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Meetings 10 and 11 (Interim Calibration Results July 12, 2017)
Mr. Anderson,

Thank you very much for your very detailed reply. It's been a very long time since I studied the sort of math that is part of the modeling process, so it's not my intention to question every little detail presented to support the model results. I do have a concern about using models for conclusions that are beyond their capabilities. I have been reading a book and papers authored and coauthored by Mr. John E. Doherty. In that book and papers a great deal of emphasis is placed on "expert knowledge" and subjective thinking. This supports my view that complex, environmental modeling is as much of an art as it is a science.

It is a fact that the reason that we have SWUCA and the CFWI effort is because the "traditional" water resource has been over permitted. Who has been in charge of consumptive water use permitting since the early 1970's? The answer is the water management districts. Who is now in charge of producing a model upon which critical water management decisions will be made? The answer is again the water management districts. If we agree that "expert knowledge" and subjective thinking are important in shaping a model, it's easy to come to the conclusion that the water management districts may not be the best choice for producing, interpreting and using an important environmental model.

As peer reviewers, your job cannot be limited to just ensuring that you agree with the techniques used, but you must fully participate in determining which water management decisions the model is most useful. Nick Sepulveda once responded to one of my questions saying that he only provides a "tool"; how it is used is not his concern. Clearly, this is not an attitude that can or should be adopted by you as peer reviewers.

We also must remember that this is not simply an academic exercise. There are real world consequences at stake. In Mr. Doherty's book on PEST, he talks about environmental monitoring as a possible way of mitigating model errors. This may sound good to theorists or ivory tower dwellers, but its likely that millions of dollars will have been spent to test a theory. That is not an acceptable risk to take with tax payer money.

Like it or not the modeling effort with which you are involved will have far reaching repercussions for generations to come. Because of this importance, I will be watching and commenting as the model progresses.  

Thanks again,

Edward McDonald
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Meetings 10 and 11 (Interim Calibration Results July 12, 2017)
The following is for the three peer review panel members (Pete Anderson, Lou Motz, and Mark Stewart( to discuss. I am looking at Layer one (the surficial aquifer system) and in particular the simulated mass balance. The graph (map) that shows L01_RECHARGE_INYR  is very confusing. The term recharge is being used differently then what I am used to seeing. My interest is Polk County. We know that the area of prime recharge is along the ridges. In fact, recharge only averages about 5 to 10 percent of total rainfall. Most of the rainfall is lost to evaporation and what's left travels along the surface of the ground.

Are any of you familiar with USGS publication SIR 2006-5320-Hydrology of Polk County, FL? I am attaching an excerpt from that report that addresses the surficial aquifer in Polk County.

Please address why there appears to be  so much difference between the model output and what is normally presented.

Thanks for your help.

Edward McDonald
Auburndale, FL
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Meeting 7: Conceptual Model Follow up - December 13, 2016
I would like to discuss the history of the expanded ECFT model. If you look at the 2015 Final CFWI RWSP Document, Volume 1A you find a section on the ECFT model. In particular, I would like to look at Table C-1. This table represents a comparison of calibration results between the  USGS ECFT model and  the HAT's efforts to "improve" the model. I am only going to look at layer one at this time as this is where all of the "action" occurs.

Per Table C-1 there are 289 monitoring wells for layer one. The original calibration results for the USGS ECFT were 201 wells within 2.5 feet of observed and 269 wells within 5 feet of observed. How much better were these numbers after the HAT's rework? Again, per Table C-1, 5 additional wells calibrated to within 2.5 feet and 1 additional well calibrated to within 5 feet of observed. Not much of change and any "improvement" could be attributed to random error.

These results also indicate that 20 wells could not be calibrated to within 5 feet of observed level. These very large errors are not surprising when you understand that the model is made up of over 180,000 grids and data only exists for 289 SAS monitoring wells.  

As I have indicated in the past, the model may be a good planning (conceptual) tool, but any other use must be carefully evaluated. Also, due to the high levels of uncertainties of the model, any use must lean towards a conservative interpretation that best protects the water resource.
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Meeting 6: Conceptual Model Follow-up - December 6, 2016

I certainly appreciate the time and effort that Mr. Barceló put into responding to my questions, but the question of accuracy has never been addressed.

How accurate does a model need to be to be useful in meeting its intended function? Back in 1994 the USGS published report 94-4254 with the title “Analysis and Simulation of Ground-Water Flow in Lake Wales Ridge and Adjacent Areas of Central Florida”. In that study, residuals were established such that 68 percent of all simulated heads must be within plus or minus 2 feet of observed surficial aquifer heads and lake levels. Intermediate and Upper Floridan Aquifer heads were to be within plus or minus 5 feet of observed levels.

The stated calibration goals for the ECFTX model is 50 percent of the wells are to have a residual within plus or minus 2.5 feet. There are no stated goals for lake levels.

So based on the above, it would appear that calibration goals are somewhat arbitrary as there is considerable difference between the two examples listed.

Back when I first heard about the ECFT model I was very excited. I thought finally we would have a very scientific way of managing our water resources. I have researched modeling efforts and I now know that models are a very good planning level (conceptual) tool, but they are not accurate enough to be all that useful. I fully support the development of hydraulic models, but we must be very careful in how the results are used. When you consider how complex the groundwater system is and how little actual information there is to provide "real" input data for each model "grid" it's no wonder that a "success" is measured with a water level difference of up to 5 feet between observation points. 

The final model report must clearly state its level of uncertainty, its capabilities and the additional work that will be required to improve the model's accuracy.

In the introductory section of the USGS report for the ECFT model, Mr. Sepulveda lists the following: "The purpose of this report is to describe the hydrologic flow system and water budget in east-central Florida (fig. 1) from 1995 to 2006, a time period associated with a wide range in hydrologic conditions in east-central Florida. Specifically, this report documents the development of the groundwater flow model used to (1) refine the conceptual understanding of the water exchanges between the surficial aquifer system (SAS) and the FAS and (2) improve the estimates of the recharge rates to the SAS from infiltration through the unsaturated zone." Any other use of the model, as prepared by Mr. Sepulveda, would be outside of its intended scope.

Edward McDonald
 

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Meeting 6: Conceptual Model Follow-up - December 6, 2016
I would like to comment on the December 6, 2016 Technical Memorandum that was prepared by the CFWI HAT.

1. Each peer review expert should review this document and insure that it accurately and fully addresses all issues raised in the preceding  meetings. If not, I would recommend that each of three experts respond in writing with clarifications and/or exceptions.

2. The acronym PEST is used extensively. As with any "tool" it has its limitations and "best uses". The attached document from the USGS appears to be a good description of how the PEST approach applies to groundwater modeling. Is there any disagreement with the use of this document?

3. I don't see any mention of an uncertainty analysis. Shouldn't every "calibration" effort be accompanied by an evaluation stating the level of uncertainty?

4. Groundwater models are a unique combination of very detailed mathematics and modeler "judgement". Please confirm that the three, expert panelists will be able to review and comment on all aspects of the ECFTX model (including the conclusions) and not just the "approach".

5. I am very concerned about the wording of the paragraph with the heading "Lower Floridan Aquifer Discretization". I agree that the knowledge of the LFA in the Central Florida area is very limited. The fact that the SWFWMD is looking to construct additional exploratory wells is testament to this fact. I completely disagree with the statement that the LFA is important as future demands will be met via withdrawals from the LFA. No one knows whether the LFA is capable of supplying new water to meet future water demands because the flow of water within the LFA is not understood. If the LFA is recharged from a downward flow of water from the UFA then there would be no benefit of using the LFA as an alternative water source. The statement that the HAT will do what is "appropriate" is not acceptable. The point of a peer review is to remove any bias that members of the HAT may have due to any political pressure or preconceived ideas.

6. Baseflow is a very important concept and one that is very difficult to approximate. If there is more than one way to approximate baseflow, wouldn't the correct approach be to calculate baseflow using at least two different methods? This way the level of confidence (uncertainty) could be determined. There is an old saying that goes something like this: A man with only one watch knows exactly what time it is, while a man with two watches is never quite sure."
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Meeting 4 Conceptual Model (In person meeting) - October 18, 2016
Thanks again, Mr. Andersen. for your very thoughtful response. In general, it's has been my experience that the folks responsible for the CFWI RWSP (including the modeling work) are not interested in hearing alternative points of view from the general public. That's why I am counting on you and the other two reviewers of the model to "keep-them-honest". The perfect example of my complaint is that I have asked for and never received any sort of minutes to the meetings that you have had in regards to the modeling effort. You and your colleagues have prepared many written questions and I have no idea how, if or when they were addressed.  I worked in the professional field for over thirty years and I can't imagine a technical meeting without written records of what was discussed, the answers given and the "next-step" direction. There is a great deal of time, money and politics at stake with the CFWI and the ECFTX model is at the heart of everything.
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Meeting 4 Conceptual Model (In person meeting) - October 18, 2016
First, Mr. Anderson, thank you very much for your very detailed reply to my questions. Your response confirmed and enhanced my basic understanding of model calibration. I would like you to follow-up on one point that you made and that is the difference between input data and observational data. To me, input data is anything that the model uses to simulate or approximate the real world. In other words, it is known information about the world that you are trying to model. I don't know how this differs from observational data.

One final comment involves a sensitivity analysis. I believe it is true that all input data is not of equal importance or weight. Isn't it true that some input parameters can vary wildly and have very little impact on the critical outcomes (output of the model) while small changes in others can have significant impacts?
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Meeting 4 Conceptual Model (In person meeting) - October 18, 2016
Is the AFSIRS approach to estimating ET curremtly used throughout Florida by all five WMDs? Is it used though out the US? Is it the accepted "gold standard" through out the world? My research indicates that it was mostly worked on in the early 2000's. Has there been any improvements, enhancements, modifications, etc. in the last 10 years? If so what are they?
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Meeting 4 Conceptual Model (In person meeting) - October 18, 2016
Apparently there have been at least four meetings where the three peer review experts have made comments to the ECFTX model. Where can the minutes to these meetings be found?
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