Study On The Landscape Pattern Change And Urban Heat Island In LAN Zhou

Urbanization is the trend of social development. In order to meet the needs of urban construction, more and more people gathered to the city in the process of urban development. With the increase in population and the change in underlying surface that cause a series of ecological environment problems in city, these problems have become the bottleneck for the further development of the city. Such as Lanzhou city, the mountains around in the North and the South and topography is complex in the East and the West of Lanzhou city, urban expansion is extremely difficult and ecological problems caused in the process of urbanization has become an increasingly serious. So studying the potential ecological effects of urban landscape pattern change is very significant to understand the change trend of city environment.In this paper, take landscape pattern and ecological environment effect of Lanzhou city. as the research object, use the theories of geography, ecology, landscape and urban landscape, selects the 1994~2013 satellite remote sensing image data of Lanzhou, the extract of urban landscape factors, the selection of landscape index, quantitative analysis the variation characteristics of urban landscape pattern base on GIS technology, spatial statistics and remote sensing technique; use visible light and thermal infrared band data, extracting influence factor of heat island effect, analysis change the trend of urban landscape pattern changes caused by the urban heat island, and provide a theoretical basis for people to improve living environment and urban planning.The main work and conclusions are as follows:1. Analysis Changes of landscape pattern in LanzhouData from Landsat TM/ETM+ images of different four years, extract category information of the urban, make the current land using map, statistical analysis was done on the area of the spot type analysis change characteristic of the land in whole city, with the characteristics of type, and select the landscape index, analysis of the changes of landscape pattern of city. The conclusion is the expansion which the landscape pattern of Lanzhou has undergone tremendous changes, the degree of landscape type diversity, the complex of spatial structure, the balance of spatial distribution and the fragmentation of landscape become serious.2. Inversion the land surface temperature and analysis the resultsUse Landsat TM/ETM+ images of visible and thermal infrared band data which are dealt with of radiometric calibration, geometric correction, atmospheric correction and other related processes, calculate vegetation index and the sixth band thermal infrared data; estimate the three parameters of mono window algorithm, which are surface radiance, the ratio of atmospheric transmittance and the atmospheric average effect of temperature; using mono window algorithm theory, according to the equations of transmission way to calculate the surface temperature in each period, analysis the change trend of temperature. The result is the temperature of central area in city was significantly higher than that of the surrounding area, city heat island formation obviously, and with the city urbanization intensifies scope change.3. Analysis influence factor of the urban heat island effectHeat island effect is the result of interaction is multiple factors interaction which mainly affected by the change of urban landscape pattern scale expanding, the proportion of through the urban landscape elements is more and more big, urban green land and water area decreased year by year, the change in urban land cover make the water of land surface and atmosphere, and material even energy exchange here changed,weaken the heat transfer capacity, urban heat only into the air, forming thermal environment effect and urban heat island effect.