Changes in wind fields affected by urban development Case Study: Saadat Abad neighborhood of Tehran

Topography of Tehran, density and height of buildings, traffic, width and direction of the passages with the climate, play a major role in the accumulation of pollutants. One of atmospheric parameters in the dispersion of air pollutants in Tehran decisive is the wind. In this research, the behavior of the wind in the current situation has been investigated using descriptive-analytical and cross-comparison and simulation techniques by software Matt ENVI, which is a software to analyse the climate. Collecting data was through library and field studies. The results show that in the north-south streets (parallel to the prevailing wind direction), the majority of septic streets has increased wind speed. This results in the emission of these streets. In streets that are perpendicular to the prevailing wind direction (east-west streets), the effect of altitude and the proximity of buildings to each other, in addition to the change of direction and wind speed, will causes the published accumulation of pollutants on the street. Based on the results obtained from this study, north-south streets, especially Besat Street in the neighborhood of Saadat Abad, has the highest wind speed. One of the main reasons for the increase of wind speed on this street can be channeled and its width. High wind speeds on this street has an inverse relationship to the amount of carbon dioxide released. So that the least amount of carbon monoxide was found in the street