Remote Sensing Monitor and Spatial-temporal Process' Analyses on Urban Expansion of Changchun City During Past 50 Years

The urban spatial expansionis the exhibition of the urbanizationphenomenon in space.Therefore the urban spatial expansionis one of the importantmeasure indexesto estimate the level of the urbanization.Because China is in the rapid developmentperiod of urbanization,toknowthe information of urban expansion in time has important value to urban planning,urban construction,urban management and decision-making.The thesis combined topography map and remote sensing data to analyze and research the spatial-temporal process and mechanism of the urbanexpansionin Changchun city during past 50 years.During past 50 years,the urban expansion was quick in Changchun city,as a whole,having been well ordered,mezzo speed and continuableprocess.When new polycentricand group urban expansion are occurring,to effectively carry out new master urban planning and protect basiccropland are urgent affairs.