Coastal deserts are spread in eastern and western stripes with an uneven breadth from Goetra harbor in the east to Khuzestan in the southwest of Iran on the northern shores of the Oman Sea and the Persian Gulf. The greatest feature of these deserts, which is the most important factor in their separation from internal deserts, is the high relative humidity, especially in the warm season, due to its proximity to the Indian Ocean and wet winds in this area.
There are also dispersed deserts in the west and western center parts of Iran as well as in the south of the Zagros Mountains. Among these deserts, we can mention Meighan desert.
Meyghan Desert with 120 km area is located in the northeast of Arak, and has been expanding in recent years. In the eastern parts of it, there have been some actions to prevent the advent of the desert, and now its central parts are extracted from sodium sulfate. In the southern parts of the desert there are clay, silicate and sodium salts have formed hard and dense surfaces. Due to the effect of the process of evaporation of water from the bottom up, polygon forms are formed in the northwest of the desert due to the activity of the winds of the sand dunes.
In the Meighan desert, evaporation is less than the amount of water that enters the area and, as a result, creates a temporary lake. The surface of the desert is smooth and consists of soft and fine sediments and is the largest sediment of clay, which represents a wet climate in the past that mechanical and chemical degradation in the basin has caused the flow of water to it, and the southern is very hard and impenetrable because of sodium sulfate. Meighan desert has seasonal and annual variations In winter and spring, when the rain level is high, its surface is watered and turned into a lake, and in the summer it is covered with hard salt due to the strong evaporation of it and forms various forms of salt in desert level.