Evaluating the Geographical Distribution of Urban Populations in Coastal Provinces of Southern Iran Using the Passive Defense Approach

The current study makes use of the results of the census of 2016 in Iran to evaluate the geographical distribution of urban population in Khuzestan, Bushehr, Hormozgan, and Sistan and Baluchestan using the passive defense approach. The methodology of the study is a combination of documentary, descriptive, and analytical methods where the percentage of urban population of the capital city of the province is compared to the urban population of other cities in the province, and the rank-size law of Zipf along with the urban primacy index are used. The results show that Hormozgan Province with a population density of 55.90 percent of the urban population of the province in Bandar Abbas City has the worst state among the four selected provinces, followed by Sistan and aluchestan, Khuzestan, and Bushehr Provinces with the concentration of 44.07, 33.55, and 32.73 percent of their total populations in capital cities of Zahedan, Ahvaz, and Bushehr, respectively. Therefore, Bushehr Province has the best possible state among the selected provinces with regard to population distribution. Evaluating the urban primacy index for the selected provinces shows that Khuzestan, Hormozgan, and Sistan and Baluchestan Provinces are faced with the phenomenon of primate city and Bandar Abbas, Zahedan, and Ahvaz Cities are the primate cities in the urban network system of Hormozgan, Sistan and Baluchestan, and Khuzestan Provinces, respectively. Bushehr Province does not have a primate city. The results for the rank-size law model show that the urban population of cities in Khuzestan, Hormozgan, and Sistan and Baluchestan Provinces are far from the rank-size Zipf model, with the state of Hormozgan and Sistan and Baluchestan Provinces being worse than Khuzestan Province, while Bushehr Province does not suffer from the primate city phenomenon, thereby having a balance in its urban system. However, this type of balance follows the combinatory model, i.e.the urban hierarchy of Bushehr Province lacks the primate city phenomenon, but is not standard either; in other words, this province is at the middle of the spectrum. Based on the results from models comparing the urban population of the capital city of the province with the total population of the other cities in the province and the primate city model and the rank-size Zipf model, it can be concluded that the status of Hormozgan, Sistan and Baluchestan, Khuzestan, and Bushehr Provinces ranges from rank one (the worst case) to rank four (the best case), respectively. Therefore, Hormozgan, Sistan and Baluchestan, Khuzestan, and Bushehr provinces are respectively ranked from the worst to the best states with regards to following the principles of passive defense.