Flooding and river management

The hydrograph shows the River Wenning after a storm. What is the lag time?

On a storm hydrograph, what does a steep rising limb show?

A town is built over fields in a river's drainage basin. What happens to the river's lag time and peak discharge after heavy rain?

After a week of rain, a smaller storm causes a flood. Which physical factor best explains this?

Why does steep relief in a drainage basin increase flood risk?

Which of these is hard engineering to reduce river flooding?