1.   Purpose and objectives

     PC-QUASAR is a water quality and flow model for river networks. It is designed for use by such bodies as river authorities and water or sewerage utilities to help manage river water quality.

2.   Description

     PC-QUASAR is a model which describes changes in water quality over time. It provides a method for the easy comparison between the existing state of a river and the state which would exist after a change in the river network, whether planned or due to some unplanned event. It enables pollution pulses to be tracked downstream.

     PC-QUASAR models a river as a series of reaches, usually defined by the locations of tributary confluences, weirs, public water supply intakes or effluent discharges, and can be run in two different modes. In planning mode the model can provide distributions of flow and quality at key sites, enabling maximum effluent levels to be set to maintain river quality. In dynamic mode PC-QUASAR provides river flow and water quality estimates at each reach boundary over a period of time, allowing proposed changes in the river's use, flow or quality to be assessed.

     During their passage through a reach the concentrations of water quality determinands are modified according to instream physical, biological and chemical processes. The following determinands can be 
modelled: river flow, ammonia, pH, nitrate, temperature, E.Coli, biochemical oxygen demand, dissolved oxygen, conservative pollutant or tracer.

     Using any combination of observed or specified parameters, PC-QUASAR can be used to predict the effects of real or potential changes to the use of the river.

3.   Input

     Observed river data from an ASCII file, and/or direct editing of parameters.

4.   Output

     In planning mode, cumulative frequency and distribution data which can be exported to a spreadsheet or a statistical package. In dynamic mode, simulated water quality and flow, either as a profile along the river system or against time at a particular site.

5.   Operational requirements and restrictions

     PC-QUASAR is a Windows® 3.1 compliant package. It will also run under Windows® 95 and Windows® NT. Minimum requirements are a PC with 386 processor and 8MB RAM, but a PC with 486 processor and 16MB RAM is advised.  An SVGA monitor is required. Any Windows® supported hard copy device may be used for output.

6.   Form of presentation

     Disks and manual.

7.   Operational experience

     Has been applied in various locations.

8.   0riginator and technical support

     Software Sales and Support, Institute of Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire OX1O 8BB.

9.   Availability

     The software is for sale. A free information pack is available from the UK HOMS Office, Centre for Ecology and Hydrology, formerly the Institute of Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB.

10.  Conditions on use

     Software use subject to licence agreement.