Hydrosphere: River Erosion Processes

Question 1

Hydraulic action

Answer 1

• the sheer force or the water hitting the banks can cause air to compress in cracks
• this weakens the banks, breaking off chunks of soil and rock
• in time, may cause riverbanks to collapse

Question 2

Abrasion

Answer 2

• the sandpaper effect of rocks and debris in the river hitting the banks, scraping and scouring them away
• assists in vertical erosion

Question 3

attrition

Answer 3

• rocks carried by the river hitting against each other, breaking into smaller parts
• causes rocks to become rounded and smooth
• does not erode the bed or banks

Question 4

solution

Answer 4

• when weak acids in the river dissolve minerals in rocks
• this weakens them, causing them to break apart or become more vulnerable to other erosional processes