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All Topics | Topic "Built-in BOD/DO model: modifying parameters?"
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Subject: Built-in BOD/DO model: modifying parameters?   
Posted: 2/29/2012 Viewed: 16286 times
Dears, to my purpose the built-in model would be enough, but only provided that I can calibrate its parameters (I would not like to have to link to the complicated QUAL2K, starting from the fact that I cannot understand how to modify the .q2k file).
The question then is: where are such mysterious parameters hidden? How can I modify them?

kind regards, Wendy from Colombia
Jack Sieber

Subject: Re: Built-in BOD/DO model: modifying parameters?   
Posted: 3/1/2012 Viewed: 16266 times
Unfortunately, the parameters and constants in the DO and BOD calculations (described in http://www.weap21.org/WebHelp/index.html#Dissolved_Oxygen_and_Biochemical_Oxygen_Demand.htm ), such the decomposition, reaction, and re-aeration rates, cannot be changed.

For a more complete discussion about BOD and DO models, see Lecture 19 "BOD and Oxygen Saturation" in "Surface Water-Quality Modeling" by Steven C. Chapra: http://www.amazon.com/Surface-Water-Quality-Modeling-Steven-Chapra/dp/1577666054



Subject: Re: Built-in BOD/DO model: modifying parameters?   
Posted: 3/3/2012 Viewed: 16258 times
Thanks Jack,
indeed this is not good news and sounds as no river is like another one and calibration of basic parameters is essential. I guess one has got therefore to use QUAL2K. Then a simple question: I understood that WEAP automatically prepares the datafile for QUAL2K and gets its outputs, so one in principle has no obligation to manage directly the QUAL2K data file, but just provide the required data through WEAP interface. Is this true?
It seems it is not because, once created a very basic example with just one river with constant headwater (quality & quantity) and a constant load to it, and once specified the association amongst WEAP WQ variables and QUAL2K WQ variables (in the General TAB), when trying to simulate WEAP, protests asking first to re-arrange the distance markers of reaches from downstream to upstream (a task that an automatic transfer protocol could deal in a very straightforward fashion , totally transparent to the user); then it asks for a .q2k file which I cannot find. The user guide seems to say that one has to use a QUAL2K.xls (which indeed I found somewhere), modify it and through it create the required .q2k?!

Then the question is:
- where is this .q2k file?
- if really the user has to put his hands within the odd QUAL2K.xls file, wouldn't it be simpler just to start with QUAL2K from zero, while abandoning WEAP?

Your help would be very much appreciated
kind regards, Wendy
PS: By the way, another interesting reference to the topic of river WQ modelling and calibration is as far as I know: Nardini A. and R. Soncini-Sessa (2003). "River Quality Models: Criteria for the Design of Data Collection Campaigns Aimed at Model Calibration". European Water Management on line (EWMO), September 1, 2003, Vol.1 (http://www.ewaonline.de/journal/2003_06.pdf <-- this link seems not to work anylonger, but if required I can provide the original file as it was free access)
Topic "Built-in BOD/DO model: modifying parameters?"