Decline of urban ecosystem of Mzab valley

摘要

Mzab settlements are a group of five towns implanted along the valley of Mzab in the south of Algeria. They were developed in response to site and climatic constraints and adjusted well to rational urbanization for many centuries. Traditional ways of adaptation to these conditions were based on ecosystem balance management and on efficient exploitation of natural resources. The sites are selected to assist defense, to benefit from summer breezes and to promote natural drainage, whilst providing shelter from the sun and adapting generally to severe local climate. Rapid growth and structural changes in the local economy, coupled with accelerated urbanization generated a variety of significant environmental problems such as perturbation of environmental hydrology, pollution and thermal discomfort. The impact of these problems upon the well-being of the inhabitants have become a major preoccupation. The most important aspect of Mzab structural characteristics is the transition from traditional into a modern structure and the observation of a fast transformation process from the economic sectors. A great deal has been written about history, architectural and town planning principles for Mzab settlements in Bouchair and Dupagne (Building Environ. (2003), to be published). However, much remains to be dealt with and elucidated concerning the ecosystem and ecological balance of the Mzab area. In this paper, we try to demonstrate the role of traditional practices for maintaining ecosystem balance and protecting natural environment in the Mzab valley. Also, discussed and analyzed are the degradation of traditional practices of environmental control and its implications upon the ecosystem balance and the thermal comfort for the inhabitants.