Spatial And Temporal Change And Ecosystem Service Response Of Urban Green Space In Beijing City

As an integral part of urban landscape, green space plays an important role in urban development and construction. The temporal and spatial change of urban green space is a result of natural and human factors, is also an important symbol of the urban environment and living standards. How to use of limited land resources to realize the rational distribution of green space, optimize the structure of green space in order to play its ecological benefits and the use of function fully and efficiently is a very important issue.In this study, by integrated use of multi-source data such as remote sensing images, socio-economic statistics, survey and measured data, analyse of information extraction method, the temporal and spatial evolution of landscape pattern, ecological service functions Response to the rationalization proposals for future afforestation plan. The following conclusions:studies have shown that the threshold method based comprehensive index has higher classification accuracy compared to traditional supervised classification based on the original spectrum and has better classification results, while avoiding the redundancy of the data, it is a simple and effective method of information extraction; Vegetataion cover extraction based on linear spectral model able to further improve the classification accuracy, at the same time, through upscaling the distribution and function of of urban green space in different scales can be better reflected.the total of urban green space showed a decreasing trend in the past two decades (1989-2009), three temporal ratio of green space are41.57%,35.73%and26.89%, the reduction of green space is mainly concentrated in the urban fringe, the city greenbelt have been occupied by construction land, the mosaic structure of green space have been damaged, mainly caused by urban sprawl, at the same time green space increased slightly in urban center region. In accordance with the characteristics and classification of urban green space ecological service function, this study chose fixing carbon and releasing oxygen function, dust smoke pollution, water and soil conservation function, social function of several key indicators to build the ecosystem services evaluation system of urban green space.as an main type of green space, city parks layout is not quite reasonable, the city center is the lack of "green heart", City park space diversity is not good and landscape fragmentation is high, especially small plaque serious impact by human beings. â…£.By retreving of land surface temperature (LST) in Beijing city, it can be seen a significant difference LST in the difference surfaces. The average value of LST in urban significantly higher than that in suburbs, green space relatively has low temperature, LST and normolize difference vegetation index (NDVI) was negatively correlated. the urban heat island effect have been enhanced in Beijing from1989to2009with the cities expansion, the internal structure and functional morphology of the heat island has also undergone great changes, the center of thermal heat island has been further decomposition and evolution.