An-Najah National UniversityCivil Engineering Department

 Analysis of the Water Distribution Network of Nablus

Old City using EPANET program 

Submitted by :Magd Abd Al-haq

Supervisor: Dr. Mohammad N . Almasri

2011

The importance of water distribution networks

•water distribution networks are used to transmit water from the resources to the consumptions.

•WDNs decrease the effort, time, cost and make the life easier

• The efficiency is very important, and to check on this, a hydraulic analysis is carried out.

The main objectives

The main objective in this project is to make a hydraulically analysis of WDNs of Nablus old city using EPANET under

the following two different scenarios :

1-existing steady-state condition2-transient-state condition

Description of study area•Nablus is a Palestinian city in the northern of West Bank , In the center of Nablus lies the old city.

• The population of Old City about 12000 persons in 2010

• The area of Old City is .45 km2

•The city stands at an elevation of around 550 meters above the sea level , Old City elevation between (525-573)meters

Input Data•Convert WDN from AutoCAD to EPANET

•The length for all pipes: by return to AutoCAD WDN , I measure the lengths of pipes and then enter them to EPANET

•Elevation of the nodes :By return to AUTOCAD contour map

:Diameters•

By return to AUTOCAD WDN

• Demand

•Enter the Reservoir and its total head

•Enter the pump:

• Hazen-Williams Coefficient depend On the age & type of pipe.

and then made pump curve to enter flow and head

• Demand: By making some calculation I find the demand such as→Population density= total population/area of Old City

→Divided the total area into zones then calculating the areas of every zone then make our calculations on every zone that is Population=area(m2)/Population density•

•Total consumption= Population* Per capita daily water consumption•Base Demand= total consumption/(1-loss%)

→find the base demand on every node by Demand(region)/sum of node that serve this region

=demand for the node from this region→convert unit from (L/d) to (m3/hr) by multiply all base

demand by (1/24*1000) =.000042

Existing steady – state analysis

Results

• Pressure

There is no negative pressure in WDN for Nablus Old City

The highest value of pressure is 200 m.

The lowest value of pressure is 140 m.

Existing steady – state analysis

Existing steady – state analysis

•Velocity

Values of velocity in Nablus Old City range from (0-2)m\s

We noted the velocity is low and not exceeded (3)m in any pipe that mean the pipes diameter is large, and the zero velocity return to that the network is new and the flow is relatively low

Existing steady – state analysis

Transient– state analysis

•DemandIn order to find the demand at transient state consumption factor should be entered to patterns

Transient– state analysis

Results I took the results at peak factor (at hour 6)

• Pressure

In transient conditions (hour 6), pressure range between (100-150),because whenflow increases pressure decreases ,and there is no negative pressure

Transient– state analysis

Transient– state analysis

Value of velocity range between (0-2.5)m\s , No value was above 3m,that when flow increases velocity increases

•Velocity

Transient– state analysis

Discussion

-For existing steady state conditions:

•Not all the velocity values are within the acceptable range of(.2 -3m\s) there are alot of pipes that have velocities less than the minimum permissible limit , this is due to large diameters of pipes compared with

its demand be served.that when flow decreases velocity decreases .

*The pressure at nodes must not be less than 20m and that what our network satisfies

For transient state condition:-

As we notice the population of the old city decreases not increases so we take existing transiate condition instead of future condition consider peak factor from pattern that at 6-8 a.m we notice that the flow increases at that time so the velocities increases and the pressure decreases but all are with acceptable limits and this means do not have proplems relating to the pressure in this network

Recommendation

There is no recommendation ,velocity at nodes withen acceptable range (.2-3)m/sec and pressure withen accptable range (no pressure

less than 20m