Hydraulic Approach into Olden Agricultural Aqueducts at the Mexican Region of Zacatecas

Round 1

Reviewer 1 Report

The authors have done a good job of presenting their objectives and presenting data that support it. 

This reviewer was interested in seeing some of the actual water delivery systems presented rather than a generic one. 

Author Response

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Reviewer 2 Report

The study concerns the important hydraulic approach to olden agricultural aqueducts in the Mexican Region of Zacatecas. The paper shows a brief outlook of some hydraulic systems in Asia, Europe and America settled thousands of years ago. Also, a historiographic approach is made for several aqueducts built within the limits that currently constitute the state of Zacatecas during colonial times and independent Mexico in order to evaluate their transcendence for mining, agriculture, and cattle. Comments: Please reason both the novelty and the relevance of your paper goals. In conclusion please describe and reason the original developments. If possible present some information about the irrigation concepts, that were needed to compensate for the water demanded by crops. What is the novelty of the approach presented in the study? What lessons should exploiters or authorities draw from this analysis? This should be discussed in the point concerning the discussion of the results in the third section: 3. Results and Discussion. The regions in which the inquiry was conducted, What's distinctive about them? The main achievements of this article should be presented and underlined in conclusion.

Author Response

Our comments are included in a Word file.

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Reviewer 3 Report

The manuscript “Hydraulic Approach into Olden Agricultural Aqueducts at the Mexican Region of Zacatecas” has been reviewed. The article is elegantly written and pleasant to read, it presents an entertaining historical review in the introduction and, a priori, links the tradition of Roman engineering with the hydraulic constructions in Zacatecas after the Spanish conquest. However, it presents some weaknesses or inconsistencies; the article with a nice style, remains in generalities, lacking depth or justification in its affirmations.

The summary, introduction or conclusions are focused on the engineering used by the ancient Romans, and its application in the hydraulic works in Zacatecas. Specifically, the only relevant conclusion (lines 521-533) states that “during colonial times and independent Mexico, there were already engineering criteria (perhaps as technical recipes) for the design and operation of agricultural hydraulic systems using methods of conduction and distribution by open channels and ditches, and surface irrigation schemes for farming fields”

To reach that conclusion, it should be specified and justified how the Romans designed. What were their design principles for aqueducts? Roman engineering established the procedures for engineering works, on a greater or lesser scale, in the Middle Ages. Later, some civilizations such as the Islamic, heirs of Roman engineering; In medieval Spain, both traditions converged and structures for water management (canals, aqueducts, waterwheels) were developed.

Subsequently, although it is good to characterize its operation through the parameters of modern engineering, what is relevant is to verify and justify that in Zacatecas, the design parameters are within the tradition inherited from Roman engineering and executed by the colonizers. In any case, it is important to ask: What can make you think that the construction could have been different?

Continuing with the conclusions, the one that refers to the historiographical study (lines 503-510) is not reflected in the results and previous discussion; it appears in the conclusions section without any link with the historical sequence that has been presented in the section on results. On the other hand, in this historical sequence, it would be opportune to justify (although it is approximate) the dates of construction, relevance or splendor of the final development and end of use or replacement by modern water transport systems.

The rest of the argumentation of the conclusions; very well written, they are generalities that do not build real conclusions of this study.

In the presentation and location of the aqueducts, more information is required, for example, the image in figure 1 is blurred, with the scale used locations overlap. The location and physical characteristics of each aqueduct should be well identified. A delimitation of the potential irrigated surfaces (more or less approximate of each hydraulic work location) would also be convenient. In the same sense, it should be explained how data on the dimensions of the canals and aqueducts have been acquired; also if they have been documented on the cultivation practices of current producers, how structured has that data collection been?

When the authors present the “historiographical review” they speak of “a topographic survey was carried out in an attempt to ascertain geometric characteristics of all olden aqueducts, as well as to typify topographical forms of agricultural zones to which they supplied water”. Presenting the results of this study, even if it were summarized, would be very interesting to justify the flows in the aqueducts.

Also, the basic equations that characterize the operation of a canal in a permanent regime or the basic planning of furrow irrigation are presented (section 2.3). Just as these concepts are explained, why is the calculation of irrigation needs that has been followed not detailed in a basic way? Although there are the references used (lines 196-198), an explanation of the method used would be convenient.

Going back to section 2.3, Why is a 20% of the depth of the channel (freeboard) used to obtain the depth of flow? It is important to characterize the hydraulic regime (fast or slow), it is the slow regime that has been used since ancient times for the design of durable channels. In historical or current irrigation, there are many ways to systematize the land for irrigation; furrows are just one of them. Why are furrows of “0.75 m wide and 150 m long” selected?

In the results, a scheme is presented (figure 2), it would be more interesting if this scheme corresponded to one of the eight real structures/systems studied. Even better, those two that are analyzed in detail (Teul and Malpaso). A scheme of the structural typology used would also be interesting. Even more so considering that the economy in construction is a criterion, not explored by authors, that determines the chosen section. This is a basic criterion as it is said in the manuscript (lines 380-394)

The authors select two zones to explain their findings; however, the cropping patterns, usual rotations and simplifying assumptions would be interesting if they were summarized (at least in a table). Section 3.1 on “agricultural water management” is highly speculative; (some examples) Based on the fact that an irrigation efficiency of 40% is defined (the type of soil is not mentioned, or the hydraulic characteristics of the land), was it only irrigated by furrows? A 10-hour workdays tending plots is defined, this is a duration of the current working day; For irrigation tasks, in many agricultural structures throughout the world, 24-hour workdays are used. If there are no data, the difficulty of talking about water management must be recognized, but the authors seem to be trying to be too precise in the necessary flow values, simplifying excessively. It would be more reasonable to establish a probable range to justify whether the transportation channels and aqueducts were adequate. Would the agricultural areas delimited in the topographical study that has been carried out be correctly irrigated from each channel?

Probably this paper could be divided, including and extending them with sufficient justification, into two: one with the historical sequence and the characterization and the other with an in-depth analysis of the 8 scenarios.

Author Response

Our comments are included in a Word file

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The study concerns the important hydraulic approach to olden agricultural aqueducts in the Mexican Region of Zacatecas. The paper shows a brief outlook of some hydraulic systems in Asia, Europe and America settled thousands of years ago. Also, a historiographic approach is made for several aqueducts built within the limits that currently constitute the state of Zacatecas during colonial times and independent Mexico in order to evaluate their transcendence for mining, agriculture, and cattle. Comments:  Add some references, and some perspective of future work, line 605: Likewise, and as a consequence of all this, to establish criteria for waterworks’ operating with an emphasis on 606 an adequate control and enough delivery of those flow rates that, on the one hand, allow 607 optimal water productivity and, on the other hand, minimize losses of this natural re- 608 source. Ee.g. Ref. Modelling water distribution network failures and deterioration, 2017, IEEE International Conference on Industrial Engineering and Engineering Management 2017-December, 924-928. DOI 10.1109/IEEM.2017.8290027. If possible according to the journal guidelines please provide the English title of the references.

Author Response

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Reviewer 3 Report

The problems mentioned in the first review have been conveniently resolved.

Author Response

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