Distribution of Landslides in Baoshan City,Yunnan Province,China

Using Google Earth software as a platform,this study has established an integrated database of both old and new landslides in Baoshan City,Yunnan Province,China,and analyzed their development characteristics together with distribution rules,respectively.Based on the results,a total of 2 427 landslides occurred in the study area,including 2 144 new landslides and 283 old landslides,with a total area of about104.8 km2.The new landslides are mostly in small-scales with an area less than 10 000 m2,while the area of individual old landslide is mostly larger than 10 000 m2.By analyzing the relationship between the two types of landslides and eight impact factors(i.e.,elevation,slope angle,slope aspect,slope position,lithology,fault,regional Peak Ground Acceleration(PGA),and average annual rainfall),the different individual influencing factors,distribution regularities and mechanisms of the two types of landslides are revealed.In detail,the main influencing factors of new landslides are elevation,slope angle,slope aspect,slope position,lithology,regional PGA and average annual rainfall,while the influencing factors of old landslides are mainly elevation,slope angle,and lithology.This study provides basic data and support for landslide assessment and further disaster reduction in Baoshan City.Besides,it also provides new constraints in deeply understanding the effect of different topographic and geological conditions,historical earthquakes,rainfall and other factors on the occurrence mechanisms of both new landslides and old landslides.