$4.$ Consider a $\backslash (28\backslash$mathrm$\{$~km$\}^\{2\}\backslash )$ catchment.

$($a$)$ Given the observed streamflow response to a $1-$hour rainfall event below, assuming a constant base$-$flow component of $\backslash (3\backslash$mathrm$\{$~m$\}^\{3\}/\backslash$mathrm$\{$s$\}\backslash )$ and constant rainfall intensity during the event, determine the $1-$hour unit hydrograph for the catchment.

$($b$)$ Using the unit hydrograph derived in part $($a$)$ above, determine the peak streamflow $($in $\backslash (\backslash$mathrm$\{$m$\}^\{3\}/\backslash$mathrm$\{$s$\}\backslash ))$ resulting from the rainfall event provided below.

Answers: $\backslash (\backslash$square $\backslash )$