Urban Sprawl and Expansion of Road Networks and Its Impacts on the Environment Using Sensor and Socio-Economic Data: Macta Watershed, Western Algeria

Urban sprawl and the road networks have profoundly modified the space of the Macta watershed in western Algeria. The fragmentation of the landscape within this territory is gradually changing in order to meet different socio-economic needs. Damage to natural environments caused by pollution, business development, management of agricultural land and spatial modification of the morphology of urban constructions are remarkable. Our research is part of a complex study of the rate of evolution of urban sprawl and road networks expansion from 1987 to 2018; to better understand the issues of human activities and their impacts on the environment. The methodology adopted consists of using Landsat and Google-Pro images. Their capabilities enable us to trace the influence of human activities in time and space on the environment. The results obtained show a weak trend in urban sprawl during the period 1987/1998, while it reaches significant levels in the years 2010 and 2018. The distribution of the surface area occupied by towns and cities during this study period shows a concentration of the population in the major provinces. In addition, the extension of the East-West motorway shows a weak trend in 2018. The lengths of the roads built are significant and show a 50 % growth rate. The digital analysis using sensor data has an important advantage in detecting the evolution and progression of the spaces occupied by urbanization and road networks in the Macta watershed over 31 years, which has been marked by intense demographic growth.