follows the laws of urban growth and regional economic development. The spatial dispersion of urbanization is the beginning of spatial spreading about urban agglomerations. The spreading of urban agglomerations has four phrases, namely, the expanding phrase of multi-central cities, the directional sprawl phrase of urban space, the centripetal and centrifugal phrase between cities, and the complex expanding phrase in urban agglomerations. Concentration of industries and evolvement of industrial structures are immediacy powers of spatial expansion of urban agglomeration. There has a close connection between urban development and land exploiture. Economic development brings about land exploiture, suburbanization and the growth of urban agglomerations promote land exploiture, and construction of developing region brings land exploiture. At the same time, urban spatial growth promotes land increment. This paper analyzes the spatial process for the evolution of urban agglomerations, studies its dynamic mechanism, and describes its basic features and regulars from the structure of urban agglomerations, space of urban agglomerations and land-use of cities. At last, the paper reveals the connections between the evolution of urban agglomerations and the changes of land use as well as its development trends. That are growth axis and expanding diversity (including type, speed and direction).