I am a desert named after a historical queen, known for my shifting sand dunes and extreme temperatures. I border multiple countries and am home to nomadic peoples who have adapted to the harsh environment. My underground aquifer system is a crucial water source, but threatened by overuse. What desert am I?

1. My name is associated with a powerful female ruler of ancient times.
2. I am part of the world's largest hot desert system.
3. Nomadic groups like the Tuareg call me home.
4. I contain fossil aquifers, vital but vulnerable resources.