# 133

Dear Onwusameka Sonny Ogbowuokara , Tambari Gladson Leton John Nwenearizi Ugbebor, Ochuko Felix Orikpete

I read your paper

Assessing the relative contribution of various anthropogenic sources to atmospheric methane in Rivers State, Nigeria: A multi-criteria decision analysis approach

My comments

1- In the abstract you say “By incorporating expert opinions, literature reviews, and surveys, the study constructed a hierarchical model to prioritize these sources based on their impact”

The hierarchy does not prioritize sources based on their impacts but on their relative importance. The hierarchy only shows dependence.

2- On page 2 “Numerous studies in the past have developed various methodologies to determine the different sources' relative contributions to atmospheric methane levels”.

But in page 4 you say: “Despite the extensive application of Multi-Criteria Decision Analysis (MCDA) in environmental studies, a notable gap identified is that none of these studies have specifically used MCDA to assess the relative contributions of various sources to atmospheric methane”

I think that you contradict yourself, according to the first paragraph above, and because the beginning you compared CO2 with CH4

3- “Among these, our study has chosen to use the Analytic Hierarchy Process (AHP), as developed by Saaty (1977), for its robust and well-established framework in handling complex decision-making processes”

You are free to use the method of your choice, considering its respective areas of applications and ability to deal with complex scenarios, but AHP cannot handle them because its linear hierarchy.

4- “AHP is particularly suited for complex problems where multiple criteria are involved and is effective in measuring and analyzing preferences”

One of the drawbacks of AHP is precisely working with many criteria, because the workload. It does no analyze preferences.

HOW? if they are completely arbitrary? and convert those preferences using a table, that attempts to reproduce a psychological law, that is not applicable a MCDM. I refer to the Weber-Fechter Law that relates incentives with results. Obviously, preferences are not equal to incentives. The latter produce an increase in productivity (the response). Which is the effect that a preference may produce? Unfortunatelly, Saaty never explained it.

5- In page 6 “and standardized the range of the criteria using utility”

I read many times this sentence trying to discover what it means. OK, In you multiply for alternative “ j” its utility aij by criterion ‘i ‘weight or wij, you get the weighted utility of alternative “j”, how can you standardize the criteria weights, when you have several alternatives for that same criterion? If you add up the weighted values for the same alternative, and for all criteria you get the score or the relative value of that alternative regarding the other alternatives. Thus is the very well-know primitive SAW or Simple additive weighting, one of the first MCDM methods.

6- After reaching the end of your paper I am puzzled. As I understand, you have five sources or alternatives or option that produce atmosphere contamination and you want to classify them according to their relative importance. An you employ MCDM, which is a good choice.

But MCDM uses alternatives and criteria. In your case the latter could be CO2, CH4, NOx, SOx, etc., as well as temperature, evaporation, atmospheric pressure, etc.

My question is: Where are your criteria?

It appears that you applied AHP to the alternatives, but since each pair is pair-wise compared regarding a certain criterion, where is it? I remind you that this procedure corresponds to the second step of AHP, and AFTER the criteria weights have been established.

I hope these few comments may help

Nolberto Munier