Geo-Spatial Approach for Urban Green Space and Environmental Quality: a Case Study in Addis Ababa
No Thumbnail Available
Date
2015-06-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Cities have become more stressful due to poor environmental conditions triggered by anthropogenic pressure on the environment in an unsustainable manner. Because urban environment is not being utilized in a sustainable way, the quality of its environment is being compromised leading to deterioration in several environmental variables such as natural vegetation, climates, wetlands, and wildlife among many others. Depending on the rapid growth in structural developments, along with the increasing of human population, the natural appearance and quality of, cultural and social structures of the cities are being changed drastically. Timely and regular information on urban environmental quality (UEQ) is essential for urban planning. This thesis presents the potential application of urban green as an indicator of urban environmental quality changes in the city of Addis Ababa based on the indicators of natural parameters extracted from remotely sensed images and socioeconomic variables derived from census data. Physical environmental variables such as land-use/land-cover data, surface temperature, normalized difference vegetation index, and other transformed remote sensing variables were derived from the three Landsat images of 1986, 2000, and 2015. Socio-economic variables including population density of Addis Ababa Central Statistical Agency and greenhouse gas emission of 2012 data were used. Regression analysis, factor analysis and overlay analysis were performed after the two groups of variables were integrated, four factors were identified such as greenness, crowdedness, heat island, and greenhouse gas emission for interpretation. By assigning different weights to each of these factors, risk map was generated and the proportion to overall greenness based on UEQ indexes map was generated. The goal was to extract greenness as a measure of environmental quality change and these results point towards a deterioration in environmental quality in Addis Ababa Sub City of Addis_Ketema order between very high risk and high risk, Arada and Lideta high risk and risk, Kirkose within risk and marginal Gulele among moderate and least risk, Kolfe, Yeka, Nifas_Silke , Bole and Akaki_Kality sub cities belong to are very low risk during this period of evaluation (1986−2015). It is recommended that future studies should include more parameters to provide a holistic view of the changes in greenness of the city and to try to mitigate the adverse effects of development activities leading to crowdedness and depletion of greenness in the city.
Description
Keywords
NDVI, GIS, Landsat, Urban Green Space, Spatiotemporal Distribution