Subject: Something wrong in modelling unmet demand Posted: 5/18/2016 Viewed: 12240 times
Dear WEAP users,
I got a problem, hope everyone know why it like that.
I'm simulating impact of climate change on water resources in my catchment.
I already successful in calibration using Soil Moisture Method.
In my catchment, the river flow into a reservoir, and reservoir supply water for downstream area.
I projected precipitation and temperature during period of 2046 - 2064 under A2 emission scenario. Thereafter, input them into WEAP model.
The rainfall tend to increase in the future, which lead to inflow tend to increase, but I do not understand why water shortage in the downstream area also increase. Normally, water shortage in downstream area should be decrease caused by inflow into the reservoir increase.
(The reservoir has operation rule, but I did not change anything with baseline and future scenario, evaporation of reservoir also was not change. Water demand keep not change)
I also used B1 emission scenario, which show that rainfall increase lead to increase in inflow, and subsequent decrease in water shortage at downstream. But A2 emission scenario totally against.
Ms. Stephanie Galaitsi
Subject: Re: Something wrong in modelling unmet demand Posted: 5/18/2016 Viewed: 12232 times
Future climate predictions frequently include increases in temperature, which would impact evaporation in the catchments, and run off to the river. Check to see if your river flow is changing overtime above the reservoir. My guess is that the flow is less, so the reservoir has less water overall, and the downstream demands are receiving less.
Another reason the shortages might increase could be that the populations in your downstream demands are growing, so the total demand is growing. Thus even if they had the same amount of water overall, there would be shortages.
Do either of these explain the change?
Mr. Quoc Pham
Subject: Re: Something wrong in modelling unmet demand Posted: 5/18/2016 Viewed: 12223 times
Thank you so much for your kind respond !
Firstly, of course I got increase in temperature lead to increase in ET, but it's not much than increase in rainfall, as you see my previous post, I said that inflow into reservoir tend to increase. Which mean that increase in ET less then increase in rainfall.
Secondly, I did not change water demand in downstream area (populations). I just used the same water demand in baseline and future scenario.
Ms. Stephanie Galaitsi
Subject: Re: Something wrong in modelling unmet demand Posted: 5/18/2016 Viewed: 12216 times
Could it be a result of seasonal differences? How are you viewing the data, by year or by month?