Prediction On The Hazard Extent Of Volcanic Secondary Debris Flow With LAHARZ

As a kind of disasters induced by volcanic eruption, Volcano Secondary DebrisFlow can destroy towns, engulf engineering facilities, buried farmland, and evencause a large number of casualties, it’s one of the most important volcano secondarydisasters. Volcano Secondary Debris Flow is mainly the mixture of the volcanicmatters and water with high velocity, high density, large volume of fluid, and alwaysflow along the valley lowlands, will cause serious of consequences, therefore, toforecast the extent of Volcano Secondary Debris Flow has important engineeringsignificance and social realistic sense.Changbai Mountain is located in the border area of Southeast China’s JilinProvince and the northeast border with North Korea, as china’s famous nature reservesand scenic tourist resort. The top is a volcano Lake-Changbai Mountain lake formedby volcanic eruption. It’s circumference is about13km, the catchment area of9.82km2, the average water depth is about200m, the depths of373m, the water capacityof2040000000cubic meters. Volcano eruption, once again, will cause the lakeoutburst, and trigger a secondary volcanic disaster-Volcano Secondary Debris Flow.This paper combining with the practical investigation and the indoor simulation test,take the application of LAHARZ software to predict the extent of Changbai MountainVolcano Secondary Debris Flow. The main conclusions are summarized as follows.1Analysis on the influence factors in study area, the factors such as meteorology,hydrology, formation lithology, topography, geomorphology and hydrologic geology,thus to provide reference for analysis on the trajectory of Volcano Secondary DebrisFlow extent.2According to the field investigation and indoor experimental data, analysis ofthe main types of the volcano clastic material and distribution in study area, obtain theinfluence factors about Volcano Secondary Debris Flow: loose solid debris,meteorology, hydrology, topography, water etc. 3Select the following parameters collected with the actual investigation and data:setting365as the minimum height threshold, determining the optimal threshold forthe5000, river energy cone with an average slope of3.58degrees, the study areaenergy cone threshold is0.07.4By setting different gradient (108,109,1010,1011,1012) of the total volume ofvolcano secondary debris flow threshold, LAHARZ software is used to simulate thedistribution of different gradient value extent with5levels.5Through the extent of Volcano Secondary Debris Flow in study area, discussedthe main disaster-causing boundary and harmfulness.