Farmland Landscape Pattern Change in Changping District of Beijing in Recent Ten Years

With the development of economy in recent years, Beijing's urbanization is rapid expansion and it has great influence on suburban farmland. This article analyzed the variation of the cultivated land and landscape pattern during the period of 1998-2009, based on TM images data in 1998 and 2009, land use map and administration planning map of Beijing in 2005, by the RS, GIS and Fragstas software platform. The results showed as follows: That the cultivated land in Changping District of Beijing had converted mainly into construction land about 10818.36 ha with the percentage of 48.45, but also forest land converted into cultivated land about 7740.99 ha. The indexes of landscape pattern had different change trend. The CA decreased about 13.8%, however, NP and Pd increased 75.7%, which meant that the fragmentation degree of landscape had increased; the AI and CONTAG of mosaic indexes had decreased 5.9% and 11.9%, and also the same declined trend for the PLAND and LPI of dominance indexes with 13.8%, 72.7% respectively, but the increased 16.2% for the Shannon diversity index, which meant that the heterogeneity intensity of landscape had increased, and connectivity decreased; the LSI and ED had the same increased trend of 36.1% and 26.3% respectively in the past 10 years, which meant that the boundary of patches had more complex characteristic.