Adding water quality data

A sample network was built up previously and this will be used to demonstrate the use of water quality modelling.

This stage of the lesson assumes that a treatment chemical is to be added to one of the boreholes (KBH_2) at a fixed rate of 10 mg/litre. The control data is adjusted for that node and a water quality simulation is run.

1. Choose Open model group from the File menu. In the list of objects click to the left of 'Tutorial', click 'WQ' and then Open.
2. Open the 'Newtown WQ' network.
3. Open the WQ Base Control to associate it with the network.
   • Zoom in on the area around borehole KBH_2.

     

4. Add a treatment chemical at the borehole:
   • Select the (Properties) tool and click KBH_2 to display the borehole's properties. The properties sheet shows that initially there is no water quality data for the node.
   • In the Water Quality section, add an Initial Concentration of 10 mg/l.

     

   • This level of chemical will now be added to all water pumped from the borehole.
5. Display the properties for a pipe. The properties sheet includes two water quality parameters, the default values for which have been derived from research. The bulk coefficient is a reaction rate parameter used to calculate the change in concentration of a substance as it reacts with material in the bulk flow. The bulk coefficient has a negative value if the concentration of the substance grows over time, and a positive value if the concentration decays over time.The wall coefficient is a reaction rate parameter used to calculate the change in concentration of a substance as it reacts with material along the pipe walls. The wall coefficient has a positive value if the concentration of the substance grows in time, and a negative value if the concentration decays in time.

   

6. Commit the WQ Base Control data, commenting appropriately. Close the GeoPlan view.
7. Create a run using the new data:
   • Right-click the Newtown Control Simulations group and select New | Run.
   • Enter a Run Title of 'WQ Run 1'.
   • Drag the 'Newtown WQ' icon into the Network box, the 'WQ Base Control_1' control object into the Control box and the Profiles demand diagram icon into the Demand Diagram box.
   • Change the Start date and time to 1 October 1998 00:00 and the End date and time to 2 October 1998 00:00.
   • Set the Timestep to 5, the Maximum Iterations to 50 and the Computational Accuracy to 1 l/s.
8. Specify the water quality parameters:
   • Select Water Quality from the Run Type drop-down list. The Water Quality Options dialog is displayed.
   • Set the Trace Node to KBH_2.
   • Leave the Stagnant Water Flow Threshold as 0 and the Water Quality Timestep as 0. There is an option to drag in a Solute Data item. This can be used if the default values are not suitable.

     

   • Click OK.
9. Run the simulation:
   • Click Run Simulations.
   • When the simulation is complete, close the Output window.
   • Close the GeoPlan view.

The next stage investigates graphs of the simulation data and demonstrates the use of a water quality theme.

Back to flowchart Water quality graphs

Water quality parameters

Water quality simulations