Monitoring urban encroachment on cultivated land with TM images in China

After the implementation of ´Reform and Open policy´, the double-pressure of rapid economic development and population growth has imposed an unprecedented profound impact on Chinese dynamic change of land-use patterns (Tian 1999, Shi 2000, Liu 2000). One of the most important problems is urbanization and cultivated land protection (Ji, Liu, Sun 2001). With only 0.106 hm² arable land per capita, China has only 44.9% of the world average arable land. Rapid urbanization and industrialization have resulted in a sharp reduction in arable land acreage. The appearance of ´Development Zone´ and ´Real Estate´ hotspots pattern a great amount of land and capital, which results in the serious social and ecological problems. With the rapid, high technological, neo-information and dynamic characteristics (Liu 1997), remote sensing has been applied in land use and environmental monitoring widely. The paper studies urban encroachment on cultivated by TM images and puts forward the measures to control cultivated land loss.