Protecting Floodplains by Aaron Dante Mamiit
Flooding is a constant issue faced by Metro Manila. Although there are times when flooding is merely an inconvenient and annoying event, there are also times when it develops into something much more frightening and dangerous.
But why is Metro Manila so badly plagued by floods anyway?
One of the reasons why Metro Manila constantly battles with the flood problem is because a large part of it is situated on a floodplain.
What are floodplains?
Floodplains are landscapes that are formed when running water, often in streams and rivers, transports eroded rock and other similar materials from their banks to a lower part of the Earth’s surface. At these lower parts, the flow of water slows down, and the rock and materials that the water is carrying are dropped.
This leads to the creation of deposital landforms. One of these landforms is the floodplain.
Floodplains are nearly flat, hence the “plains” part of their name. The “flood” part, on the other hand, should be pretty obvious – these floodplains are subject to periodic flooding.
What happens on floodplains?
Flooding occurs when water overflows from a stream or river. When the water levels become too high, the water flows out of the stream channel and over the stream banks, submerging the adjacent floodplain.
As water overflows, the material it carries – sediments such as sand, gravel, clay, and silt – are deposited on the floodplain.
The larger particles are deposited first, closer