Subject: how to "delay" the flow Posted: 2/13/2007 Viewed: 36581 times
how to "delay" the flow Anne Chaponniere achaponniere <a href="mailto:a.chaponniere@cgiar.org">a.chaponniere@cgiar.org</a>Hello, I am applying the WEAP to the Volta basin (West Africa), concentrating on the rainfall-runoff routine. In the Volta basin, there is a shift of several months between rainfall and runoff signals. I am not able to reproduce properly this with WEAP's rainfall-runoff method (even exagerating values of severall parameters like the runoff-infiltration partition parameter, the GW hyd. conduc, or the crop coefficients). Any suggestions? Thanks, Anne
Dr. Spyros Michas
Subject: RE: how to "delay" the flow Posted: 9/26/2007 Viewed: 36576 times
RE: how to "delay" the flow Spyros Michas smichas <a href="mailto:smichas@hydroex.gr">smichas@hydroex.gr</a>Sounds like Volta is a very big basin. What's the area?
In my opinion, for such large basins you would need a different model, one that will do some hydraulic routing (not available in WEAP). Possibly a distributed or semi-distributed model along with some decent data for calibration can do it.
Do you have good runoff and rainfall measurement?
Spyros Michas
Dr. Mohammad Rayej
Subject: Re: how to "delay" runoff Posted: 9/26/2007 Viewed: 36572 times
Re: how to "delay" runoff Mohammad Rayej rayej <a href="mailto:rayej@water.ca.gov">rayej@water.ca.gov</a>I think, one way to "lag" runoff following a rainfall event might be through LAI (Leaf Area Index) in WEAP's two-bucket method. The bigger the LAI (i.e. more plant canopy) is, the smaller the magnitude of the runoff would be. This means more water available in the root zone which gradually contributes to a prolonged runoff event. Remember, runoff in WEAP is not only a function of LAI, but also a function of z1 (root zone moisture content). good luck !!
************************************************************** Mohammad Rayej, Ph.D., P.E. Senior Engineer, W.R. California Department of Water Resources Statewide Water Planning Branch 901 P Street, 2nd Floor Sacramento, CA 94236 (916)-653-8017 rayej@water.ca.gov
