The plains formed when the slopes of mountains are worn back in arid and semi-arid regions by mechanical weathering is called

The plains formed when the slopes of mountains are worn back in arid and semi-arid regions by mechanical weathering is called pediplains. Pediplains are formed due to the process of mechanical weathering, which involves the physical breakdown of rocks into smaller pieces. In arid and semi-arid regions, the weathering process is accelerated due to the lack of vegetation cover, which protects the rocks from weathering. As the mountains are subjected to mechanical weathering, the loose rock material accumulates at the base of the slopes, forming a gentle slope or a flat plain known as pediplains. These plains have a gently sloping surface and are characterized by a thin layer of soil and gravel. Pediplains are commonly found in arid and semi-arid regions such as the deserts of the southwestern United States and the Sahara Desert in Africa. They are important for agriculture and grazing as they provide a large, flat area for farming and animal husbandry. In summary, pediplains are formed when the slopes of mountains are worn back in arid and semi-arid regions by mechanical weathering. They have a gently sloping surface and are important for agriculture and grazing.