When a flood erodes the sides of river where do materials go?

Materials eroded from the sides of a river during a flood are transported downstream and deposited in various locations. Here are the main depositional environments:

1. Floodplains: As floodwaters overtop the river banks and spread across the adjacent land, they lose velocity and begin to deposit their suspended sediments. These sediments accumulate on the floodplain, building up its elevation. Over time, floodplains can become fertile agricultural areas due to the periodic deposition of nutrient-rich sediments.

2. Point Bars: On the inside bends of meandering rivers, where the water velocity is slower, sediment deposition occurs. Point bars are formed by the accumulation of sand and gravel as the river flows around the bend. These deposits can eventually emerge as islands or become attached to the river bank.

3. Mid-Channel Bars: Mid-channel bars are sediment deposits that form in the middle of a river channel. They are commonly composed of sand and gravel and are often associated with changes in river flow patterns, such as the merging of two channels or the presence of obstructions.

4. Levees: Levees are natural embankments that form along the banks of rivers. They are composed of fine sediments, such as silt and clay, which are deposited when floodwaters overtop the river banks and lose velocity. Levees can help protect adjacent areas from flooding, but they can also increase the risk of flooding downstream if they fail.

5. Delta: When a river reaches a large body of water, such as a lake or the ocean, its velocity decreases significantly. This causes the river to deposit its sediments, forming a delta. Deltas are typically composed of layers of sand, silt, and clay, and they can extend for many kilometers into the body of water.

The specific locations where eroded materials are deposited during a flood depend on factors such as the river's flow velocity, sediment load, and topography of the surrounding area.