What is wave runup?

Wave runup refers specifically to the phenomenon where water is driven inland by waves, reaching a height that exceeds the stillwater flood level. This process is significant in coastal areas during storm events, where large waves can cause water to surge onto land, potentially leading to increased flooding and erosion. Understanding wave runup is crucial for floodplain management and the design of coastal structures, as it provides insight into potential inundation areas that may not be indicated by static water levels alone.

The other concepts addressed in the incorrect options do not accurately define wave runup. For example, the slow rise of water levels after a flood pertains to the drainage and recession of floodwaters rather than the dynamic action of waves on the shore. Similarly, the retreat of waves back into the ocean refers to wave behavior after breaking, which does not capture the concept of wave runup. Lastly, the speed at which waves travel is related to wave dynamics but does not pertain to the height or extent of water moving inland, which is essential for understanding the impact on floodplains.