Dynamics and Driving Factors of Agricultural Landscape in Jianghan Plain

Abstract

The land use structure changes during 2000-2005 in agricultural landscape in Jianghan Plain are described, using following indices: landscape percentage (%LAND), patch density (PD), mean patch size (MPS), total edge length (TE), mean shape index (MSI) and landscape shape index (LSI). The spatial land use data was from land use database of CAS. Through interpreting Landsat TM images of 2000 and 2005 respectively, the land use change data was extracted to describe the overall agricultural landscape structure changes during 2000-2005 by spatial analysis with Supermap platform. The results show that arable land, woodland and unused land have decreased while the grassland, water areas and construction land have increased. The noticeable changes are the decreased arable land and the increase in lakes, reservoirs and ponds. Amongst the landscape indices are the increases in MPS and MSI and the decreases in PD, TE and LSI. The indices suggest that the agricultural landscape in the study area becomes less fragmental and heterogeneous resulting from intensification of agriculture and agricultural mechanization. The study shows that the changes in the agricultural landscape pattern are caused not only by urbanization but also by the governmental policies, such as the conversion of farmland to lakes, agricultural restructuring and land development and arrangement.