Subject: Size of catchement to model Posted: 9/9/2011 Viewed: 26698 times
I am working in a rural basin which I have catchment areas are in 1000 sq.km. Can I use WEAP to model water allocation in such large catchments?
Dr. Devaraj de Condappa
Subject: Re: Size of catchement to model Posted: 9/9/2011 Viewed: 26671 times
You can even use WEAP to model much larger catchments (like several 100,000's km²).
To my knowledge, the most important criteria to decide upon the size of the catchment you'll model is the available data and objective: you can model any size as long as you have data (input data and calibration data) to set the modeling and, of course, it satisfies the requirement of your analysis.
For instance, if I have a lot of data (rainfall, streamflow, soil characteristics, geology etc.) and I need a precise spatial analysis, then I would discretise my large watershed into several small catchments (for instance of about 100 km²).
If I don't have much data and / or I'm more interested by a global spatial analysis, then I may consider just 1 single large catchment (the whole watershed, of about 1,000 km²).
Hope it helps.
Devaraj de CONDAPPA
Associate of the Stockholm Environment Institute – US Center
Mr. Dumindu Jayasekera
Subject: Re: Size of catchement to model Posted: 9/10/2011 Viewed: 26652 times
Thank you very much for your explanation and answer.
The purpose of using WEAP is to model hydrology and water allocation in the basin. I don't have much of data (since it is a rural basin). Also I have couple of reservoirs and demand sites too. I get your point and I am using same method you described and I have discretised the basin into several thousand sq.km size catchments since the whole area of the basin is about 18,000 sq.km. Also, I am more interested about spatial variation of precipitation in each catchment.
Eng. Alberto Vivas Narváez
Subject: Re: Size of catchement to model Posted: 10/30/2011 Viewed: 25959 times
I totally agree. It is important the size of the catchment but the objectives pursued