Analysis on the Spatial-temporal Changes of Cultivated Land and Their Driving Forces in Zhuhai

This paper aims at revealing how cultivated land changed since the 1990s in Zhuhai.Based on the Aremote sensing data of 1990,1995,2000 and 2006,combined with social-economical statistic data from 1990 to 2006,spatial and temporal changes and mutual conversion with other land use of cultivated land in the past 16 years are analyzed quantitatively by means of GIS technology.Furthermore,the driving forces of cultivated land change are discussed in details by the method of principle component analysis.The results show that the area of cultivated land has undergone a process of rapid decrease-slow increase-dramatical decrease,with a total decrease of 33 585.38 hm2 in the whole periods and an average of 2 099.09 hm2 per year.It was spatially distributed in Doumen region and Xiangzhou region,per capita cultivated land reduced continually from 0.105hm2 in 1990 to 0.023 hm2 in 2006.The dynamic degree of cultivated land use was the biggest from 2000 to 2006.In addition,the dynamic degree of paddy field was bigger than that of cultivated land and dry land in three study periods,which indicated that the change degree of paddy field was the fiercest in cultivated land types.By mutual conversion analysis of cultivated land and other land use,it is found that the increase of cultivated land area mainly originated from water body(56.75﹪) and woodland(31.32﹪),The lost area of cultivated land were 50 840.43hm2,which were mainly converted to water body(50.84﹪)and construction land(33.88﹪)in the past 16 years.Development in economic and population and adjustment of agricultural structure are shown to be the dominating driving forces for the cultivated land change in the whole study period.Simultaneously,government policies play an important guidance role.