Contribution à l’étude spatio-temporelle des problèmes de dégradation de l’environnement en zone urbaine et péri-urbaine de Bujumbura : cas des sites de Kinama et Karama

Abstract

The main cause of environmental changes on a global scale is generally the intensification of human activities. Human always tries to cover his well-being by satisfying his needs. In order to achieve his goals, he must use the natural resources whose exploitation requires a conscious mind of future generations. Population growth causes directly an increased demand for natural resources and the expansion of cities. Cities are spread very widely, mixing with rural areas in a diffuse way, preventing a clear and coherent identification of the territory because of the infinite need for space. Urban sprawl is increasing in parallelism with a demand for construction materials, the exploitation of which generates risks of environmental degradation. The city of Bujumbura in Burundi has been growing since the end of the civil war in 2003 and new neighborhoods are springing up day by day after the clearing of agricultural areas and vegetation. It is therefore up to the scientist to make available tools that can help policy makers to remedy the consequent problems of this over-urbanization. For this purpose, a study was undertaken on two peripheral sites of the city of Bujumbura to study the problems of environmental degradation associated with the spatiotemporal dynamics of the two sites between the years 2005 and 2020. The two sites are Kinama located in the in the north of Bujumbura city and Karama, located in the northeast of the city at the foothills of Mumirwa. This is a site that was valued by quarry operators. The ETM 2005, 2010, and OLI-TIRS 2015, 2020 satellite images of the two sites were downloaded and processed by supervised classification in ArcGIS10.4.1. The results obtained showed a regression in the vegetation cover of 631.81 hectares for the Kinama site from 2005 to 2020, while the area covered by buildings increased by 575.58 hectares during this period. The uncovered surface has also increased what puts the site at risk of flooding. The same case was confirmed for the Karama site where the built up surface has increased by 203.84 hectares while the vegetation cover has regressed by 210.31 hectares, with a small regression of the bare surface in favor of the buildings. Our study has stressed the demographic explosion which generates the increased demand for natural resources but also for surplus surfaces for housing. We have not forgotten the effects of climate change associated with human activities. Perspectives relating to the management of house building through the social housing policy, the effective management of births to control population growth and the Burundian population information in terms of environmental management have been issued in order to be able to contribute to the guarantee of a healthy environment.