The Multivariant Trend Analysis and Risk Appraisal ofDebris Flow in Dongcheng Town of Helong City

There are 21 debris flow gullies of all scales in the Dongcheng Town, which threaten the local people’s life and security seriously. At present, the developing trend of the local debris flows is up to the coming rainfall character and loose mass on the ground surface. So based on the rainfall data during 1990~2003, with a nonlinear grey dynamic model method,a predict of the hydrodynamic condition and combined topographic, geological and hydrographic conditions is made. This district satisfies the conditions that cause debris flows developing and deterioratesing. On basis of the investigated datas, we have carrid the spot estimation of 21 debris flow gullies. From the result, the gullies such as Xingcheng Sidui, Dabapu river have such potential tend to deliver calamity that need preventation and cure on focus. The other lower risk degree gullies need to be kept from deterioration originally too. Eventually the goal of comprehensive preventation and cure can be reached.