Hello WEAP experts,

In my WEAP model, the reservoir is the first node on the river. How should I determine and define Headflow in this situation?

My simulation period starts in October 2002. The reservoir began filling in 2006, and measured reservoir inflow and outflow data are available from 2009 onward. However, observed streamflow data from a hydrometric station downstream of the reservoir are available for the entire simulation period.

How should I define Headflow for the years before 2009, when reservoir inflow data are unavailable?

Thank you.

Mohadeseh,

If you want to simulate hydrology for time periods where observed headflow is not available, then you will need to calibrate the rainfall-runoff hydrology in WEAP. You would need to populate your flows using a catchment object in WEAP instead of the headflow on the river object. Then, you will need to calibrate your catchment object parameters so that it reproduces the observed flows (you can store and compare these in a Streamflow Gauge object in WEAP) for the time period where observed data is available. See the WEAP Tutorial calibration chapter for more info on how to calibrate your catchment. Once your catchment is calibrated, then you can use either your own climate data or the climate data available in Catchment Delineation Mode (see the Tutorial for help on this) to produce flows outside of the period where you have observed data.

-Doug