Discuss the formation of levees by referring to FIGURES 2 and 3.

1.5.1 What is a levee? A levee is a natural embankment of sediment that builds up along the banks of a river. A natural embankment formed by deposition of sediments on the river banks during floods. 1.5.2 Levees are mainly constructed where? Levees are mainly constructed on the banks of a river. on the banks 1.5.3 State the process responsible for the formation of levees. During floods, rivers carry large amounts of water and sediments. When the water overflows the banks, its velocity decreases and sediments (especially coarser ones) are deposited near the river channel, building up the banks into natural levees. Finer sediments are deposited farther away, forming the floodplain. Deposition of sediments on river banks when floodwater velocity decreases after overflowing. 1.5.4 Discuss the role of levees in flood prevention. Give two advantages and two disadvantages. Levees (especially artificial ones built on natural levees) aim to contain river water during floods and prevent flooding of adjacent areas. Two advantages: 1. Protects farmland and settlements on floodplains from flood damage, allowing safe farming activities. 2. Increases the river's channel capacity by raising bank height, reducing flood risk for higher flows. Two disadvantages: 1. If overtopped or breached during extreme floods, water held back causes more severe flooding behind the levee. 2. Prevents natural sediment deposition on floodplains, leading to loss of soil fertility over time for farming. Advantages: 1. Protects farms/settlements. 2. Contains higher floods. Disadvantages: 1. Breaching worsens floods. 2. Reduces floodplain fertility.