References Review Questions Regional Characteristics Defining characteristics for Southwest Asia are climate, culture, and oil. This region stretches throughout deserts, plateaus, and river valleys. Generally, its arid climates make it a part of the dry world, although the diverse physical geography causes the rain to vary greatly. Deserts, steppes, and mountains dominate the physical environment in Southwest Asia. Except for the Mediterranean coasts, this is a realm of very low and highly variable annual precipitation, of searing daytime heat and chilling nighttime cold, of strong winds and dust-laden air.
Soils are thin and mountain slopes support little vegetation.
Water brings exceptions to these conditions along the coasts, rivers, and in oases and qanats. Southwest Asia can best be summed up as a B climate, desert and steppe, with the Arabian Peninsula being the driest with an average rainfall of four inches a year. The land between the Tigris and Euphrates rivers is called Mesopotamia. This land is very fertile. The agricultural development influences villages far away from Mesopotamia.