Effect of Wenchuan Earthquake on Soil Physical and Chemical Properties of the Longmen Mountain, Southwestern China

The Ms 8.0 Wenchuan earthquake in 2008 led to huge damage to land covers in northwestern Sichuan,one of the critical fragile eco-regions in China.In this paper,the soil physical and chemical properties at the landslide sites induced by the earthquake were assessed in a comparable framework which included three regions,i.e.eastern side,western side and the transitional zone of the Longmen Mountain,and represented different climate and vegetation background.Compared with the undisturbed area,the results indicated that soil sand content increased significantly on the landslide of all case-study areas(P0.05),while cation exchange capacity,organic matter,total nitrogen,total phosphorus,nitrate nitrogen,mineral nitrogen,silt content and clay contents decreased significantly(P0.05) in all three research regions.The soil pH,the ammonia nitrogen content,and the ratios of mineral nitrogen/total nitrogen and C/N did not show a regular trend.Moreover,the total potassium content did not change obviously(P0.05) in the three regions.In conclusion,most of the soil quality indices decreased significantly on earthquake-triggered landslides.