Lecture 2 Flashcards
What is the Seasonal Peak Factor in Nepal
1
What is the Daily Peak Factor in Nepal
1
What is the Hourly Peak Factor in Nepal
3
Maximum Seasonal Demand formula
Maximum Seasonal Demand = Seasonal Peak Factor * Annual average demand
Maximum Daily Demand formula
Maximum Daily Demand = Daily Peak Factor * Annual average demand
Maximum Hourly Demand formula
Maximum Hourly Demand = Hourly Peak Factor * Annual average demand
Peak Factor definition
Ratio of the maximum demand to that of average annual demand of water
Peak factor formula
Peak factor = Seasonal peak factor * Daily Peak Factor * Hourly Peak factor.
Peak factor for continuous system
2-4
Peak factor for intermittent system
4-6
Maximum demand formula
Maximum demand = Peak factor * Annual average demand
Base Period definition
Base period is the period required for survey, design and construction of water supply system. Usually, base period of two to three years is adopted
Design Period definition
Design period is defined as the future period for which a provision is made while planning and designing the water supply programs. Usually, 15 to 20 years is adopted as design period.
Base period how many years
15 to 20 years
Design period how many years
2 to 3 years
How to select design period
Anticipated expansion rate of the town:
If r ≥ 2, design period is 15 years
If r < 2, design period is 20 years
(r=growth rate of population)
Arithmetical increase method formula
Pn=Po+nC
Pn= Population after ‘n’ decades
Po=Last known population
C=Average (arithmetic mean) of increase in population
Geometrical increase method formula
Pn = Po(1+r/100)^n
Pn=Population after ‘n’ decades
Po=Last known population
r=average percentage increase in population
Incremental Increase Method formula
Pn = Po+nc+n((n+1)/2)*i
Pn=Population after ‘n’decades
Po = No. of present (last known) population n = No. of decades
c = Average (arithmetic mean) of increase in population
i = Average incremental increase
Decreasing rate of growth
??
Fire demand limit of lpcd
Not more than 11lpcd
National Board of Fire Underwriter’s formula
Q = 4637sqrt(P)(1-0.001*sqrt(P))
Q = quantity of water in l/min
P = Population in thousands
J.R. Freeman’s formula
Q = 1136*((P/5)+10)
Q = quantity of water in l/min
P = Population in thousands
Kuilching’s formula
Q = 3182*sqrt(P)
Q = quantity of water in l/min
P = Population in thousands
