Land use changes in a reddish soil erosion region of Southern China: Hetian Basin, County Changting

County Changting in Fujian province was one of the most severe reddish soil erosion regions in South China. After more than 20-year efforts, County Changting has achieved a great success in the treatment of the soil loss and thus become a model in China in this regard. Therefore, the study on the land-use dynamics responding to the county's soil-loss treatment is particularly meaningful. This study used remote sensing technology to analyze land use and landscape dynamics in the Hetian basinal area for a long period from 1988 to 2011 because this area is the most serious soil erosion area in the county. Five remote sensing images were used in the study, which represent the years of 1988, 1998, 2004, 2009, and 2011, respectively. The latter three images are SPOT 5 10m resolution multispectral images, while the 1988 and 1998 images are Landsat TM 30m resolution multispectral images. To keep consistent in the spatial resolution with SPOT 5 images, therefore, the 30m TM images were fused with near-date-coincident 10m SPOT Pan images, respectively, to achieve a 30m resolution. The supervised maximum likelihood classification and change detection technique were used to reveal the land use dynamics. In addition, the spatial pattern analysis was carried out to study accompanied landscape pattern variations. The results show that the land use in the Hetian basinal area has greatly changed during the 23 study years. The forest land and built-up land have increased rapidly, while the bare soil land dropped considerably. Spatial pattern analysis indicates that while decreased, the bare soil has also been fragmentized since 1988. This suggests that the local eco-environment has been substantial improved during the study period.