Subject: water demand, supply requirement and supply delivered Posted: 9/24/2013 Viewed: 13539 times
I am working with our Zambezi WEAP model, and we are using the "Irrigation Demands only" (simplified coeffient method) for irrigation demand. We have entered losses ("Losses to system") in all of the transmission links for each irrigation area of 50%, but the resulting water demand, supply requirement and supply delivered are all the same. Shouldn't supply delivered by higher to compensate for losses (assuming there is enough water in the river to supply the abstraction)?
Subject: Re: water demand, supply requirement and supply delivered Posted: 9/25/2013 Viewed: 13538 times
There is a distinction between Transmission Link losses and Demand Site losses.
Transmission Link Losses will increase the amount of water that must be pumped from groundwater or withdrawn from surface water, but will NOT increase the Supply Requirement or Supply Delivered, as you have found. On the other hand, Demand Site Losses (there is no Catchment Losses variable) will cause the Supply Requirement to be higher than the Water Demand, and be reflected in the Supply Delivered amount.
If you look at the Transmission Link Inflows and Outflows report, you will be able to see the losses in the transmission links. Those losses are also shown in the Outflow from System report.
Subject: Re: water demand, supply requirement and supply delivered Posted: 9/25/2013 Viewed: 13535 times
Thanks for the reply.
I want to be able to compare actual abstractions (including transmission link losses) to published data on abstractions. But when I select an transmission link and try to look at outflows and inflows, I am only seeing outflows. I have chosen a sub-basin where there is only one river, one irrigated area, and one transmission link. But no inflows show up in the source marked with that river name, only outflows to the irrigated area.
More generally, is there a way to show actual abstractions for each irrigated area?
Subject: Re: water demand, supply requirement and supply delivered Posted: 9/25/2013 Viewed: 13534 times
The reason it is only showing the outflows is because it is filtered to show only Selected Sources and Destinations. Change this to All Sources and Destinations (a combo box just above the legend).
To see the actual abstractions, look at the Transmission Link Flows report. It shows the flow into each transmission link, which will include any losses.
Topic "water demand, supply requirement and supply delivered"