10.3
Evaluating the status of inadvertent weather modification over decades in Nigeria
Juddy Ngozi Okpara, IKEJA, Lagos, Nigeria
In quest for economic development to alleviate poverty and uplift the living standard of the people over decades, humans has modified the weather both intentionally and unintentionally. It is in this premise that this paper undertakes to evaluate the different activities of man across the country which include agricultural land use practices, the urbanisation processes, widespread vegetative burning and biometeorological activities, which has significant impact on meteorological parameters, air-quality and climatological mechanisms which today influences man's health and productivity. Results showed that in the southern Nigeria, out of the gazette forest reserved areas of 464, 666 hectares, over 56,234 hectares of the areas has become deserved, resulting from agricultural land use. Also, over a total of 16,905 hectares of land areas across the country has experienced widespread vegetative burning and notably overgrazing, particularly in the northern part of the country; hence destroying many tree crops and forest which could have served as carbon-dioxide sink and at the same time exposing our maginal land to climatic hazards.
Urbanization is a process that has changed the characteristics of the earth's surface and the chemistry of the atmosphere. The most obvious climatic manifestation of this urbanisation over the decades is the trend toward having higher air temperature over the city core called "heat island" The heat island intensity (HII) across the south western part of the country during the dry and wet season, was observed to be in the range of 2.5°c to 8.0°c and to 60°c respectively. The relative humidity was observed to be in the range of 7-8.2% and also exhibits an inverse relationship with the temperature filed. Moreso, precipitation was observed to be more in magnitude and in some areas less in frequency in the heat island than in the surrounding areas. Further result show that climatological factors such as temperature, relative humidity and wind speed influences the physiological sensation of the inhabitants comfort or discomfort; hence during the afternoon and evening hours, the inhabitants may suffer great discomfort and even high mortality among the old people and even animals, due to hot and humid weather of the cities; unless the present microclimatic modification of the land use is minimised through the use of air-conditioners and /shelterhelts.
Session 10, Urban heat islands
Wednesday, 16 August 2000, 4:15 PM-5:30 PM
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