Formation and Characteristics of Gully-type Debris Flow on Hilly Plateau Planes with Cold Climate and High Altitude of Sichuan Proince -A Case Study of the Zhusang Scenic Spot in Yajiang County of Sichuan Province
There are some differences between the debris flows formed in valley areas and those formed onhilly plateau planes.The formation and characteristics of debris flows in the Zhusang scenic spot in YajiangCounty of Sichuan Proince were studied by field investigation,on-the-spot survey and sieving test.Resultsindicate that:(1)The special climate with intensive sunlight and large difference in temperature plays animportant role in the formation of gully-type debris flows on the hilly plateau planes by making physicalweathering processes intensive,solid deposits loose,slope stability low and supplied materials abundant.(2)Landslide and gully-bed erosion consist of two main material-supplying ways.(3)The dynamic conditions of debris flow are relatively weak.(4)In terms of drainage characteristics,the longitudinal curve takeson a poly-line configuration and the conflux zone and formation zone can be divided obviously.(5)Comparedwith the debris flows in the valley areas,the debris flow deposits on hilly plateau planes are more uniform ingrain size.