Subject: Organizing demand and supply data for a WEAP model Posted: 12/4/2021 Viewed: 4960 times
Dear Stephanie,
First I would like to appreciate your kindness, efforts and willingness to assist people with questions on WEAP.
Following this, I have these questions on the application of WEAP:
1. From your earlier responses I understood that the water year method repeatedly uses current year data. Which data are repeatedly used and which are not (climate, hydrology, demand...? What if I use timeseries data for some or all variables?
2. What are the basic factors for WEAP users to choose either the water year or the catchment method?
3. Currently I'm undertaking a basin scale study with 21 subbasins (catchments or planning units). I aggregated water demands (domestic, livestock & industrial) at a catchment level. I have a few gauging stations in the basin. The demands sites in the catchments, where the gauging stations located, are distributed above and blow the gauging stations. As the study area is very wide it is a bit complex to put the demands site by site to show whether they are above or below the gauging stations. IS there any way to have a single demand node (only for domestic, livestock & industrial demands) per catchment like this situation) and run my model? By the way I use catchment method to estimate the irrigation water demands.
4. Given my study situations (above) which approach (water year or catchment) should I use to assess the impacts of climate change on the water demand (irrigation) & supply in the study basin?
Thank you very much!
Mulugeta
Ms. Anne Hereford
Subject: Re: Organizing demand and supply data for a WEAP model Posted: 12/9/2021 Viewed: 4927 times
Dear Mulugeta,
1. You can elect to use the Water Year Method to calculate River Headflow, Groundwater Recharge, Local Reservoir Inflow, and Surface Water Inflow to Reaches. The Water Year Method allows you to set the Current Accounts data as being Normal, Wet, Dry, Very Wet, or Very Dry and to define Wet, Dry, Very Wet, and Very Dry relative to Normal. It is possible to use the Water Year Method for some supplies and use timeseries data for others. Water Year Method is not available for use with Climate variables.
2. The WEAP help suggests:
-If you want to test a hypothetical event or set of events, or wish to approximate historic patterns, or have very limited data, then you should probably select the Water Year Method.
- Your choice of [catchment] method should depend on the level of complexity desired for representing the catchment processes and data availability.
3. If I understand this part of your question correctly...You can certainly aggregate demand into a single demand node. The problem, as you hint at, is that if you aggregate demands that are--in reality--at various locations relative to your stream gauges, you may have trouble calibrating your model (depending on the volume of water demand relative to streamflow). If you have gauging stations upstream and downstream of the collection of demand sites, you could use these to help you calibrate a model with aggregated demand.
4. In WEAP, the Catchment Method is selected independently of the supply method (Water Year Method vs. Timeseries), except in the case where catchment runoff represents the headflow for a rive. So this isn't really an either/or question.
Anne
Topic "Organizing demand and supply data for a WEAP model"
