Lake restoration from impoldering: impact of land conversion on riparian landscape in Honghu Lake area, Central Yangtze

Impoldering as a type of land conversion can impact both land cover and landscape characteristics. This study characterized the impact of identified lake restoration activities on land uses and riparian landscapes in Honghu Lake area in the Central Yangtze River, China using satellite remote sensing techniques. Landsat TM satellite images for 1987, 1993, and 1998 were classified and analyzed. The land covers were grouped into five types: water body, lacustrine vegetation, floodplain, cropland, and open land. By applying geographic information system (GIS), the spatial patterns of the land cover change over the 11year period were analyzed. Through overlaying three classification maps generated from the satellite imagery, the percentage of each of the land covers that were converted into other land use types was computed. Patch-related landscape indices were generated to analyze restoration impacts on landscape features. The study indicates that the lake restoration from impoldering greatly changed the land cover and land use types and modified riparian landscapes in a considerably short period of time. Lake and landscape development after the restoration presented clearly two distinct periods, the changing phase and the stabilizing phase. The analysis also suggests that the restoration could affect riparian land type conversion by inundation due to increased water coverage and by land adaptation for changing land uses.