“5·12”汶川大地震后无林地土壤物理性质的变化

Physical Properties Change of Non-forest Soils after 5·12 Wenchuan Earthquake

2008年5月12日，四川省汶川县发生Ms8．0、裂度1l级的灾难性特大地震，造成了严重的人员伤亡，同时也对森林生态系统造成了严重伤害。在主地震带上的四川省绵阳市，以无林地上未滑坡、滑坡和崩塌3种立地类型的土壤为研究对象，于2009和2010年分别研究了地震后各立地类型不同层次的土壤容重、毛管持水量、毛管孔隙度和非毛管孔隙度。结果如下：（1）大地震后无林地土壤物理性质受影响程度为崩塌〉滑坡〉未滑坡；（2）经过1a的自然恢复，各立地类型的土壤容重没有恢复；未滑坡样地和滑坡样地土壤表层（0～10cm）的毛管持水量、毛管孔隙度和非毛管孔隙度得到有效的恢复，土壤中层（10～20cm）和深层（20～40cm）的相应指标虽有相同的变化趋势，但变化并不显著；而崩塌样地由于土壤结构被严重破坏，恢复缓慢。

A catastrophic devastating earthquake that measured at Ms 8.0 and the degree of crack 11 occurred on May 12, 2008 in Wenchuan of Sichuan province. It caused thousands of people death and serious harm to forest ecosystems. The physical properties of different depths soil in different site （unmoved, landslide and col- lapse areas） of non-forest were studied in 2009 and 2010, in Mianyang which located in the fault belt. The indexes included soil bulk density, capillary moisture capacity, capillary porosity and non-capillary porosity. The results were as follows： The influence degree of earthquake was the collapse 〉 landslide 〉 non-moved area of non-forest land. After a year, the bulk density have had not recovered, the capillary moisture capacity, capillary porosity and non-capillary porosity of 0--10 cm depth soil in the non-collapse and landslide site have had effectively improved; 10--20 cm and 20---40 cm depth soil had the same trend, but the change was not significant. The soil structure of collapse site has been serious damaged and recovered slowly.