Determination of climatological deserts in Iran

Many climatology scientist adopted temperature and precipitation among all climaticparameters to identify desert regions from non-desert areas. There is no one definition of a desert that is accepted by all. The boundaries of a desert change radically depend on the variance in the range of proposed criteria definition accepted. Thus this study was carried out to identify the boundaries of a desert territory from non-desert regions using climatic data such as total precipitation, average intensity of daily precipitation, annual average temperature and evaporation together with the coefficient of variance and seasonal concentration. For each climatic factor a digital map was produced for all studied provinces using Geographical Information System (GIS). By overlaying all digitized climatic factors a transitional strip of boundary was recognized and then its accuracy was checked with field data and topographic map. Based on this boundary strip, three zones were recognized as 1- true desert zone located inside the strip of boundary.2- non-desert area, outside of the boundary and 3-Semi-true desert zone located in the boundary strip itself. It was concluded that true or natural desert that known as climatology desert are 700991 km2 or 42.5 % of the Iran map.