Not many people understood why about this phenomena which keep some people scratching their head when a sudden flood occurred during a sunny day. It happened during the great earthquake which affect areas around Ranau and Kota Belud as well as triggered the largest and devastating outcome after Greg Storm passed through Keningau. Landslide and quake dam is the outcome of built up which creates natural dam from natural flocculation and sediment load due to various erosion (both banks and surface) and transportation types. The increasing height of debris and sediment create artificial wall(s) which retain and contain water until the point where the hydraulic pressure is greater than the wall (cohesion or friction angle or even combined) and thus cause the wall to breach and lead to overflow. This sudden overflow and the magnitude of the flow depend on the type of breach or failure at the upstream and the downstream is at the mercy of the river capacity and amplification due to topography. Only spatial distribution and luck will give you a lucky escape. If you live around such area, you are one Hail Mary prayer away from being safe due to evaporation and possible infiltration. Else, with impermeable clay - you can start with John 3:16.
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