How do bodies of water and river systems affect human activities in the Eastern Mediterranean

The Eastern Mediterranean region is a region that has mostly semi-arid and arid climate, dominated by steppes and deserts. There are no lot of bodies of water and rivers, but the ones that are there are crucial for the survival of the people living there. Since the climate is very harsh and doesn't allow for people to live in larger groups in the mainland, almost all people live around the bodies of water and the rivers. The reason for that is that the bodies of water and the rivers enable the people to produce food, to travel easily, to trade, connect with the rest of the world, and the waters themselves are a big source of food, and of course the most important factor - they provide drinking water.