Aerial view of the Amazon River
A new research points out that rivers with various channels have margins with a faster erosion pace that the sediment deposit cannot collect.
A new published in Science has finally unveiled a centenary mystery: Why do some rivers divide into various channels, while others flow like a single watercourse? The answer lies in the balance between the erosion and the deposition of sediments, According to researchers at the University of California.
The team analyzed 36 years of 84 river satellite data from around the world. Their findings show that rivers develop multiple channels when their margins suffer erosion faster than the sediments are deposited on the opposite side. This imbalance causes the river to widen until it divided naturally, explains the.
This conclusion challenges ancient premises in the field of geomorphology. While previous research was based on small -scale models or focused mainly on Single flow riversLike Mississippi, this study used satellite images and velocimetry of particle images to track erosion and deposition in real rivers on a global scale.
Rivers with a single course maintain a balance between erosion and deposition, allowing them remain narrow and serpent. In contrast, multiple course systems continually reshape as erosion exceeds deposition, forming islands and bars that divide the flow.
Interestingly, the volume of water is not the main factor, but rather the way this water interacts with sediments and margins. Most river sediments with various courses ends up in bed, not on the banks, favoring divisions. A remarkable atypical case was the São Francisco River, in Brazil, which deviated from the standard Due to dams and the amount to the amount.
The implications for the risk of flooding and environmental restoration are significant. In the past, many rivers were forced to follow a single channel To accommodate development, which isolated them from their natural flood plains. This increased the risk of flooding and affected ecosystems.
The research team has developed a formula to help planners determine how much space and time are necessary to restore rivers to their natural states. The rivers with a single course require up to 10 times more space and time To recover than rivers with various courses, a discovery that can make restoration projects more viable and economic.
