Road Type Of Remote Sensing And The Simulation Analysis Of The Impact Of Urban Thermal Environment

How developed traffic network is the important measure of a country’s economic development level. Roads are the basic structure of traffic network. In recent decades its construction quantity and scale have increased dramatically. Because the underlying surface material is impervious, it can rapid warming after absorbing a large amount of solar radiation, which results in the decrease of evaporative cooling effect greatly, makes the road surface temperature is much higher than atmospheric temperature and heating the atmosphere temperature, adding to the urban heat island effect. Based on the ArcGIS and ENVI- met simulation as the main technical means, this paper analysis the present situation of the thermal environment of the Nanhai district and the influence of road surface temperature factor, establish the standard model. The main work and conclusions are as follows:Through nearly 20 years nearly 11 points of land surface temperature inversion figures found that Nanhai district overall heat island effect increased year by year, began to spread outward from a central area; Nanhai district road of urban heat island contribution rate changed from 0.47% to 0.93%, the heat island intensity changed from 0.97 ℃ to 2.81 ℃, increasing contribution rate, road to the urban heat island intensity significantly increased; Due to the land properties on both sides of the road is different, which is the cause of heat source and cold source roads, cold source road cutting the urban thermal field, to avoid the spread of urban heat island. Northwest-southeast and southwest-northeast direction of the road is less impact on the surrounding environment; Northwest-southeast, southwest-northeast, north-south, east-west direction of the road impact on the surrounding temperature range between 50 ~ 100 m. when the distance is higher than 100 m, the impact rise gradually weakened.By ArcGIS statistical sampling of Nanhai district road, found that the same trend roads, temperature decrease with the increase of the width of the road. Get the mathematical model of urban road ventilation prediction, found the main factors influencing the average wind speed ratio of the road are the direction of the road and the width of the road.Through the establishment of the standard model, found that when the wind direction is consistent, road type is different, the average wind speed and wind speed ratio are slightly different. When the wind direction is different, road type is consistent, the average wind speed is different, and difference is between 0.25 m /s to 0.29 m /s. When the wind is 135 °, the average wind speed on the road is in the maximum. When the angle of direction wind is in [45 °, 90 °] range, road width has negative correlation with temperature, when the angle of direction wind is in [0 °, 45 °) range, road width has positive correlation with temperature. So when the angle of direction wind is in [45 °, 90 °] range, the road design should try to increase the width to reduce temperature, when the angle of direction wind is in [0 °, 45 °) range, the road design should try to reduce the width to reduce temperature which can cause canyon effect. Pavement material high reflectivity of the road, the air temperature is low, the surrounding building surface temperature is low, pavement material low reflectivity of road, the air temperature is high, the surrounding building surface temperature is a little higher, so when designing way try to choose the material of high reflectivity.