Dear Mr. Gomez-Romero and co-authors

I read your paper

“Methodology that Combines Multi-criteria Methods for Decision-Making, Hierarchical Analytical Process and the Goal Programming, and Their Impact in the Sustainability Evaluation of Hydroelectric Projects in Mexico”

and here are my comments

1. You speak of sustainable evaluation of hydro projects, but where do you define what is it?

I guess that what you want to say is that they must comply with the three pillars of sustainability, i.e., economics, society and environment, and in my opinion it would be correct.

Consequently, the three aspects are closely interrelated, but in the paper, especially in Figure 2, they are assumed as independent criteria. It appears like a contradiction, because you are using AHP, where all criteria must be independent, something clearly specified by Saaty.

2- I believe that the small number of criteria you use does not represent reality. There are many aspects missing, like the enormous problems to remove people, how the aquatic life of the river will be altered, how is the geology of the soil where the lake will be built, how the respective hydro plants will alter the life of populations living downstream.

No legal aspects are envisaged? I know a 1,400 million dollars plant in Canada that was halted in mid construction because of this.

There is nothing related with potential risks, or materials supply problems, or how concrete is obtained in each site, or how wild-life will be affected. How is the access to the site, what type of water turbine will be used, and many many others.

3- You speak about using AHP that demands a lineal hierarchy. Such a thing normally does not exist in real problems, although may be in some trivial problems. More often than not everything is related in vertical, horizontal and transverse relationships. You need a network for this type of work.

4- You say “it produced between 40 to 80 million displaced by the construction and operation of the dams”.

I believe there is a mistake.

It represents about 38% of the population on whole Mexico. Are you aware that the largest hydro dam in the world, the Three Gorges Dam in China, producing 22.5 Gigawatts, displaced 1.3 million people?

5- In page 6 you say “since the useful life of hydroelectric plants can be longer than 30 years (CFE 2011)”.

Yes, their life is between 60 and 100 + years.

6- The project has a good mix of professionals, and one wonders how, analyzing two criteria like C4 = Air pollution, and C5= Social benefits, using two experts in completely different disciplines, can determine a degree of importance, when the Social worker knows nothing about environment, and the Environmentalist knows nothingon social issues.

7- In page 14 you say “Finally, the eigenvectors were obtained by using the geometric mean”

I think there is a misconception here, since the Eigen Value Method is different from the geometric mean. According to some researchers, for a number of alternatives greater than 3, both results don’t coincide.

8- In page 14 you say “Table 3 presents the results by group of experts: economic and technical experts give higher priority to the economic perspective, and lower priority to that of integrity; environmental experts give higher priority to the integrity perspective and lower priority to technique; social experts give higher priority to the social perspective and lower priority to technique; Finally, integrity experts give higher priority to the economic perspective and lower priority to the environmental one”

Obviously, this is expected, because each kind of experts knows its field the better. You can see here impartial evaluation. By the way who are ‘integrity experts?

9- In the conclusion you say “The AHP allows the use of rational thinking and logical arguments to select criteria and determine weights through paired comparisons”

As far as I understand AHP is not based on rational thinking and logics arguments, but the opposite, since it is based on intuitions and no reasoning.

10- On page 20 you say “This analysis uses Web-HIPRE computing tools. The analysis makes variations in the criteria weights and shows, numerically and graphically, how the changes affect the rest of the values of the alternatives and their ranking (see Fig. 5)”

You certainly know that all criteria are considered in the evaluation of alternatives, and also, that the final result in selecting the best alternative, not all criteria participate, only those named ‘binding criteria’. According to the article, it appears that all criteria are tested, even the irrelevant, when their variation, positive or negative, do not have any influence in the alternative’s rankings. My question is, how do you know which are the binding criteria and which are those no-binding?

Hope that my comments may be of utility

Nolberto Munier