L’étalement urbain et les contraintes physiques et naturelles Cas d'étude : La ville de Bou Saâda

Abstract

For nearly half a century, urban sprawl, by its unprecedented scale, has profoundly changed the report of urban space and has led to the emergence of new urban forms. Built-up areas seem both diluting and fragmenting within expanding territories in a context of generalized mobility of all actors of the city. Urban sprawl has a more current issue, in a context of strong growth in territories that continue to be swallowed up by the frame. We are more concerned about a contemporary phenomenon that is causing problems every day, mostly in terms of transportation, pollution, congestion and destruction of farmlands. However, the city grew up to meet its own needs; it is spreading out, somehow because of a lack of land within its boundaries. Therefore, the boundary of the city is continuously postponed further and further. Urban sprawl, as a process of spatial extension of the city, reflects a process of a galloping urbanization; it also shows an urban development brand in Algeria since the 1970s expressed by an urban evolution of a particular type that breaks with conventional urbanization in post-independence years. Urban sprawl is manifested mainly by an eccentricity of new residential locations. In this context, the city of Bou Saâda has not escaped from these urban dynamics motivated by socio-economic driving forces, causing though an excessive spatial growth. The city of Bou Saâda is located in the foothills of the mountains of Ouled Nail of the Saharan Atlas, was found somehow established in a binding site. Subsequently, the morphological question of urban sprawl in the physical and natural environments has led our concern about this phenomenon. The compact city was formulated in response to the spread out. There is a broad consensus for a "good urban form" universally applicable, that makes it a compact city, dense, and continuous, which would be the best tool for reducing fuel consumption and GHG emissions. To this regard, our study seeks to understand the pushing dynamics of urbanization, taking into account the physical and natural environments to assess the binding interaction between the driving forces of contemporary urbanization, the physical and natural constraints presented by both site and situation; revealing also trends of the spatial growth, and optimizing an urban development more coherent and sustainable.