Classification of"7 24"Rainstorm Debris Flow Based on Start-up Model in Luanchuan County of Henan,China

In July 2010,there had being continuous raining for half month in Luanchuan County of Henan province,China.Yet heavy rain was falling on 24th,which resulted a regional debris flow happened.The whole 14 towns of Luanchuan County suffer loss that left 68 people dead,21 people missing and caused a total direct economic loss of 19.8 billion yuan(RMB).In order to give some reasonable suggestions to local government for debris flow prevention and treatment,methods of field investigation and engineering geological analysis were took to study the 31 disaster points of this regional debris flow event.The investigation found there are abundant debris types in this event,such as mudflow,debris flow and water-rock flow.In topography classification,debris flows are often slope type,but water-rock flows are almost gully type.Yet mining industry developed in Luanchuan county,so mine waste debris flow developed and typical and most of them broke out since tailings dam busted.Codes classification can’ t give specific suggestions to debris prevention and treatment as Luanchuan county debris broke in large area and types were rich,but start-up mode classification can.So based on previous research and project investigation analysis,these debris flow points were divided into seven types based on start-up model.They are dragging and busting joint action model,punching and slumping joint action model,impacting induced liquefying model,slope slumping model,slope washing and gully start-up joint action model,tailings busting model and combinational model,respectively.Moreover,detailed analysis of seven typical debris points,which belongs to the seven debris types,was conducted.