Main geohazard types in Longling segment of the Dali-Ruili railway, western Yunnan and their development characteristics

Longling area along the Dali-Ruili railway is located in western Yunnan canyon area of Yunnan Plateau, in the watershed zone between the Nujiang River and the Irrawaddy River drainages, where new tectonic movement is intense and seismic activity occurs frequently. The rainfall in this area is focus on May~October, and the rainfall intensity is large and concentrated. Because of the complicated geological environment, with the addition of rainfall, human activities and other exterior factors, geohazards such as collapses, landslides and debris flow have repeatedly occurred in this area, which often cause accidents such as washing out paddy fields and forests, destroying highways, bridges and buildings, and personnel casualties. The authors analyzed the distribution, formation conditions and development regularity of main geohazards in this area. The result obtained provides a geological basis for the planning and construction of the Dali-Ruili railway and social economic development of the surveyed zone.