The Temnporal Variation global database allows for the definition of daily and hourly temporal correction factors used for dry weather flows and pollutants. The factors are ratios of the actual value to the average value for the time period. These numbers may be derived from observed flow variation patterns.


 

Daily Multiplier

Multiplier of the average daily value for the value on a particular day of the week. i.e. the ratio of the daily value to the mean daily value. Typical daily flow variations are shown in the following table:

Day 
Ratio of Mean Flow
Sunday 0.96
Monday 1.08
Tuesday 1.04
Wednesday 0.92
Thursday 1.03
Friday 1.00
Saturday 0.96 

Hourly Multiplier

Multiplier of the average hourly value for the value on a particular hour in the day. i.e. the ratio of the hourly value to the mean hourly value. A representative hourly flow variation is shown in the following table:

Hour of Day
Ratio of Mean Flow
20.50
30.50
10.52
40.52
110.60
12 am0.62
50.77
60.77
90.80
100.80
70.95
80.95
51.10
61.10
31.20
41.20
1 pm1.30
21.30
12 noon1.35
71.38
101.38
111.38
81.48
91.48