Estimating gully development rates in Hilly Loess Region of Western Shanxi province based on QuickBird images

Gully erosion is a significant source of damaging land resources and river sediment. In order to explore the effectiveness of high-resolution remote sensing images in monitoring the development of gully, four small watersheds on the eastern hilly loess plateau were selected to compare changes of the area and circumference of the gully region and the headcut development rate of gully from 2003 to 2010, based on high-resolution remote sensing data (QuickBird images) and GIS. Factors controlling gully development were analyzed including vegetation cover and land-use. The results showed that the increasing rate of area within the gully region ranged from 0.25% to 0.48% in four small watersheds, and the change of circumference was between 1.56% and 2.61% .Gully expanded mainly on side branches with the rate of 0.36-0.44 m/a. Vegetation coverage larger than 60% on the drainage area could evidently inhibit the development of a gully. The change of gully area, circumferences and gully headcut development rates were all smaller in watersheds with more forest coverage. This study suggested that high resolution remote sensing can be used to derive gully headcut development rate quickly and accurately at middle spatial and time scales.