Dear Forum Members,
I would like to seek your assistance regarding an issue I am facing in my master's thesis, which I am conducting using the WEAP software.
My research focuses on hydrological modeling of the Lualaba River Basin. During the calibration of the model using in situ data and applying the Soil Moisture Method in WEAP, I encountered difficulties in certain areas. Specifically, the model fails to adequately reproduce the observed streamflows, resulting in very low or even poor Nash–Sutcliffe Efficiency (NSE) values, despite several attempts at manual calibration.
It is important to note that these difficulties mainly occur in wetland areas, marshy zones, or lacustrine environments. I would greatly appreciate guidance from anyone who has experience working in such environments and could advise on possible approaches or parameter adjustments to improve calibration performance in these specific contexts.
My second concern relates to the automatic calibration of the model. In my thesis, I intend to use both manual calibration (which I have already conducted, despite the challenges mentioned above) and automatic calibration, in order to compare the results and strengthen the robustness of my analysis.
I would be very grateful if anyone with experience in automatic calibration using WEAP could share their insights or recommendations to help me better structure this step.
Thank you in advance for your time and support.

Stephane SIBITALI
Stephane.sibitali@unikin.ac.cd
Kinshasa, Democratic Republic of the Congo

Stephane,

Our best resources for learning more about calibration are pages 212, 221, and 222-226 in the catchment calibration chapter of the Tutorial, plus our YouTube lessons on calibration: https://www.youtube.com/watch?v=Notx1vfeRCk. Study your results for soil moisture (z1 and z2)- make sure that the soil moisture levels follow a believable trend and are not consistently at 0% or 100%.

For information on automatic calibration tools, we have the PESTand the Model Inspector calibration tools. The PEST calibration tool is accessed under Advanced --> PEST Calibration, with a tutorial chapter for Snow Hydrology and PEST Calibration. The Model Inspector calibration tool is described on our YouTube channel: https://www.youtube.com/watch?v=Notx1vfeRCk&lc=UgzcXOePTuvAWINNIjx4AaABAg.

I'm afraid I don't much much specific advice for wetlands. Off the top of my head, you'd have to consider the runoff coefficient would act like open water if there is water on the surface. And you'd have to think about if the water in the area is infiltrating into the groundwater easily or if the groundwater table is often saturated. My best advice would be to search for existing publications on WEAP looking at this topic: https://www.weap21.org/index.asp?action=216

Hope this helps!
-Doug