Landslide Hazards along River Corridors - Alpine fans more likely subject to debris flows

For more information about this layer please see the GIS Data Catalog. Depositional fans are formed when sediment moving down a steep channel is deposited where the channel gradient abruptly decreases, for example where a steep valley-wall tributary reaches the valley floor. Sediment can be carried down such a steep channel in flow-type landslides (debris flows, debris floods) or as sediment can be carried by streamflow. Fans are subject to a range of hazards depending which of the preceding processes are active. Debris flows are a style of landslide movement that entail landslide debris moving in a fluid state down a channel, often travelling a long distance from the point of origin. This layer represents fans that are located in alpine areas and are more likely subject to debris flows.如需了解该图层的更多信息，请参阅地理信息系统（GIS）数据目录。当沿陡峭河道搬运的沉积物在河道坡度骤然变缓的区域（例如陡峭谷壁支流汇入谷底之处）沉积时，便会形成沉积扇。此类陡峭河道中的沉积物可通过流动型滑坡（碎屑流（debris flows）、碎屑洪流（debris floods））输送，亦可经由地表径流携带。根据上述活跃过程的类型，沉积扇会面临多种不同的灾害风险。碎屑流是一类滑坡运动形式，指滑坡碎屑以流体状态沿河道移动，通常可从起源点长途运移。本图层所表征的是分布于高山地区、更易受碎屑流影响的沉积扇。