Final answer:
The situation in many oil-rich nations of the Middle East where they must import fresh water is mainly due to the lack of freshwater resources and the heavy demand on existing water supplies. The presence of underground aquifers, industrial irrigation, and population growth contribute to the water shortage.
Step-by-step explanation:
The situation in many oil-rich nations of the Middle East, where they must import fresh water, is mainly due to the lack of freshwater resources and the heavy demand on existing water supplies. One of the reasons is the presence of underground aquifers, which are not considered renewable and are being depleted at a faster rate as more countries tap into them. The use of water for industrial irrigation and population growth also contribute to the water shortage. These factors result in the need for importing fresh water.