The Assessment of Hydrological Availability and the Payment for Ecosystem Services: A Pilot Study in a Brazilian Headwater Catchment
, Antonio Lucio Mello Martins 2, Maria Conceição Lopes 2,6, Renata Cristina Araújo Costa 6, Marcelo Zanata 3,6, Fernando António Leal Pacheco 4,6,* and LuÃs Filipe Sanches Fernandes 5,6Round 1
Reviewer 1 Report
WATER-926225 “The assessment of hydrological availability and the payment for ecosystem services: A pilot study in a Brazilian headwater catchment” MBL Simedo, TCT Pissarra, ALM Martins, MC Lopes, RCA Costa, M Zanata, FAL Pacheco, LFS Fernandes
Average and annual flow values are listed in m3/s (throughout the article) which leads to values <0.0100 which are not very human numbers. Values in engineering notation with a numerical range of 1 to 1000 and an exponent are much easier to understand. The simplest change is to convert into m3/day, shifting by a factor of 86400, so the first line of Table 1 for Sub-basin 1.1 would read “734 15.6 255 216”. Another possible shift would be to L/s with a simple shift of 1000, or “8.50 0.18 2.95 2.50” for the same line of Table 1. The same changes are required in graphs of flow with the y-axis having corresponding units.
It is also important to recognise the number of significant digits implies the accuracy of measurement. Table 1 has 5 digits reported in Sub-basin 3, for example, so implies an instrumental accuracy of 5 parts in 100,000. According to the manufacturer’s specifications (thank you for including the link) the accuracy of water velocity in uniform flowing water is 2% above 1.5 m/s (and >2% below that), so at best it is 1 part in 100 accurate. It would be better to be modest regarding accuracy of annual totals and statistics, restricting reported values to 3 significant digits.
It is not clear what Figure 10 shows. What statistic of rainfall is being described by the box-and-whiskers for each year? Is it monthly rainfall? For which sub-basins? It is clear from Figure 2 that rainfall in March has very different runoff generation than the same rain in August. The absolute amount of rainfall does not appear to be a useful summary. Perhaps in Figures 11 and 12 the authors could convert the average flow rate into millimetres depth equivalent, so that both y-axes have the same units even if they do not have the same scale, and the readers might get a feel for runoff coefficients.
The balance of the article is skewed toward physical description of the sub-basins and their annual and monthly flows over 5-years. There are 9-pages dedicated to the presentation and description of this including 10 figures and 3 tables of data. There are only 2 pages of text for the Payment for Environmental Services (PES) part of the article, with no pictures or numbers. It is not clear to the reader what the legislation for PES seeks to do. For example, if a coffee farmer has 20ha under cultivation, and the crop is worth US$1000 (~50 kg/ha @ US$1/kg for round numbers), is the farmer paid US$500 to only crop half their area so that improved environmental services are delivered downstream?
It is hinted that some recompense for land holders is required, but it is not clear. What is the possible list of environmental services that could be compensated in such a way? What hydrological investigations do the authors suggest need to be undertaken to quantify the environmental services? Are there any confounding effects/risks from climate change (rainfall and temperature changes primarily), natural disaster, insect attack that need consideration?
Author Response
Please see the attached response file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
I was enjoyed reading the manuscript by Lopez Simedo et al. The manuscript deals on the assessment of surficial water availability from four sub-basins of first order to verify the differences related to land use. The comparison among the four 1st order basins could allow the evaluation of best practices (i.e. land use change) to ensure water security assessment over time. Moreover, the obtained “best-practice” may be useful for other catchments located in Brazil.
The manuscript is fully on the scope of Water and is of interest for the journal readership.
Only few comments to the manuscript:
- please make more clear the methodological section by adding an intro to Section 2 in which summarizing “this was done for “ and after sub-section “2.1 Flow monitoring” “2.2 Thematic maps” in which reporting more details. In Section Thematic maps, the several maps must be carefully described. Please shift “study site” as a separated section prior to Methodology.
- In section 2.1 errors of the estimates must be provided and those values should be reported also in plots involving discharges. Also instrumental errors must be added and reasons on why you selected the portable flow meter method instead of other. Please check Tazioli (2011) and more recent literature.
- 3 of the 4 section (namely a, c, d) are natural and some streambed dispersions may occur. This point should be discussed.
- please improve Conclusion section
Tazioli, A. (2011). Experimental methods for river discharge measurements: comparison among tracers and current meter. Hydrological Sciences Journal, 56(7), 1314-1324.
Author Response
Please see the attached response file
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have properly addressed the reviewer comments.
Reviewer 2 Report
Authors have adequately adressed to all the comments made after the first round of review.
