GEOLOGY
GEOMORPHOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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As they travel further downwards, the meanders becomes narrower
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May migrate sideways leading to the formation of floodplains
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As they migrate downwards, they may eventually turn into waterfalls/gorges
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Meanders migrate downstream and erode river cliffs (outer bank)
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Detailed explanation-1: -Meanders change position by eroding sideways and slightly downstream. The sideways movement occurs because the maximum velocity of the stream shifts toward the outside of the bend, causing erosion of the outer bank.
Detailed explanation-2: -Water is pushed to the outside of a bend, and erodes the curve further, while water on the inside is slower and deposits sediment. This is why you often see sand bars and beaches on the inside of the curve. Due to erosion on the outside of a bend and deposition on the inside, the shape of a meander changes over time.
Detailed explanation-3: -As the surface flow of water hits the outer bank it corkscrews, flows along the river bed then deposits eroded material on the inner bank. Erosion is greatest beyond the middle of the bend in the meander. This causes the meander to migrate downstream over time.
Detailed explanation-4: -Meander bends migrate in a downstream direction, and river channels can move laterally across the valley floor over time. This migration occurs as the outsides of the bends erode and gravel bars are deposited on the inside of the bend.
Detailed explanation-5: -Meanders, named from the Menderes (historically known as the Maeander) River in Turkey, are most often formed in alluvial materials (stream-deposited sediments) and thus freely adjust their shapes and shift downstream according to the slope of the alluvial valley.