The Analysis Of Temperature Field Effect About Different Underlying Surface In Harbin

With the acceleration of global urbanization and industrialization, the problem ofurban heat island has greatly impact on the city’s ecological environment and residents’daily life. This problem is concerned greatly by government and academia around theworld. Therefor, it is important to study the problem of urban heat island, the result ofthe study can guide the people to plan the city, to warn the city, to develop the urbaneconomic and to be healthy for the residents.This paper takes Harbin city in the south of Songhua River as study area, usingmono-window algorithm retrieves land surface temperature in September1989、2001、2007，in April2007and in June2007.Combined with the topographic map in1990s, thetemperature differences, the spatial and temporal changes of different underlying typesare analyzed in Harbin, then take road system and landscape park for example, studiesthe effect of different underlying surfaces on urban heat island, the results can alsoprovide theoretical basis and reference for Harbin in city construction and road planning.The details are as following:(1) Comparing with the surface temperature field in September1989、2001、2007,we found that urban heat island effect is very obvious. High temperature zones show thetrend of contiguous distribution in1989, while the scope of high temperature zonesexpand largely and the trend of distribution disperse to surrounding area in2001, thehigh temperature zones expand more significantly and become strengthen in2007.Onthe whole, the distribution and spread of high temperature zones are basically consistentwith the direction of urban built-up area, and they become severe with the developmentof Harbin city, at the same time, the temperature of the city decrease from the core areato suburbs(2) When contrast with the temperature field in three seasons in2007, we found thatthere is different levels of urban heat island effect in spring, summer, and autumn,while the result shows that the effect is strongest in summer, the following is inautumn, the weakest is in spring, and the distribution of high temperature zones arealso basically the same with urban built-up area. The area of different temperaturezones is changing significantly in different seasons, while the area changes a little inspring and in summer, when the area of high temperature zone and low temperaturezone increase largely, the normal area reduce greatly in autumn.(3) The types of city’s underlying surface are closely related to the occurrence and intensity of urban heat island effect. The results show that the temperature of roads,squares and residential areas is obviously higher than forest, grass, and water, while thetemperature of squares and roads is a little higher than residential areas, at the meanwhile the temperature of grass is also higher than forest and water. In summary, thetemperature of different surface types is squares>roads>residential areas>grassland>forest>water. There is a significant difference between the temperature of roads,squares, residential areas and forest, grass, water, and there is no obvious differencebetween impervious ground and natural surface, further more there is also distinctdifference about every surface type in each two seasons.(4) The city’s transport system has an impact on the surface temperature and urbanheat island effect. There is significant difference between rail roads and highways, railroads can rise the temperature of surrounding area and strengthen the effect of urbanheat island, highways as a corridor system can alleviate or separate urban heat island.While the effect of rail roads to surrounding area is no more than300meters, thecooling effect of highways is no more than0.4℃and the effect become lower and lowerafter the range of120meters. There is also showed the result that highways withdifferent greening level have impact on the urban heat island.(4) Landscape Park also has a significant impact on surface temperature and urbanheat island. Landscape Park can lower the temperature of surrounding area, and thiseffect decrease significantly with the increase of distance. There is obvious difference ofparks’ area to surrounding environment in120m, and the cooling effect is differentsignificantly with the changing of distance. Further more, there exists a significantnegative correlation between parks’ area and the internal temperature, that means thelarger the parks’ area, the lower the internal temperature is, at the mean while there isalso a significant regression relationship of them. Therefore, we can design parks withdifferent area to reduce the effect of high temperature zones.