The landform that marks the southern boundary of the Sahara Desert is the Sahel. This semi-arid region serves as a transition zone between the arid Sahara to the north and the more fertile regions to the south. The Sahel experiences a distinct wet and dry season, supporting various ecosystems, agriculture, and pastoralism. It is essential for the livelihood of millions of people who rely on its natural resources and contributes to significant challenges related to climate change and desertification.