مدلی بـومی بـرای ارزیـابی تـوزیـع انـدازه‌شهـری‌در‌منـاطـق‌خشک

1- Introduction This paper presents a simple method for evaluation of the size distribution of urban of innovative models (base Zipf’s law). The case study is in arid areas (including the province of Yazd). Technically, the arid regions of the world include those located within the tundra belts, commonly referred to as cold deserts, and those located within the equatorial belts of the world, otherwise referred to as hot deserts. It seems the need for differentiation is responsible for introducing the term Arid Lands, which apply to those developable and habitable belts, mostly in desert and semi desert areas. According to Golany (1978), at least four major types can be identified, influenced by the latitude of the area, the distance from the sea, the absolute or relative elevation, and the topography and geomorphology. Somehow, the location of these deserts coincides with the location of most of the world’s underprivileged populations, particularly with regard to arable lands, natural resources, population structure and socioeconomic potentials. In most desert settlements, the challenges stem from extreme temperatures that are characterized by high diurnal ranges, shifting sand dunes and occasional sand storms. These areas are known to be drought ridden, subject to sporadic storms and floods beyond the capabilities of most makeshift or transient dwellings. Native model based on dividing the area prepared for the cities of Yazd province into six regions with the following criteria to the population of all cities, the population of the proposed offer. The model is based on indigenous, appropriate and effective recommendations for adjusting the size distribution of cities is given. they have suffered divine tribulation. Their relics in the depth of 12 m. of sand dunes in that region during Imam Kazem (AS) reign and in the end of the 20th century have been discovered. The next stage deals with the significance of geographical position of this region in Quran and attempts are made to convey the related messages. Of course, before mentioning why Quran calls A'ad region as Ahghaf, this issue is considered whether Ahghaf in the era when A'ad settled in that area have been given to this region or this name has been given to this region later. Hence, after expressing the comments on the more accurate comment, it can be said that Ahghaf (i.e. sand dunes) has been formed after the divine tribulation and happening some events on this region. However, it may be before this event sand dunes have existed in that region and this matter makes the tribulation through sands more logical. Therefore, it is obvious that God the Ahghaf has exemplified it as Ahghaf for our understanding to remind us of Kavir and sand desert to ask this question that how was this region that the God has mentioned it as Ahghaf. When through Quran and Archeological works and historical quotations referring to the geographical characteristics before divine tribulation, it can be understood that the difference of these two regions after seven days have increased and this is the chastisement for those people who have arrogantly and pride disobedient to God. Following to the elaboration of this topic dealing with this region and the Quranic messages gained from them. It is hoped that through presentation part of the efforts made by the Muslim geographers in various eras we can appreciate their attempts.