A - Land-use Change and Flood Risk Flashcards
What is the potential hydrological response to removal of trees and vegetation?
Decreased evapotranspiration and interception; increased stream sedimentation.
How does initial construction of houses and streets impact hydrology?
Decreased infiltration and lowered groundwater table; increased storm flows and decreased baseflows.
What is the effect of complete residential, commercial, and industrial development on hydrology?
Decreased porosity, increased peak discharges, and increased flood damage potential.
How do storm drains and channel improvements affect floodwaters?
Provide local flood relief but may aggravate downstream flooding.
Where does urbanization impact drainage basins most significantly?
In the lower part of a drainage basin.
How does deforestation compare to urbanization’s effect on hydrographs?
Both reduce interception, increase overland flow, and shorten lag time.
What impact does deforestation have on flood risk?
Increases flood risk with higher peaks and reduced recurrence intervals.
Why might deforestation be more widespread than urbanization?
Occurs for land-use changes like agriculture, industrial development, and tourism.
List three causes of deforestation.
Agriculture, industrial development, and urbanization.
What is channelization?
Creating new, often straight channels to speed water movement.
How does enlarging channels with levees affect peak flow?
Allows rivers to carry more water, increasing peak flow.
What is the purpose of channelization and straightening?
To remove water from an area and reduce flood threat.
