The ventilation in the cities influences the urban climate being compromised with geoecological and georbana factors that modify the movement of the air resulting from the Regional Circulation. In the ventilation of cities, at local and urban level, the modifying elements related to topography and those resulting from urbanization are important. Cities, due to their structure, surface characteristics and heat island, exert mechanical and thermal influences on the air flow, generating a specific circulation proportional to its size. Studies carried out in the city of Santa Maria - RS, emphasize the influence of the site and the urban structure in the movement of the air and the knowledge of this own circulation is important as a subsidy to the decision making directed to urban planning
