Variation in soil erosion based on USLE model and remote sensing technology during 2000-2010 in Gansu Province

Combined USLE (Universal Soil Loss Equation) with remote sensing, geographic information technologies, the distribution area of soil erosion was evaluated quantificationally in Gansu Province from 2000 to 2010. The results showed that the mainly erosion intensity was mild and moderate erosion in Gansu Province.The soil area with significant erosion was 24 872.9, 27 503.6 and 28 000.8 km2 in 2000, 2005 and 2010, respectively. The region of soil erosion mainly distributed in the southern part of Gansu Province, and the main soil erosion area distribute in forest and grassland. The largest soil erosion area distribute in forest,followed by grassland. The main landforms types of erosion are mountain land in Longnan, Gannan and loess plateau. The variation in soil erosion from 2000 to 2010 was also analyzed, it indicated that the reasons of soil erosion were not only by uneven distribution of precipitation, land-use types and landform types, but also irrational useage of ecological environment.