Abstract:Kongpo Gyamda is located in eastern Tibet, where debris flows occur frequently in the rainy season, which has a serious impact on local people's daily life and hinders regional economic construction and development. In order to study the hazard characteristics of small to medium-sized debris flow in eastern Tibet and potential dangers to urban residential areas, the FLO-2D software was used to study five debris flow gullies with relatively concentrated residents around Kongpo Gyamda. The scouring and silting characteristics of debris flows were simulated. Based on the simulation results in terms of depth and velocity, the intensity and hazard zoning of debris flows were determined. By analyzing the topological relationship between the debris flow danger zone and the residential area, the debris flow risk around the county was evaluated. It provides technical reference for the town planning, and disaster prevention and mitigation in Kongpo Gyamda.