The river has a high possibility of corrosion due to the very stony soil formation.

A deforestation is a big problem at nowadays, every day many company cut trees everywhere without plant others.
We need to do something or one day we don't have any forest left.

Deforestation caused by human activity in the woods.  It is dangerous because without any trees the land is tends to collapse. Deforestation is a big problem for everyone:animals, nature and man.
And the rain is not slowed down by the trees and gets faster to the rivers, causing overflow. 

 

A floodplain consists of two parts. The first is the main channel of the river itself, called the floodway. Floodways can sometimes be seasonal, meaning the channel is dry for part of the year. The floodway of the Todd River in Australia’s Northern Territory, for instance, is an ephemeral stream, meaning its channel can be dry for months at a time.

 

Beyond the floodway is the flood fringe. The flood fringe extends from the outer banks of the floodway to the bluff lines of a river valley. Bluff lines, also called valley walls, mark the area where the valley floor begins to rise into bluffs. The flood fringe of the seasonal Todd River extends the floodplain to 445 square kilometers (170 square miles). 

 

Some floodplains are extraordinarily wide. The Barotse floodplain of the Zambezi River, for example, is a vast wetland stretching thousands of kilometers through Angola, Zambia, and Botswana. The Barotse floodplain includes the sandy Kalahari basin, which is waterlogged during the rainy season and an extension of the nearby Kalahari Desert during the dry season.

 

Some rivers have very narrow floodplains. In fact, some rivers, or parts of rivers, seem to have no floodplain at all. These rivers usually have a steep stream gradient—a very deep, fast-moving channel. Ngonye Falls, Zambia, marks a remote stretch of the Zambezi River where the floodplain is extremely narrow. As the Zambezi leaves the wide floodplain of the sandy Kalahari, it enters a narrow basalt channel as fast-moving whitewater rapids.

 

 

There are two major processes involved in the natural development of floodplains: erosion and aggradation. The erosion of a floodplain describes the process in which earth is worn away by the movement of a floodway. Aggradation (or alluviation) of a floodplain describes the process in which earthen material increases as the floodway deposits sediment.

 

A river erodes a floodplain as it meanders, or curves from side to side. The massive lowland floodplain of the Amazon River, for instance, is carved with hundreds of oxbow lakes that document the meandering river and its tributaries over time. Oxbow lakes are formed when a meander, or bend, in the river is cut off from the river’s mainstem. Features such as oxbow lakes and seasonal wetlands are often a part of floodplains created through erosion and deposition.

 

A meandering stream can contribute to a floodplain’s aggradation, or build-up in land elevation, as well as its erosion. A typical aggradation environment is a wide, shallow, braided river. Braided rivers often include river deltas, where the main floodway is separated into discrete channels and tiny islands. The process of subsidence, in which the elevation of a delta may sink due to sea level rise or human activity, often offsets aggradation in the floodplains in these areas. The huge aggradation of sediment around the Nile delta, for instance, is subsiding due to the rising level of the Mediterranean Sea.

 

The alluvium, or sediment, of a floodplain varies. Its coarseness and composition depend on the surrounding landscape and the velocity of the currents that created the floodplain. Some floodplains are mostly fine-grained silt, while others are sandy. 

 

The deposit of alluvium created as a river or stream breaks, or breaches, its bank is called a crevasse splay. The formation of a crevasse splay is very similar to the formation of an alluvial fan. The thickest layer of sediment is nearest the breach, while the thinnest and youngest sediments are fanned out.

 

The layered sediments of many floodplains can create important aquifers. Clay, sand, and gravel filter water as it seeps downward. Water purification systems often take advantage of this natural phenomenon in a process called bank filtration. In bank filtration, water is deliberately filtered through the banks or floodplain of a river or lake. Nearby wells then collect the filtered water, which is then ready for more intense purification processes.