Iran is an arid country, perhaps it seems more like stating the obvious. However, this arid weather is the reason behind so many deserts in the country. A great percentage of the lands in Iran are arid or semiarid based on their average rainfall. Here, we would like to talk about what this terminology means, what it means exactly to be an arid country. Then, we will talk about the desert and their related terminology in Iran to have a more general idea about them.
What is an Arid Area?
Simply put, any region with an average rainfall of below 500 mm a year is arid. These regions may belong to one of the following four categories of semi-arid, arid, semi-dry, and dry with the semi-dry having the most average rainfall and arid the least. The average rainfall in these areas are:
- Semi-dry: 250 to 450 mm
- Dry: 100 to 250 mm
- Semiarid: 50 to 100 mm
- Arid: less than 50 mm
The arid areas may be extremely arid with 20 to 50 mm average rainfall, or hyper-arid with less than 20mm rainfall.
What is a Desert?
The arid areas with less than 50 mm of average rainfall are deserts. These areas lack vegetation and animal life, or at least very scarce flora and fauna. The term used to refer to such an area in Farsi is Biaban. It is a vast term that can cover any land with few to no plant and animal life.
Since the term is very broad and there exist many different forms of these lands, categorization is in order. Based on different criteria, deserts have different categories. For example, based on the nature of their origin they may be natural or human-made, based on the reason of their existence they may be climatic or pedologic, and based on their location they may be inland or coastal.
Kavir, Biaban, and Desert
After going through what the word Biaban means, we come to another term in Farsi or Kavir. Although the word is translated in English as desert, however, it is different from the arid land that we defined and termed as Biaban. Interestingly, many are not aware of the difference even in Iran and use the words as equivalent to one another, however, they are definitely different. In fact, Kavir is the driest part of the Biaban. Where Biaban has scarce plant and animal life, Kavir absolutely lacks any.
As mentioned, Kavir is the driest part of Biaban. But it also is the lowest part of it. Here is what happens, since this part of Biaban is the lowest, the seasonal showers and flood washes the salt and brings it to the lower land making the soil so rich in salt that no plant can grow in it. There is also the high evaporation rate which increases the amount of salt in the soil.
With this definition in mind, now its easier to understand that the desert of Lut, as the most famous desert of Iran, where the highest recording temperature was witnessed, is in fact the Kavir of Lut. Read more about Lut here.