Abstract:With a shallow epicenter and extraordinary intensity,numerous secondary mountain hazards,including landslides and debris-flows,were triggered by the "8·30" earthquake occurred at Huili County,Sichuan Province.Nuozha gully,one of the tributary of Jinsha River,located in the southernmost of Huili County.The gully experienced a large number of rock-falls,landslides and collapsed slopes induced by the earthquake,which offered sufficient loose materials for the debris-flow.Furthermore,the right branch of the gully has a very large catchment area,which provides the energy and water source for possible outburst of debris-flow.Based on historic documents and field scouting,the downward and headwater erosion of Nuozha Gully,enhanced by downward erosion of Jinsha River,were the leading factors for reduced slope front resistance,resulting in unstable slopes and increasing failures in the upstream.The risks and trends of geohazards were assessed for the gully.Geotechnical engineering,including check dams,debris dam,as well as ecological measures like forest planting,were recommended for controlling debris-flow of Nuozha gully.