Study On Spatial-temporal Evolution Of Urban Morphology Based On Remote Sensing Technology

Five Landsat time-series images for 1994a,1999a,2003a,2009a and 2013a of Fuzhou urban area,which is the capital of Fujian province,have been used to analyse the urban morphology changes characteristics and the key influencing factors of Fuzhou urban area from 1994a to 2013a with the assistance of remote sensing and GIS technology.The study was based on the urban expansion of Fuzhou urban area and used the index-based built-up index(IBI)to extract urban build-up land information from the five images.Combining with landscape pattern index and relevant index and overlay analysis and eight-quadrant analysis to get the date of urban land use changes and distribution for 1994a,1999a,2003a,2009a and 2013a.The results indicated that during the 20-year study period the built-up area of main urban region in Fuzhou has increased from 69.40 km2 in 1994 to 264.93 km2 in 2013a,a net increase of 3.8 times than before.The artificial landscape gradually increased by occupying cultivated land,vegetation and other natural landscape.So that city landscape dominance increased and fragmentation degree gradually decreased.The city morphology turned to be more regular,showing the characteristics of the concentrated spatial distribution.The study also reveals that the urban growth has been slow in the first 10 years and fast in the late 10 years;At the same time,the change of urban morphology has an obvious directivity in different period,evolving from WN-ES direction to the trend of the WS direction.Results of influencing factors analysis showed that physical environment was the most critical factor affecting the process of urban expansion and morphology changes,especially the elevation and slope and river distribution of study areas.Meanwhile the socio-economic factor plays a dominant role in urban morphology changes.Under the influence of government policy,especially the city planning,the previously-dispersed urban areas of Fuzhou are almost connected with each other from east to west.This study demonstrated that urban morphology changed significantly in the past 20 years from 1994 to 2013.