Revealing the Physical Expansion and changes of heat islans in Minab City based on the contribution of Population factors and horizontal dispersion

The purpose of this study is to reveal the physical expansion and spatial changes of heat islands in Minab city during three time periods (1975-1988, 1988-2000, and 2000-2014). For this purpose, TM and OLI images of Landsat satellite were  used. The physical changes of the city were obtained by analyzing the values extracted from the two indices of normalized difference built (NDBI) and normalized difference vegetation (NDVI). To find heat islands of the city, single-channel and separate-window algorithms  and to investigate the contribution of population growth and urban horizontal growth on changes in heat islands, Shannon and Holdren entropy models were  used. The results showed that the maximum amount of physical expansion of the city happened 901.61 hectares, in the years 1988 to 2000 of which 55.6 percent was based on population growth and 44.4 percent was based on the incrae of land per capita. The area of the heat islands was estimated to be 112.96 hectares, indicating the north-south and east-west trend, which has grown more than 4 times compared to the previous period. The share of population factor in this growth was 62.8 hectares and the share of urban sprawl was 50.16 hectares. The Shannon’s entropy value was 0.3, indicating an unrestricted growth in the considered period. In general, in the 39-year period, a 5 fold increase in the size, a 6.34 fold increase in the population and a 5.7 fold increase in the heat islands area were observed in the Minab city. Since no documentary report has been presented regarding the investigation of heat islands in Minab city, the results of the present research can be used to manage the concentration of the city points.