Remote Sensing of Land Cover Dynamics in Arid Steppe: Case of Algeria South-West

Abstract

Land cover change is the result of complex interactions between social and
environmental systems that evolved over a period of time. Climate and biophysical
phenomena have long been the main drivers of changes in land surfaces, but at present
the human induced activities govern most of changes affecting terrestrial ecosystem. The
investigation aims to study the distribution pattern of plants groups that constitute the
ecosystem typical of west Algeria and their dynamics as well as to assess method to
monitor the degradation process and capability of a system to protect areas earmarked
for plant and animal species. The Landsat satellite images were used for maping the
vegetation of the study area at a scale of 1:200,000. The changes were assessed based
on the maps obtained from satellite images (Landsat 8) of 2014 and of 1987 (Landsat
5). The results revealed strong decrease in the area of land occupied by steppe of Stipa
tenacissima and steppe of Artimesia herba-alba, which was replaced by three taxa Thymelaea
microphylla, Salsola vermiculata and Peganum harmala. Steppe of Artemisia herba alba has
been reinstated by steppe of Thymelaea microphylla, Salsola vermiculata and Lygeum spartum.
Woody species such as Quercus ilex and Juniperus phoenicea are also characterized and studied.