Final answer:
The largest desert in Saudi Arabia covering much of its southern region is the Rub' al Khali or Empty Quarter, known for being both the largest contiguous sand desert in the world and extremely rich in oil reserves. Its extreme dryness and heat make it one of the least inhabited places on Earth.
Step-by-step explanation:
The largest desert in Saudi Arabia, which covers much of its southern region, is the Rub' al Khali, also known as the Empty Quarter. This desert comprises about 25 percent of Saudi Arabia's land area and is characterized by extremely dry and harsh conditions. Due to the scarcity of water, there are no natural lakes or major rivers, and agricultural productivity in the region is heavily dependent on alternative sources of water like rainfall, underground aquifers, oases, or the desalinization of seawater.
Recognized as the largest contiguous sand desert in the world, the Rub' al Khali spans across the southern region of the Arabian Peninsula and is notably rich in oil reserves. Despite its vast size and economic significance due to oil, it is one of the least inhabited regions due to its inhospitable environment. The intense heat and lack of water make it one of the hottest places on Earth, especially during the summer months when temperatures can exceed 120 °F.
While the Rub' al Khali is significant for its extreme desert conditions and oil production, it barely sustains the few local tribes that live in the region. The challenges presented by the climate and geography of the Empty Quarter highlight the critical importance of water as a valuable resource in the area, much more than the availability of oil.