Urban Land Use/Cover And Spatial Pattern Analysis

Urban land use/cover changes have impacts on urban surface charaicteristics, as well as the socio-economic developmemt. Therefore, it is important to analyze the urban land use/cover and spatial pattern changes. Taking Changsha city as a case study area, this paper studied the classification method of unban land use/cover and the analyzed landscape pattern gradient changes. The main conclusions are as follows:(1) Land Use/Cover Classification Using Remotely Sensed Surface Biophysical ParametersThe classification based on the spectrum reflectivity can not solve the phenomena of "the same kinds of targets with different spectral or the different kinds of targets with the same spectral". Therefore, the classification accuracy is not satisfied to analyze urban land use/cover change. This paper extracts four classification features including Vegetation Index (NDVI), land surface temperature (Ts), Temperature-Vegetation Angel (TVA) and Temperature-Vegetation Distance (TVD) for Maximun Likehood classification and decision tree classificaion. Compared several image processing routines, the results indicate that it has the highest classification accuracy combining NDVI and Ts and the multi- spectrum image for Maximun Likehood classification and decision tree classificaion. TVA,TVA and TVD that are used in the multi- spectrum image almost had no effect for improve the classification accuracy. Whereas, based on the multi-spectrum image, it has higher classification accuracy using NDVI, Ts, and TVD. In the process of decision tree classification, the spectrum of the types is mixed up in the bands of Ts,TVA,and TVD, and it can not distinguish the land use/cover types. Therefore, NDVI,TVA and TVD are used to joined in the classification. Its accurarcies are highter than the classification accuracy that only using Maximun Likehood classification.(2) The gradient analysis of urban landscape patternFirstly, land use/cover information for the four years is extracted based on the Landsat imagery. Then, landscape metrics combined with gradient anlysisis employed to analyze the spatial pattern changes of Changsha city. The results show thatâ‘ the mobile window that the radius is 0.5km may be more appropriate for unban landscapes pattern analysis. It avoids the great fluctuation of landscape metrics, and it can reflect the change rule of urban landscape gradient;â‘¡with the development of the urbanization process, In the class level, from the the center of the city to the edge, various landscape metrics reveral significant gradient variation according to the distance between the center of the city and the types of land use.In the landscape leve, low fragmentation and good connectedness is appeared in the center of the city. Beacause city, bare land, argriculture and forest exist in the outskirts, the landscape has high fragmentation, poor connectedness; the exurb is the area that its landscape pattern changes most. The nature landscape is disturbed, and its shape becomes more complex. Moreover, the high fragmentation also is appeared and the dominance of the landscape failed.(3) The relationship between the urbanization and the landcape patternLandscape patterns in four different years (1973, 1993, 1998 and 2001 year) are extracted using Landsat images. At the same time, the urbanization level is expressed as the city area proportion and six landscape metrics are chosed from density metrrcs, class area metrics, contagion metrics, diversity metrics and shape metrics in order to discuss the relationship between the urbanization level and the change of land cover landcape pattern. The regression analysis shows that there are significant correlations between the urbanization and six metrics.