Showing papers on "Urban climate published in 1984"

Studies of urban climates and air pollution in Switzerland

Abstract: In addition to an assessment of the factors that are responsible for urban climate change, this paper describes climatological studies and peculiarities of some Swiss cities. Although these cities are small, urban air pollution presents a real problem for urban planning. This is a result of the narrow street canyons, the high traffic concentration and the complex topography, which favors air stagnation during anticyclonic weather conditions. In recent studies of urban climate and air pollution, scientists have tried to find a balance not only between modeling and observational studies, but also between specialized investigations and integrating studies which lead to an application in land-use planning and politics. In almost every city, research efforts have concentrated on the dynamics of temperature stratification and airflow. Because of the smaller size of Swiss urban areas and the existence of a complex topography, the interactions between three effects important for transport and dispersion ...

Provincial variation of urbanization and urban primacy in China.

Abstract: Compared to other developing countries, China has a low urbanization level as a result of government policy to control urban development since 1949. However, there is much regional variation in urbanization and urban primacy among its 26 provinces. This paper attempts to analyze the provincial variation in urbanization and urban primacy of China in 1978 by factor analysis and regression techniques. In China, government policy does not only slow down the overall rate of urbanization but also has profound influence on provincial variation in urbanization and urban primacy. Low urban primacy in the eastern provinces is mainly the result of the urbanization policy of controlling the development of large cities that favours the development of small and medium cities. The spatial industrial policy of decentralizing industries from the coastal provinces to interior provinces encouraged high urbanization and urban primacy in the western interior provinces of China.

Urbanization in the windsor-quebec city axis, 1921-1981

Abstract: Between 1951 and 1971, population and economic activities appeared to be concentrating in the Windsor-Quebec City axis, and a consequence of this was rapid urban growth and the development of a highly interconnected urban corridor. Since 1971, some decentralization of economic activities and population away from the axis appears to have occurred, and the patterns of urban growth within the area are quite varied. In this paper, the 1921-81 fluctuations in concentration/ deconcentration are documented, recent particular geographic shifts are outlined, and a theoretical interpretation of the changes is discussed.

Trends and changes of the urban system in China.

Abstract: An analysis of trends in urbanization in China since 1949 is presented. The differences in the rates of growth of towns and cities in various parts of the country are considered and the relationship of these differences to economic development is discussed. A high rate of increase for urban areas is envisaged for the period up to 2000 and the fact that official policy intends this growth to be focused on smaller urban areas is noted. (ANNOTATION)

Characteristics of urbanization of China--changes and causes of urban population growth and distribution.

Abstract: The process of urbanization in China from 1949 to 1982 is described. The author notes that over this period the urban population increased from 57.6 to 139 million a rate of 2.79 percent per year. In comparison with other developing countries Chinas urbanization level is low. Fluctuations in the level of urbanization over time are noted and the reasons for them are discussed. The ability of China to implement effective policies controlling internal migration and in particular to reverse the flow of migration to urban areas is examined. (ANNOTATION)

Land-Use Changes in the Rural-Urban Fringe

Abstract: Land use in the rural-urban fringe is regulated by two zoning acts: the first is the Urban Planning Act, which is intended to divide urban planning area into an urbanization promotion area and an urbanization control area in order to restrict urban sprawl; the second is the Agriculture Promotion Act, which is intended to define agriculture promotion area within the urbanization control area in order to protect and promote agriculture by a strict management of land-use conversions. It is often said that these zoning acts have not achieved expected results. However, there have not been sufficient attempts to examine their achievements quantitatively. The aim of this paper is to establish quantitatively the patterns of land-use changes in the two contrasting zones of the rural-urban fringe, i. e. the urbanization promotion area and the urbanization control area, for an actual case.The area selected, which is about 20 square kilometers in size, occupies the southern part of Matsuzama City, and it is facing a hasty urbanization, with a rapid increase of population and large-scale land-use changes. This area includes both types of zone, i. e. an urbanization promotion area and an urbanization control area (including an agriculture promotion area). The author measured land-use changes in each zone on the land-use maps of 1971 and 1976 compiled by Matsuyama city office on a scale of 1 to 10, 000.The results of the investigation are as follows:(1) In the urbanization promotion area and the urbanization control area, land-use changes from rural (paddyfield, upland field, forest) to urban categories (housing, business and commerce, industry etc.) exceeded other types of change, and they amounted to sixty percent of the total land-use changes.(2) The diversification of land use during this period was shown in terms of the increase in the number of land uses extracted by Doi's method of land-use combination.(3) The area of land-use changes in the urbanization control area was about one third of that in the urbanization promotion area, but it still amounted to 3.5 percent of the former area. This means that although the zoning by the Urban Planning Act played certain role in the management of urban sprawl, it fell short of its original target.(4) In the urbanization promotion area, land-use changes between urban categories was about three times as much as in the urbanization control area, reflecting looser legal restrictions on these changes in the former. Land-use changes from rural to transitional categories (vacant land) were more evident in the urbanization control area, because large-scale projects, which were accompanied by many vacant lands during contstruction, were apt to be located in the urbanization control area.(5) In the urbanization promotion area, land-use changes were disorderly throughout the whole area, because land-use conversion was almost free in this area. On the other hand, land-use conversions were mainly located along trunk roads in the urbanization control area, due to the legal guidelines on the conversion of agricultual land.It may be concluded that there were clearly different patterns of land-use changes between the urbanization promotion area and the urbanization control area, and the zoning acts regulated patterns of conversion to some extent in the rural-urban fringe.

Site planning for natural ventilative cooling in urban areas within a warm humid climatic zone

Abstract: This project explores the creative use of wind in the design of building layouts under warm humid climatic conditions. The affects of microclimatic wind are an important criteria in architectural design and planning. Aerodynamicists and civil engineers have concentrated mainly on how wind affects structural design, and much less on the environmental effects of the wind. Indoor air movement is mainly governed by outdoor wind conditions. Quantitative studies of wind flow pattern around built form have been carried out recently relating the size and shape of structures or landscaping to the screening effect they have upon natural wind flow. The author has undertaken an intensive literature survey in the subject for the purpose of summarizing information of potential usefulness in the control of indoor urban climate through improved zoning regulations. In this context the author has also performed experimental observations, the results of which are compared with the results of other recent experimental observations. The resulting critical appraisals lead to recommendations for site planning layouts with a view to obtaining natural thermal comfort under warm humid climatic zones as are found in Calcutta, India. The final proposals are based on the environmental conditions of Calcutta. Three aspects of research are presented below : PART I : An introduction to the research project with objectives and goals. PART II : a) A brief description of the history of wind use. b) An analysis of contemporary uses of wind in the architectural setting. c) Literature survey of wind flow around built form and observations. PART III ; a) Experimental observations to establish correlations between wake geometry and built form. b) Analysis of microclimate around typical built forms for Calcutta, India. c) Recommendations for site planning in warm humid climatic zones such as Calcutta, India, with a view to obtaining natural thermal comfort. TABLE OF C O N T E N T S Page 1 IN T R O D U C T IO N 1 .1 P R O B L E M 1 1.2 OBJECTIVES & GOALS 3 2 L ITERATURE SURVEY 2.1 HISTORY OP WIND U S E 5 2.2 ANALYSIS OF HISTORICAL USES OF WIND IN THE ARCHITECTURAL SETTINGS . . . 7 2.3 WIND FLOW AROUND BUILT FORMS A) Wind Pressure on Buildings and its Effect on Internal Flows . . . . . . 12 B) B u i l d i n g 16 C) Wind Flow Interraction with Landscaping 40 2.4 EXPERIMENTAL TECHNIQUES A) Full-scale 46 B) Model-scale(Wind Tunnel) 43 C) Model-scale(Natural Wind) 53 3 E X P E R IM E N T A L S T U D IE S 3.1 RESULTS 5*3.2 RECOMMENDATIONS 35 4 A P P E N D IC E S 97 5 BIBLIOGRAPHY 114