Mountains

Terrace is shown because this helped keep a lot of rainwater in good use for farming. The terrace walls would help the water stay in the land and stop it from running off of the fields. 

Hollowed out tree. Shown because farmers used to store extra rainwater in a series of places including hollowed out trees.

This is supposed to be a riverbed down a mountain. That is being shown because ancient riverbeds that are on the mountain fill the sides of the mountain up with rain during rainstorms. 

The Indian Ocean. This is being shown because it always brings moisture to the mountains causing rain so it plays a roll in the environment.

Costal Plain

The dams and wells that were built lasted about 1000 years but in 580 C.E, the walls broke and obviously flooded.

The picture of the well/dam is shown because people built wells/dams all around to irrigate the land.

This picture is of a rocky cliff is shown because the Arabian Costal Plain ends in a series of rocky cliffs.

This picture of a Costal Plain is describing the environment itself

The oasis

The grass and shrubs are shown because Oasis' occurs "where fresh water is available." Plants, shrubs and grass all need water in order to survive. Somewhere that contains a lot of water will have plants.

The large areas of land is the Oasis itself. This are of land has a lot of land/water for plants and vegetation. It is very fertile land.

The water for the vegetation is shown because it was said that Nomads went from oasis to oasis on a thrive for water.

The dates and peaches are shown here because Oasis dwellers often grew fruits like the dates and peaches.