Which outcome occurs when a levee's freeboard is insufficient during peak discharge?

💡 Explanation

Levee overtopping directly causes channel avulsion, because the insufficient height causes floodwaters to breach the levee and carve out an alternate, lower-energy path. This mechanism causes avulsion, thereby moving the river; therefore overtopping, rather than downcutting, causes avulsion.

• Which consequence results when glacial outwash carries substantial loess?
• Which feedback results from increased temperate forest bioturbation?
• Which flow regime results from increased geostrophic balance deviation?
• Which outcome results when subduction causes hydrothermal vent blockage?
• Which outcome accelerates isolated sea stack erosion when wave diffraction occurs?
• Which consequence results when storms breach a barrier island?