Temporal-Spatial Processes of Farmland Conversion and Its Driving Mechanisms in Beijing
北京耕地流失的时空特征与驱动机制

Non-agricultural use of farmland and the problems associated have been thematic issues worldwide.China is also facing many land use problems brought by fast economic growth,urbanization and industrialization with fast farmland losing as prices.Taking Beijing as a case,the temporal-spatial processes of farmland conversion and its driving mechanisms were discussed in this paper.Based on the land-use dataset in 1996 and 2001,digital topography and transportation maps and social-economic statistic data from 1986 to 2004,the land use change information in Beijing was extracted.The effects of human activities on farmland change process were explored by GIS and the driving forces of cultivated land change were investigated.It is found that : 1)Farmland loss is the main character of land use in Beijing from 1996 to 2004,the conversions of all land use kinds are related to farmland change;among various factors threatening the sustainability of farmland,the most outstanding and the most serious one was the occupation on farmland for building and industry development because of urban expansion;the farmland loss is mostly those high quality land in the plain area;2)The topography and transportation situations show the obvious effect on the farmland distribution;most farmland distributes and changes in the plain area of low elevation;the cultivated land-use intensity decreased obviously with the increase of distance from the main communication arteries;3)The rapid development of tertiary-industry is the main driving force of farmland loss in Beijing,which helped more and more people obtain employment and activated more and more demands of real estate;the correlation coefficient between the tertiary-industry production and the per capita income of staff and workers is 0.994,which can well explain the farmland change of Beijing from 1986 to 2004;farmland loss is also driven by rapid population increase,regional land market malignant competition, the structural adjustment of agricultural land and ecological construction policy.