Analysis of Debris Flow Source in Jiajungou Watershed before and after Heavy Rainfall after Sichuan Province"9.5"Luding Earthquake
On September 5,2022,a 6.8 magnitude earthquake occurred in Moxi Town,Luding.The strong earthquake greatly increased the source of loose solid matter in the region.On the evening of June 26,2023,the Jiajungou Valley experienced short-term concentrated heavy rainfall,and the debris flow disaster broke out,which seriously threatened the life and property safety of the villagers in debris flow exit.In this paper,by means of high-resolution remote sensing image data and field investigation,the distribution characteristics and change rules of provenance in Jiajungou Basin before earthquake,after earthquake and after earthquake rainstorm,as well as the influence of earthquake and rainfall on debris flow provenance are analyzed.The results show that the total amount of provenance in Jiajun Valley area increases 1.9 times after earthquake and 12.1 times after rainstorm compared with before earthquake.The total amount of source in Banchanggou area increased 1.2 times after the earthquake and 2.1 times after the rainstorm compared with before the earthquake.The source quantity of debris flow after earthquake has great concealment and lag.It is feasible to estimate the solid source of debris flow based on remote sensing interpretation in earthquake area.This study can provide a reference for estimating the net reserves of similar debris flow after the earthquake and engineering treatment.
Source characteristics of debris flow"9.5"Luding earthquakeHeavy rainfallRemote sensing imageConcealmentHysteresis
NETL
NSTL
万方数据
