期刊名称：American Journal of Geographic Information System
印刷版ISSN：2163-1131
电子版ISSN：2163-114X
出版年度：2017
卷号：6
期号：3
页码：111-127
DOI：10.5923/j.ajgis.20170603.04
语种：English
出版社：Scientific & Academic Publishing Co.
摘要：Despite postulations on the correlation between urbanisation rate, land use and land covers changes as well as sustainable urban development, majority of such correlations are descriptive. However, it is the quantitative models linking the same which have a niche in aiding the evolution of sustainable urban development strategies. This has to begin with spatio-temporal analysis of land uses, land covers and the detection of the temporal changes. The above being the case, this study analyzed the land use and cover changes for Nairobi at different epochs in order to detect the changes that have taken place and subsequently to predict the environmental implications of the same. The objectives of the study were to create a land use and land cover schema for Nairobi city for the period between the years 1988 to 2015, to quantify the nature, trend, rate of land use and land cover dynamics over the years, to establish the land consumption rate and land absorption coefficient trends for the city within the study period and to postulate the environmental implications of the changes. This study was aided by Digital Image Processing of multispectral Landsat TM imageries of the years 1988 and 1995, Landsat ETM+ imageries of the years 2000, 2005, 2010 and 2015 together with topographical maps of the city and other secondary information such as the city’s population for the years between 1988 and 2015. Unsupervised classification approach was used with accuracies ranging from 87% to 90%. The study establishes that while areas of the city under urban built-up, open and transitional areas as well as forest covers steadily increased during the study period, rangelands, agricultural, grass, secondary growth and riparian vegetations have declined. This is partially attributed to the population growth in the peri-urban areas which has led to land fragmentations to acreages which are not agriculturally viable thus the conversions of the agricultural lands to urban built-up users such as residential, industrial and commercial developments. This implies that the city has continued to experience increased Land Consumption Rate and Absorption Coefficient which confirms that as opposed to internal densification, the city’s growth has been characterised by urban sprawl.
关键词：Urbanisation;Land Use; Land Cover; Geospatial System and Environmental Quality
