ASPECTS OF THE VARIATION IN SOME CHARACTERISTICS OF RADIATION BUDGET WITHIN THE URBAN CANOPY OF IBADAN

Inadvertent modification of climate is at various levels. The aspect of the effect of urbanization on climate is a crucial one. Cognizant of the direct effect of climatic modification on human health, human comfort and energy use, and the dearth of information on climatic parameters in urban areas of the tropical cities, this study was initiated to examine the variation of some aspects of radiation budget in Ibadan. Basic information is given about the state of the urban textural characteristics. The data were collected in two ways, guided by the nature of urban characteristics. Firstly, urban-rural comparison of the characteristics of global radiation, albedo and net radiation was carried out by comparing information from a rural station with those from two urban stations. Secondly, automobile traverse surveys were conducted on different days across the major land uses from suburban locations. Only data on net radiation were collected during the auto-traverses. Results of investigation revealed that global radiation and albedo were less at the urban centres by an average of about 9-15% and 12-20%, respectively, while the net radiation was higher at the urban centres than at the rural station, by about 8-20%. Factors of urbanization like reduction in sky view, atmospheric pollution, change in surface texture, modification of wind characteristics as caused by urban artifacts, amongst others, were postulated as the major causes of the urban-rural difference in radiation budget. © 1989.