Dear all

The lack of cooperation and the sharing of data, are among the problems encountered in the management of transboundary surface water
Please is it possible to do the study knowing that I have only the downstream flows (Algeria zone) but the head flow upstream is still unknown (Morocco zone),
if not, can I just limit the study to the area of my country (Algeria)
My best regards .

Dear Bekhta,

Do you know the headflow upstream of the area that you want model, for example, from a streamflow gauge? In order to make a water balance, WEAP needs to know the water quantity inputs to the system. You could do this either by estimating the future headflow that comes from Morocco based on past streamflow gauge records. Because streamflow is likely a highly uncertain variable, I would recommend using the Water Year Method and examining several possible future sequences (see the Tutorial chapter "Refining the Supply." The tutorial is available at www.WEAP21.org/tutorial).

You could also use a DEM model to calculate the catchment area and use rainfall to determine the supply to the river in Morocco - but you would also have to estimate any potential Moroccan withdrawals, so there could be a lot of uncertainty.