Which mechanism increases flood extent past a levee during a prolonged river flood?

💡 Explanation

When a river flood lasts days, capillary action saturates the levee because water wicks through pore spaces, decreasing soil stability and increasing seepage, extending the inundation zone beyond initial points of failure. Therefore capillary action results in increased flood plains, rather than stabilization, permeability reduction or impeding existing downstream sediment transport processes.

• Which outcome occurs when trade winds approach mountainous islands?
• Which erosional outcome occurs where strike-slip motion terminates along transform boundaries between oceanic plates?
• Which geographic outcome occurs when an oceanic plate subducts under a less dense continental plate?
• Which mechanism causes tsunami formation during a subduction zone earthquake with significant vertical displacement?
• Which outcome occurs when a subducting slab dehydrates at intermediate depths (~100 km)?
• Which outcome results when transform fault motion is impeded?