Which risk increases when rapid urbanization constricts a river channel with natural levees?

💡 Explanation

When urbanization constricts a river channel with natural levees, less floodplain area and increased impervious surfaces reduces infiltration and increases runoff. Consequently, flash flooding risk increases due to decreased porosity, rather than subsidence, accelerated erosion, or weakened vegetation which rely on different environmental changes.

• Which seismic effect increases liquefaction risk in unconsolidated sediment deposits during earthquakes?
• Which mechanism causes the formation of an accretionary wedge at a subduction zone?
• Which climatic shift occurs when weakened trade winds disrupt equatorial ocean currents during strong El Niño events?
• Which mechanism causes building foundation liquefaction during seismic activity in coastal areas?
• Which mechanism causes the formation of a graben lake when extensional forces act upon the crust?
• Which mechanism causes tsunami formation when a megathrust earthquake occurs at a subduction zone with shallow dip angle?