Landslide Hazards along River Corridors - Lowland fans

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.沉积扇（depositional fan）形成于沿陡坡河道运移的沉积物在河道坡度骤降处堆积的场景，例如陡峭谷壁支流汇入谷底之时。此类陡坡河道中的沉积物可通过流态型滑坡（包括碎屑流、碎屑洪水）运移，亦可由地表径流携带。依据上述活跃过程的类型，沉积扇会面临一系列不同的灾害风险。