Yes, Sir it's a right question. Sometimes, I have also thought this but not yet explored.

Thank you Asit. But the question is So many papers are being published with that plot. I am sure that 99% of people those who are using that plot, certainly might have not read the original paper. 

Dr. Reddy as far as the application of Gibbs plot is concerned, based on my learning and interactions with some renowned hydrogeochemists, it is more valid for groundwater rather surface water. This is evident from the three domains of Gibbs plot which specifically divides water based on precipitation dominance, rock dominance and evaporation/crystallization dominance. These domains (esp. third domain) of Gibbs plot is more valid for groundwater systems than the surface flowing water systems.  Yes you are right that retrieving original paper is difficult, in general.

 Dr. Reddy, based on my studing with the hydrogeochemistry of salt lakes in Qinghai-Tibet Plateau, it is valid for recharge water and brine. This is evident from the three domains of Gibbs plot which specifically divides water based on precipitation dominance, rock dominance and evaporation/crystallization dominance. These domains (esp. third domain) of Gibbs plot is more valid for brine rather than the surface flowing water systems.  

In my opinion, shallow pore water could be illustrated was Gibbs plot. However, I didn't know the confined water is applied to the Gibbs plot or not. 

 As Dr. Manish Kumar said, it is more valid for groundwater rather surface water, this will be a great improvement in plot Gibbs. So, Dr. Manish Kumar, would you send your research article or report to me?

Thank you Dr. Manish and Dr. Chuanyong for their answer. Just you go  through the recent published papers, 99% of them is either evaporation dominant or water rock interaction. The boundaries plotted such graphs vary a lot. Further, to consider the evaporation dominance, you should also consider the depth to water table. Generally, now-a-days most of the cases depth to water table is more than 10 m. Except in alluvial region, mode of recharge is bypass/preferential flow.   In such situations, applying the Gibbs plot and concluding "Evaporation dominance", I feel little uncomfortable to read papers. I will be happy, if some one work on this topic.

 Probably this is not the correct thread to ask my question but I'm trying to understand - how the attached shape is coming in this diagram. Can anyone help me please.

I have the similar type of query like Dr. Mondal raised. If we see the original figure drawn by Gibbs 1970, there is some particular shape (find attached here). My curiosity is that why the shape like given in original paper...searching for explanation? based on what the shapes came into existence? If any one having the explanation please reply.

Dear all!

The same question is also revolving in my mind. For better understanding and more clarification on this issue, try to go through the following recent article.

Well, thank you all for the discussion. If the Gibbs diagram is to know the surface water geochemistry what is the best graphical representation for groundwater? please kindly suggest any graphical method other than Gibbs for groundwater? I have used the following graphical method in my recent publication. Is it reliable? suggest any?

Thanks Dr. Bawoke, for providing the relevant paper for the topic in the discussion. Now-a-days several researchers are working on groundwater chemistry and blindly using Gibbs plot. Unfortunately, no reviewer, questioning the usage. Marandia and Shand 2018 clearly indicated that, Gibbs plot is not valid

for groundwater. To make a plot similar to Gibbs, someone have to work on different climatic zones (as Gibbs collected the surface water from several climatic zones) and it may be possible to make a plot.

Dear Dr. Reddy, thanks for your concerned issue about unanswered questions on groundwater in general, and Gibbs plot in particular. As you suggested, we need to do a lot on groundwater analysis and producing such standard plots supported significantly with different data.

Gibbs used the diagrams to identify the mechanisms controlling the geochemistry of surface water only. No doubt.

Chemistry or quality of surface water or groundwater could be varied depending upon the sources of point or non-point contamination. Assessment of chemistry or quality is based on similar chemical parametrs of both the waters.

From this point of view, Gibbs diagrams are also applicable to groundwater chemistry without any doubt.

Nice contributions so far!

A reviewer once kicked against the use of the Gibbs plot for groundwater hydrogeochemistry in one of my manuscript submissions.

To me, the Gibbs plot can be used for both groundwater and surface water since they have close (almost constant) interactions. I agree with Dr Subba Rao's answer.

Dear Dr D. V. Reddy

The mechanism controlling chemical relationship of groundwaters based on aquifer lithology was proposed the Gibbs diagram which is having three fields namely precipitation dominance, evaporation dominance and rock water dominance. Gibbs’s diagrams representing the ratios of Na+/Na++Ca2+ and Cl−/(Cl−+HCO3−) as a function of TDS.

References

[1] J.Wu, PY. Li, H. Qian, Hydrochemical characterization of drinking groundwater with special reference to fluoride in an arid area of China and the control of aquifer leakage on its concentrations, Environ Earth Sci.,73 (2015) 8575–8588

[1] J. Xiao, Z.D. Jin, J. Wang, F. Zhang. Hydrochemical characteristics, controlling factors and solute sources of groundwater within the Tarim River Basin in the extreme arid region, NW Tibetan Plateau. Quaternary International. 380-381 (2015) 237-246

Dear Dr. Bouteldjaoui ,

Thanks for your answer. I hope you have gone through the original paper of Gibbs. Nowhere he mentioned about the aquifer water. He used this diagram only for the surface waters. I found many people are using simply for groundwater. However, someone has to check its validity for groundwater, with some cross-checks. That was my question long back.