Showing papers on "Urban climate published in 1968"

A Preliminary Examination of the Possible Effect of London's Urban Area on the Distribution of Thunder Rainfall 1951-60

Abstract: IN URBAN climatology there are few studies of the effects of built-up areas on the distribution of rainfall. This situation is a reflection of the overall 'comparative lack of literature on the climatic implications of the urban sprawl' (T.J. Chandler, 1965, p. I9). The main reason for the neglect of the problem of the effect of urban areas on rainfall is not difficult to find. It is a lack of sufficient data. Not many urban areas have a rain gauge network sufficiently dense to allow analysis of even one day's rainfall let alone attempt a study covering a longer period. There are examples of both approaches. M. Parry's analysis (I956) of the storm of 22 June 1951 over Reading and F. A. Barnes's analysis (I960) of the storm of i July I952 in the Midlands are two of the notable attempts at single storm study. S. A. Changnon's work (I96I) in Illinois together with E. C. Barrett's (1964) in Manchester exemplify the climatological approach to the urban rainfall problem. This present study, illustrating the effect of the London conurbation on the distribution of thunder rain, is also climatological in its approach. Thunder rainfall was chosen because the occurrence of thunder and lightning is restricted almost wholly to clouds of marked depth with high water content: thus any study of thunder rainfall is a study of rainfall formed in clouds predominantly caused by convective motions. The possibility that a built-up area could influence such convective motions was seen by R. E. Horton as early as I92I. He 'observed some thunderstorms over some cities, e.g. Albany, N.Y. and Providence, R.I., which originated immediately over the city and did not travel far outside their limits on days when there were no other adjacent thunderstorms' (Horton, I92I, p. I93). The London conurbation was chosen as the laboratory for this investigation for three reasons. First, a firm climatological foundation is provided by Chandler's study (I965) of London's urban climate. A quotation (p. 240) from the chapter on precipitation summarizes the approach to be taken in this present study: 'A satisfactory answer to ... questions about London's role in modifying local precipitation can be gained only by very detailed analysis of conditions in the light of the known meteorological processes and the periods required for their operation'. The 'known meteorological processes' form the second reason for choosing the London area. Much of our knowledge of cumulus and cumulonimbus convection and of some aspects of cloud physics has come from the project undertaken by workers at Imperial College, London, in the period I959-64. All their research was concerned with storm behaviour in south-east England and the processes elucidated in this project are relevant to the present study (K. A. Browning, 1962; Browning and F. H. Ludlam, 1962; Ludlam, I962, I963). The third reason for studying the London region is the availability of data, not only for the

Urban Land Policy

Abstract: DURING the last few years there has been a great deal of.excited discussion about the population \"explosion\" in India, rapid urbanization, physical degeneration of towns, the unbearable stresses and strains of urban life. The malaise has been deftly identified by the inte1lectual community, by social scientists, administrators, townplanners, engineers and a host of inquisitive people. A variety of solutions-preventive and curative-have been offered. Yet, some basic factors seem to have either been forgotten or ignored. For instance, the constitution, the laws and the inherent attitudes of the community which provide, in a sense, a somewhat inflexible frame of reference in regard to any comprehensive study of the problem have received scant attention. Piece-meal approaches do exist and these are often proferred as total answers. This paper would appear to be another specimen of that kind-in so far as it attempts to deal with one component of the remedy, if there be a remedy at all. It is felt,-:· however, that a proper juxtaposition of this component in the total picture may help fill a gap.

Emerging patterns of urban growth and travel

Abstract: NEW TRANSPORT NEEDS ARE DEVELOPING IN OUR URBAN TRANSPORTATION SYSTEM IN RESPONSE TO GROWTH AND CHANGES IN THE STRUCTURE OF EMPLOYMENT AND ITS INTRA-METROPOLITAN LOCATION, AS WELL AS THE RELATIVE SHIFT OF METROPOLITAN AREA POPULATION TO THE OUTSIDE CENTRAL PORTIONS OF METROPOLITAN AREAS. CHANGES IN URBAN TRAVEL PATTERNS, TRAVEL DEMAND, AUTO OWNERSHIP, TRAVEL MODE PREFERENCE, AND RAPID TRANSIT ARE DISCUSSED. THE DEMAND FOR URBAN FREEWAYS AND THE ROLE OF URBAN PASSENGER TRANSPORT IN THE ECONOMY ARE ANALYZED. FUTURE GROWTH PATTERNS ARE DISCUSSED. A CASE STUDY IS PRESENTED OF THE BOSTON REGIONAL AREA URBAN GROWTH AND CHANGES IN URBAN TRAVEL PATTERNS.