Subject: Estimation of scenario Posted: 3/12/2019 Viewed: 2819 times
Hi, WEAP members
I have created two scenarios such as, climate change and irrigation growth scenario
I have two questions on the above scenarios:
1) What are the methods to estimate climate change for the purpose of input to weap model? What are the useful data for estimating climate change?
For example, I was tried to understand how to use the “water year method” to analyze climate change but I’m confused to use it. Please clarify it well and what are the procedures to identifying water year type (Very Dry, Dry, Normal, Wet, and Very Wet)
2) Can I assume irrigation growth scenario as small, medium and large scale irrigation schemes without considering the ability of the watershed to satisfy potential water demands? Is it possible to guess irrigation increase activity as small, medium and large scale irrigation for future plan?
Thank you so much!
Ms. Anne Hereford
Subject: Re: Estimation of scenario Posted: 3/14/2019 Viewed: 2801 times
For climate change projections, please see the forum post titled "Future CLimate Data" from May 2018.
As for the water year method, this can be used to model different sequences of wet and dry years, simulating potential droughts, etc. Looking at Water Year Method under Hydrology in the Data view of your model, make sure you are looking at one of your scenarios (and not Current Accounts. You can choose between them in the dropdown at the top of the window.) Here you can define A normal year is set to have a multipler of 1. You can change the multipliers for Wet, Very Wet, Dry and Very Dry years. For example, using 1.2 for Wet will mean that each year that you define as "Wet" will multiply all flow data by 1.2. Once you have defined your multipliers, you can move to the sequence tab to tell WEAP how each year is defined. If years are in the future, you're just asking WEAP "What will happen if...?" So, if you want to model an 8-year drought your sequence might be 2000-Normal, 2001-Wet, 2002-Normal, 2003-Normal, 2004-Very Dry, 2005 Very Dry, 2006 Dry, 2007 Very Dry, 2008 Normal, 2009 Very Dry, 2010 Dry, 2011, Dry, 2012 Normal, 2013 Very Wet, etc.
Once you set Definitions and Sequence, you will need to tell WEAP to use the Water Year Method in the Headflow for your rivers.
2) You can certainly have different scenarios for small-, medium-, and large-scale irrigation increases. However, you will need to enter values to represent these increases. Check out the Key Assumptions chapter of the WEAP tutorial if the small, medium, and large increases will effect multiple parameters in your model.
Mr. Henok Demissie
Subject: Re: Estimation of scenario Posted: 3/18/2019 Viewed: 2789 times
Dear Anne Hereford