Analysis of the Urban Geometry’s Effects on Nocturnal Urban Heat Islands Using Remote Sensing and GIS (Case Study: Golestan town, District 22 of Tehran)

Oke’s model is one of the most successful models presented to simulate maximum nocturnal urban heat island’s intensity (UHI) based on the urban canyons’ aspect ratio parameter. The aspect ratio parameter is known as one of the indicators of urban geometry. Since this simulation requires various spatial and descriptive analyzes (especially topological analyzes), the use of geospatial information systems is inevitable. In this study, the efficiency of Oke’s model is evaluated using regression analysis and land surface temperature (LST) calculated from ASTER data and single-channel algorithm (SCA), and a local model is presented to simulate the maximum nocturnal urban heat island intensity of the area of study. The coefficient of determination and correlation calculated based on regression analysis are 0.74 and 0.86, respectively. These quantities show a relatively strong linear relationship between the urban geometry index and nocturnal urban heat island’s intensity and the significant effect of urban geometry on nocturnal urban heat island intensity. The root mean squared error (RMSE) and the mean absolute error (MAE) of the presented local model are ±0.80 and 0.67, respectively, showing the acceptable accuracy of the presented local model in simulation of UHI intensity. Two-variable regression analysis shows a greater effect of the height of buildings on UHI intensity’s changes compared to the width of the streets. The sign of the coefficients above shows this effect is increasing in terms of the height of the buildings and decreasing in terms of the width of the streets.