Landslide Risk and Urban Development: The Response of Ali Mendjeli to Constantine's Geological Challenges

Landslides are a significant global hazard, posing serious risks to both human life and infrastructure, particularly in regions with unstable geological conditions. In Constantine, Algeria, landslides have been a persistent challenge, severely impacting urban areas and creating significant challenges for city planning and development. As a response to these challenges, the city of Ali Mendjeli was established 15 kilometers south of Constantine. This relocation was driven by two primary factors: managing the city's growth to prevent uncontrolled expansion and addressing the frequent landslides and natural disasters that rendered many homes unsafe. Ali Mendjeli was selected for its flat terrain and elevated position, making it ideal for urban development. The city was designed to accommodate displaced residents, mitigate landslide risks, and manage urban sprawl. In Constantine, areas with slopes ranging from 10%-20% (accounting for 45.46% of landslides) and 5%-10% (32.10%) were particularly vulnerable, prompting the relocation of residents to Ali Mendjeli. Since its establishment, Ali Mendjeli's population has grown rapidly, from 64,483 in 2008 to 243,214 in 2020, highlighting the demand for housing and infrastructure. The city's development illustrates how landslide risks in Constantine influenced population growth, providing a safer environment for displaced residents and accommodating a growing population. To investigate the landslide phenomena in Constantine, we conducted field observations to assess impacted areas and mitigation efforts. This was supported by secondary data, including a literature review, statistical population data, the Master Plan for the Development and Urbanism of Ali Mendjeli, and relevant legislation from the Official Journal of the Algerian Republic (SGG). The development of Ali Mendjeli serves as a case study demonstrating how geological hazards like landslides shape urban expansion. It highlights the importance of urban planning in managing these risks and highlights the role of interdisciplinary collaboration in fostering safer, more stable communities.

Keywords: Landslide Risk, Geological Hazards, Urban Planning, Urban Resilience, Population Relocation, Population Growth, Algeria.