Patterns of Water Demand Lecture 2 Patterns of Water Demand

Patterns of Water Demand The water consumption varies hourly, daily, monthly and seasonally. This variation is caused by peoples activities that differs from one hour to another during the day , and by climate conditions. Demand Patterns are diagrams that show the variation of water consumption during a certain period of time. These diagrams are based on recordings for each type of water demand (Domestic, commercial, industrial … etc). Then the diagram is plotted between the time on the X axis and the ratio of the recorded flow to the average flow on the Y axis. Demand patterns for domestic consumption are usually generated using metric readings and billing records. For other types of demand studies are made to generate the demand patterns.

House information Al Naser St. Residential Area Beach Camp well (3) Source of water Mostly (13:00-16:00) Duration of water supply 2 floors House Upper tanks Water recording 2 cold + 1 hot No. of tanks 6 Family member 2 College students, 2 school pupils Working Father Description Tank perimeter (m) Diameter (D) (m) Area m2

Consumption Q (litter ) Hour 186 4-6 15 6-8 63 8-10 28 10-12 19 12-2 9 2-4 71 50 8--10 136 10--12 12--2 31 2--4

Cumulative Consumption Hour Q (litter ) 4-6 186 6-8 201 8-10 264 10-12 292 12-2 311 2-4 320 329 400 8--10 450 10--12 586 12--2 649 2--4 680

Average consumption\ 2 hours = Consumption = 680\6 = 133.3 l\c\d Average consumption\ 2 hours = = Hour Pattern Values 4--6 3.280 6--8 0.264 8--10 1.110 10--12 0.494 12--2 0.335 2--4 0.158 1.252 0.882 2.410 0.547

Factor Time ( hr )

Annual consumption Month Q ( m3 ) January 56 February 51 March 45 April 40 May 39 June 49 July 54 August 53 September 46 October 33 November 37 December 50

Annual pattern Month Pattern Values January 1.215 February 1.106 March 0.976 April 0.868 May 0.846 June 1.063 July 1.171 August 1.150 September 0.998 October 0.716 November 0.803 December 1.085

Factor

فندق مصنع بلاط زراعي (طماطم) زراعي (فراولة) مدرسة (فترتين) مدرسة (فترة واحدة) مسجد محطة وقود التجاري الساعة 0.83 0.14 0.05 0:00-1:00 0.69 0.21 1:00-2:00 0.55 0.6 2:00-3:00 0.49 2.08 0.28 0.53 3:00-4:00 0.31 0.74 4:00-5:00 0.9 0.89 0.25 1.27 5:00-6:00 1.25 1.07 3.73 5.19 1.32 4.28 0.3 1.69 6:00-7:00 1.11 1.71 7.06 5.02 2.43 2.12 2.11 7:00-8:00 1.59 2.98 8:00-9:00 0.42 1.93 4.86 2.57 2.64 9:00-10:00 2.14 1.48 2.4 0.7 3.16 10:00-11:00 1.37 2.23 1.05 2.32 11:00-12:00 1.04 3.21 3.01 2.74 4.47 1.68 1.58 12:00-13:00 2.79 4.39 2.47 0.71 2.39 13:00-14:00 1.53 1.06 0.86 2.81 14:00-15:00 1.66 1.16 0.68 0.84 15:00-16:00 1.39 3.81 4.24 0.79 0.34 3.22 1.12 0.63 16:00-17:00 0.64 7.08 17:00-18:00 1.46 4.36 0.32 18:00-19:00 3.57 19:00-20:00 1.19 20:00-21:00 3.69 21:00-22:00 0.97 0.11 22:00-23:00 23:00-24:00

Example ( 1 ) A water supply company delivered an average annual quantity of 10,000,000 m³.On the maximum consumption day, the registered delivery was as follows : Determine : The daily pattern for the water delivery of that area. The maximum seasonal variation factor for that day. Hour 1 2 3 4 5 6 7 8 9 10 11 12 Q (m³/h) 989 945 902 727 844 1164 1571 1600 1775 1964 2066 2110 13 14 15 16 17 18 19 20 21 22 23 24 1600 1309 1091 945 1062 1455 1745 2139 2110 2037 1746 1018

Solution : Find the average daily consumption = ∑ Q / 24 = 1454.75 m³/hr For each hour, the pattern factor = Q / Qavg Hour 1 2 3 4 5 6 7 8 9 10 11 12 Q (m³/h) 989 945 902 727 844 1164 1571 1600 1775 1964 2066 2110 Factor 0.68 0.65 0.62 0.5 0.58 0.8 1.08 1.1 1.22 1.35 1.42 1.45 13 14 15 16 17 18 19 20 21 22 23 24 1600 1309 1091 945 1062 1455 1745 2139 2110 2037 1746 1018 1.1 0.9 0.75 0.65 0.73 1.0 1.2 1.47 1.45 1.4 0.7

The seasonal variation factor = 1454.75/1141.55 = 1.274. Time ( hr ) The average consumption, based on the annual figure = 10,000,000/365/24 = 1141.55 m³/h. The seasonal variation factor = 1454.75/1141.55 = 1.274.

Example ( 2 ) A water supply company delivers an annual volume of 13,350,000 m³. The maximum daily demand of 42,420 m³ was observed on 26 July. The minimum, observed on 30 January, was 27,360 m³. The following delivery was registered on 11 March: Determine: Delivery on an average consumption day and the range of seasonal peak factors. The Final peak factor diagram.

Solution : Maximum seasonal Peak Factor = Delivery on an average consumption day = Minimum seasonal Peak Factor = Maximum seasonal Peak Factor = Range of seasonal peak factors 0.75 – 1.16 To generate the peak factor diagram : Q avg = 1435 m³/hr , Ps = 1.16 /day Hour 1 2 3 4 5 6 7 8 9 10 11 12 Factor 0.35 0.454 0.52 0.675 1.172 1.328 1.5 1.553 1.564 1.525 1.391 1.383 13 14 15 16 17 18 19 20 21 22 23 24 1.32 1.338 1.446 1.555 1.686 1.661 1.571 1.174 0.984 0.657 0.546 0.486

Generate the final demand pattern for 24 hrs. Example ( 3 ) A Family of 7 members has the following Daily Consumption : Generate the final demand pattern for 24 hrs. Hour 1 2 3 4 5 6 7 8 9 10 11 Q (l/h) 25 15 34 14 70 53 12 13 14 15 16 17 18 19 20 21 22 23 47 67 95 103 57 34 38 25 And the following Annual Consumption : Month 1 2 3 4 5 6 7 8 9 10 11 12 Q (m³/d) 19.7 18.6 21.5 23.4 26.9 35.7 42.4 45.9 37.5 32.3 25.4 20.1

Solution : Calculate the maximum monthly factor from the monthly pattern. The average monthly consumption = 29.12 m³/d. So the monthly peak factor = 1.58 Generate the pattern for daily consumption : Qavg= 34.21 m3/h Month 1 2 3 4 5 6 7 8 9 10 11 12 Q (m³/d) 19.7 18.6 21.5 23.4 26.9 35.7 42.4 45.9 37.5 32.3 25.4 20.1 Factor 0.68 0.64 0.74 0.80 0.92 1.23 1.46 1.58 1.29 1.11 0.87 0.69 Hour 1 2 3 4 5 6 7 8 9 10 11 Q (l/h) 25 15 6.5 34 14 70 53 Factor 1.15 0.69 0.37 0.30 0.23 0.51 1.57 0.65 3.23 2.45 12 13 14 15 16 17 18 19 20 21 22 23 47 67 95 103 57 34 38 25 2.17 3.09 4.39 4.76 2.63 1.57 1.76 1.15 1.06 0.88 0.69

Example ( 4 ) For a given junction serves different average consumptions (Qave-2h) and patterns. Calculate the total average consumption (Residential, Commercial & Agriculture) and combined pattern for this junction. Time (hour) 0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 Residential (Qav=15 m3/2h) 0.5 0.3 2 1.5 1.1 1 1.2 0.8 Commercial (Qav=3 m3/2h) 1.7 2.5 3 Agriculture (Qav=10 m3/2h) 2.4 2.6

Equivalent Pattern Factor Time (hour) 0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 Qav Residential 0.5 0.3 2 1.5 1.1 1 1.2 0.8   (Qav=15 m3/2h) 7.5 4.5 30 22.5 16.5 15 18 12 16.25 Commercial 1.7 2.5 3 (Qav=3 m3/2h) 2.4 5.1 9 3.6 Agriculture 2.6 (Qav=10 m3/2h) 10 24 26 20 Total Qav 29.25 The Total average consumption = 29.25 m³/2 hr Time (hour) 0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 Residential 7.5 4.5 30 22.5 16.5 15 18 12 Commercial 2.4 5.1 9 3.6 1.5 Agriculture 10 24 26 20 Total Q 42.4 57.6 48 47 41.6 Equivalent Pattern Factor 0.256 0.154 1.450 1.969 1.641 0.821 1.607 1.422 0.564 0.410

Homework # 1 For Example ( 1 ), if an average leakage of 20 % is assumed. Find the daily pattern for the water consumption of that area.

Questions