Subject: Questions from tutorial Posted: 1/16/2017 Viewed: 3727 times
I have started following the tutorial from start, Can you please clarify the things in "general parameters set" things like;
Kindly explain this domestic variation to me;
1. From where do these values come?
2. Why are they needed?
3. What difference do they make?
Subject: Re: Questions from tutorial Posted: 1/16/2017 Viewed: 3723 times
In the tutorial "WEAP in One Hour", you save a version of WEAP as "General Parameters Set" where "set" is a verb, in the past. You have set the general parameters (in that example, the time steps).
For the data in the tutorial such as population, per capita water demand, and domestic variation, they are all examples for the purpose the of the model. For your model, you will need to collect that data.
The data is needed because it all contributes to the water balance for the system - you need to allow WEAP to calculate the demands. These demands are then withdrawn from the river, or other supply sources you build in your model.
I suggest continuing to follow the tutorial. You will see how the information you plug in allows WEAP to calculate the results for the system.
Subject: Re: Questions from tutorial Posted: 1/16/2017 Viewed: 3718 times
Thanks very much. Your answer helps in better understanding.
One more thing is that as the data provided for the tutorial was from years 2000-2015, I don't understand what was the historical portion of the data and what is current data. Because we made a scenario named "current accounts" and then successively we are adding scenarios on and on.. which is the year we are modelling in that tutorial?
I am asking this year/time thing because I am working on WEAP in my research and I have to predict the climatic situations etc, so I am concerned about it that which years to be included and with which status(past, current)!
Subject: Re: Questions from tutorial Posted: 1/16/2017 Viewed: 3709 times
The issue of timing is a good question. When we model, we usually create two distinct time periods, a historic model, and a future model. The tutorial doesn't quite differentiate between them. I'll explain both.
1) Historic model. We often start with a historic model that coincides with a time period that we have data for - especially streamflow data. This allows us to set all the supplies and demands of the model, and then evaluate how well the model streamflow matches the observational data we have. If the match is not good, we try to adjust the model through the calibration process, so we can have confidence to use the model to study questions of the future. A historic model has a current account year (the first year of data) and only a reference scenario (years of the rest of the data). We don't use scenarios because it's in the past - we already know whether or not a dam was built, or what the population growth was.
In the WEAP tutorial, the only activity that pretends that the model is a historic model is the Data, Results and Formatting activity, which plugs in historic data. Otherwise, the model in the tutorial is viewed as a future model.
1) Future Model. After calibrating the historic model, we can change the years in the model to represent the future. This only makes sense if you have plugged in *trends* as part of your data. For example, if I switch a 2000-2005 model to a 2015-2020 model, I would want to be sure that the population data is for 2015, not the year 2000. So it's good to plug in trends for data like that (other data, such as reservoir volume capacity, doesn't change over time).
The future model has the "Current Accounts Year" which represents the year that has known data. You might even overlap a little bit with a few years of known data, for instance if I build a model today for 2015-2050, I have data for 2015 and 2016. But the scenarios start the year after the Current Accounts year (2016 in this example). We don't just use the reference scenario for the future model, we can create many scenarios to examine the impacts of climate change, aquifer depletion, or both at the same time. The scenarios as the questions "what if?" for all the development scenarios we don't know about the future. It's up to the modeler and stakeholders to define them, and study the impacts against the Reference Scenario, without the development.
Hope that helps.
Subject: Re: Questions from tutorial Posted: 2/13/2017 Viewed: 3471 times
Thanks very much for your detailed answer. It helped a lot.
Now the next question is about climate data input. My study area includes two barrages, I have the discharge data for both of them. But the problem is that tehre is only one meterological station to record climate data. So I am stuck at this point, should i input smae climate data for both of barrages or what should I do? Kindly guide me through this.
Subject: Re: Questions from tutorial Posted: 2/13/2017 Viewed: 3465 times
You will find that the reservoir nodes in WEAP do not request climate data. The climate data can be entered the catchments, if you are modeling hydrology (using climate data to produce streamflow for your model). There is data entry for evaporation, but that's not exactly climate data - you may be able to find data about it elsewhere.
Subject: Re: Questions from tutorial Posted: 2/16/2017 Viewed: 3452 times
Thank You, Stephanie!
Subject: Re: Questions from tutorial Posted: 2/17/2017 Viewed: 3433 times
what value should i give if i dont have any return flows in my study area for both return flow from a demand site and consumption of a demand site?
Subject: Re: Questions from tutorial Posted: 2/20/2017 Viewed: 3393 times
Do you mean that you don't have any data for return flow? Or does the return flow go somewhere else, like the aquifer, or another river, a wastewater treatment plant?
Industrial and domestic water consumption tends to have a lot of return flow. If you really don't have data, I would say 10% consumption would be a fine estimate to start with for both. But obtaining data would be better.