Part A: Numerical questions

Marks will be deducted if you do not briefly explain the theory you employ and show your working.

Note that in the questions below, you need to use numbers from your student ID to determine certain parameter values: $W$ is largest digit from your student ID$,x$ is the smallest $($non$-$zero$)$ digit from your student ID$,Y$ is the penultimate digit from your student ID and $Z$ is the last digit from your student ID $($e$.$g$.$ for student ID H$00032967,W=9,x=2,Y=6,Z=7$ so: $Wx=92,2W=18,$ etc$).$

Question $1$

$($a$)$ Areas bounded by isohyets drawn on the map of a river catchment are shown in Table Q$1$a$.$ Determine the catchment average rainfall using the isohyetal method.

Table Q$1$a

$\backslash$table$[[$Isohyets$,$Area between isohyets, $k{m}^2$