How does urbanization of the upstream drainage area for a floodplain affect the 100-year flood level?
A)It lowers flood height, since the water runs through faster.
B)It raises flood height.
C)It decreases duration of the peak flood level.
D)The downstream extent of the highest flood level will be less.
E)There is no change; the flood level only depends on the total rainfall upstream.

Question

Quizplus · Accepted Answer

Urbanization typically increases surface runoff by reducing the amount of water that can infiltrate into the ground, due to the addition of impervious surfaces like roads and buildings. This leads to higher and faster peak water flows downstream, raising the 100-year flood height.

How Does Urbanization of the Upstream Drainage Area for a Floodplain