Desalination

Desalination is the process of removing salt and other impurities from seawater to produce freshwater suitable for drinking, agriculture, or industry. Main methods include reverse osmosis (RO) and distillation (MSF, MED), with energy-efficient RO having become the mainstream method.

Persian Gulf oil states depend largely on desalination. Saudi Arabia's desalination capacity is among the world's largest, with UAE, Kuwait, Qatar, and Bahrain also relying heavily on desalinated water. These countries receive extremely low rainfall and have virtually no rivers.

Clues like 'depends on desalination' or 'extremely scarce freshwater' point toward Gulf states (Saudi Arabia, UAE, Kuwait, Qatar, Bahrain, Oman). Israel has also adopted desalination on a large scale.