QUESTION $2[30$ Marks$]$

The census data for a town are given in the table below.

$\backslash$table$[[$Census Year,$1999,2009,2019],[$Population$,35000,78000,115000],[\backslash$table$[[$Annual water$],[$demand $($Million$],[$Liters Per$],[$Year$)($MLY$)]],5260500,11790900,17260100]]$

a$)$ Calculate the Average Daily Demand $($ADD$)$ for this town in litres per day $($LPD$).$

$[5$ marks$]$

b$)$ Calculate the EPANET base demand for this town in litres per hour $($LPH$)$ if the Maximum Day Demand has an EPANET multiplier of $1\mathrm{.}8.$

$[5$ marks$]$

$3$

c$)$ Using the logistic model, forecast the population of the town in the year $2029$ and $2025$ if it is known that the annual population growth is $1\mathrm{.}6\%$ per annum. $[15$ marks$)$

d$)$ What will be the Peak Hour Demand in the year $2025$ if it has an EPANET multiplier of $2\mathrm{.}7?$

$[5$ marks$]$

The formula sheet is given below.

$P=\frac{S}{1+m*e^{ct}}$

$S=\frac{2*P_0{P}_1{P}_2-P_1^2(P_0+P_2)}{P_0{P}_2-P_1^2}$

Here $P_2$ is the population at the last census. $P_1$ is the population one before the last census and $P_0$ is the population one before $P_1$

$m=\frac{S-P_0}{P_0}$

$c=Ln(\frac{P_0(S-P_1)}{P_1(S-P_0)})$

where $n=t_2*t_1$