Assessment of the Pressure Level over Lentic Waterbodies through the Estimation of Land Uses in the Catchment and Hydro-Morphological Alterations: The LUPLES Method
Round 1
Reviewer 1 Report
The manuscript covers a generally interesting topic, the estimation of the pressures by identifying the land uses in the catchment area of a watebody using a novel method named LUPLES. The manuscript needs to thoroughly revise before its publication.
General comments
(1) The English of the manuscript has to be improved. As a non-native speaker of English myself, I understand the difficulties associated with this. Many sentences are very difficult or impossible to understand and are often written in too colloquial and informal language. Many sentences remain vague and imprecise, partly due to the quality of the English. The manuscript needs to be thoroughly checked by a native speaker.
(2) In Material and Methods, it is not explained why you use linear regression and pearson correlation. Additionally, in the results, it is not explained the regression analyses and their p-values are missing.
I have provided more specific comments in the attached pdf file
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 1 Comments
(1) The English of the manuscript has to be improved. As a non-native speaker of English myself, I understand the difficulties associated with this. Many sentences are very difficult or impossible to understand and are often written in too colloquial and informal language. Many sentences remain vague and imprecise, partly due to the quality of the English. The manuscript needs to be thoroughly checked by a native speaker.
English has been reviewed.
(2) In Material and Methods, it is not explained why you use linear regression and pearson correlation. Additionally, in the results, it is not explained the regression analyses and their p-values are missing.
The explanation of the statistical analyses is given in lines 340-349. Now, the regressions, with their p-values, are included in Tables 4 and 5, and explained in more detail in the results section.
I have provided more specific comments in the attached pdf file
Comments on the pdf attached.
All the minor mistakes marked in the pdf, such as commas, suggestions for words modifications, suppression or changes of words or expressions, etc. have been accomplished as suggested by the reviewer.
TITLE: I think that you should shorten the title.
The title has been reduced as suggested trying to be more direct: “Assessment of the pressure level over lentic waterbodies through the estimation of land uses in the catchment and hydro-morphological alterations in the watershed: The LUPLES method”
KEYWORD OVERLAP WITH THE TITLE: It is better not to use the same words as in the title.
Some keywords have been removed or changed, trying not to repeat the words used in the title: “GIS analysis; Mediterranean coastal lagoons; water pollution; ecological status; Water Framework Directive; catchment areas”
L42: Please rephrase this sentence in a clearer way
The sentence has been modified to “The ecological quality of lentic ecosystems is largely influenced by their catchments, as runoff ends in the waterbody and largely determines its characteristics [4]. “, now in line 41-43
L47-49: Please rephrase this sentence in a clearer way.
The sentence has been modified to “Both the estimation of direct impacts on hydrological and morphological features, as well as that of the indirect impacts based on the quantification of land uses causing alterations in the water and sediments quality, provide a useful approach to assess the relationship between the waterbody and its environment [11, 12]. ” now in Line 47-50
L57-59: Please rephrase this sentence in a clearer way
The sentence has been modified to “Physical, chemical, biological, hydrological and morphological features of lentic ecosystems can change as a consequence of the impact caused by the rising of pressures promoted by land uses and direct alterations.“ now in line 57-59
L67: (for GIS) The first time you use an abbreviation in the text, present both the spelled-out version and the short form.
The description of the abbreviation GIS has been included the first time it appears, now in line 67
L76-79: Please rephrase this sentence in a clearer way.
The sentence has been changed to “The correlation of the response of the ecological status metrics with the pressures level estimated from land uses and the determination of hydro-morphological alterations may provide insights on how waterbodies respond to the pressure levels, and might be extrapolated for waterbodies not well covered by the monitoring networks providing a direct ecological status assessment [33]. ” now in lines 77-80
L119-121: Please rephrase this sentence in a clearer way
The sentence has been shortened to “Hydrological and morphological pressures were assessed in a set of 43 waterbodies of different types of with available information on specific metrics based on macrophytes [36] (Table S1). ” now in lines 122-123
L125: Add reference for the orthophotos
The high resolution orthophotos used were obtained from Google Earth Pro as base layers of the portal. An explanation to the references added on the supplementary material is included in line 126: “References of the dates of the images used are in Table S1.”
TABLE 1 caption: Please rephrase
The caption of the table has been rephrased to: “Location, morphological features, water electrical conductivity (Cond.) and classification according to salinity, and degree of affection of the sites studied for the determination of the pollution pressures. Conductivity is shown as the average ± standard deviation, as well as the maximum and minimum values (range) given by the data sources. HMWB = Heavily modified water body” now in line 132
TABLE 1: (for desvest): what is the meaning of this parameter?
Standard deviation. It is now included in the column of the variable (mean ± s.d.), then explained in the table caption with the correct name.
FIGURE 2 words d) e) f):
The naming of the panels of the figure are now corrected.
L150-153: Please rephrase this sentence in a clearer way
The sentence has been modified to: “The lagoons BIGU, ITTI, THAU and NARB, presented more than one independent catchment area, e.g. north-south, according to the determination made by the GIS processes .” now in lines 159-160
L194: Why these uses were not considered as pressures? Please, explain the reasons.
A sentence has been added to explain why natural uses are not considered as pressures in the pressures assessment: “Natural uses were not considered for the pressures assessment due to their low impact regarding the pressures identified in comparison with the other land uses promoted by the human activities.” now in lines 203-204
L202: How do you weighted these factors? By expert judgment or literature? Please explain these weights.
We first ranked every land use as causing low (0-0.2) moderate (0.3-0.6) or high (0.7-0.9) impact in all the pressures considered. The classification into these defined ranks and their refining to a specific weighted factor was defined according to the literature, mainly based on European reports on pressure estimation on waterbodies and the level of its specific impacts, as well as on specific scientific literature, such as reviews and papers quantifying the impact of the different land uses over the pressures’ types considered. Now the procedure is better explained in lines 209-219: “Once normalized the areas of each land use type, the relative contribution of each land use type to the level of each specific pressure related to pollution (eutrophication, organic enrichment, acidification and specific pollutants) was obtained for each of the studied coastal lagoons by using a weighting factor. Weighting factors were adjusted according to the relative influence of each land use on each defined pressure type, the later causing impacts on the waterbody. The weighting factor was assigned by ranking each land use over a range from 0 to 1, as low (0.0 to 0.2),/ middle (0.3 to 0.6) and high (0.7 to 1). The determination of the degree of contribution (specific weighting factor) of each land use to each pressure type was then fixed within these ranges based on the literature, mainly using technical reports on pressure evaluations and their impacts in lentic waterbodies [43], as well as scientific papers and monographies on the impact of the land uses causing the increase of the assessed pressures (e.g. [45-47] for eutrophication, [48] for organic enrichment, [49, 50] for acidification, and[51-53] for pollutants).” This is additionally explained in lines 229-253.
L246: Are the studied lagoons natural or heavily modified? Please indicate this information in Table 1.
A column has been added to Table 1 giving this information. Note that for waterbodies from Italy and Greece we did not find this information. For the waterbodies used in the hydro-morphological pressures, a column has also been added to Table S1 with this information.
L248: Where are located these studied sites in accordance with the lagoons of Table 1?
Study sites for the hydro-morphological pressures assessment were located in Spain, using the DATAGUA database information, and the metric values available from Spanish River Basin Authorities, as such information was not available for the coastal lagoons studied for pollution related pressures. Their coordinates are given in Table S1.
L297: Add the references
References are listed in the supplementary material, and include several reports and information webs from the River Basin Authorities from Spain and France This has now been described in line 298: “The data sources and the availability of values for these variables in the studied lagoons are shown in Tables S2 and S3. .”
L 298: Please explain why you choose this analysis with more details
The application of Linear models is explained in lines 346-349: “Linear regression models were also obtained for determining the response of the metric values to the pressure levels. Linear regressions were selected following the recommendations of the WFD when studying the relationship between pressures and the assessed ecological status.”
L300: Please explain with more details why you apply this analysis
The application of the Pearson coefficient is explained in lines 342-346: “For hydrological and morphological pressures, Pearson correlation coefficients were applied, as both studied variables (metric values and pressures levels) were continuous and fitted on a normal distribution. In this case, each waterbody had a pressure level and a metric value, in contrast with the land use pressures, where each waterbody had a single pressure level per pressure type with multiple metric values .”
L302: Add a title for this chapter.
We added a title to his section has been named as: “3.1. Estimation of pressures in coastal lagoons”, now in line 352.
L 303-304: Please rephrase
Sentence has been rephrased as: “For the selected Mediterranean coastal lagoons , the relative coverage of the main groups of land uses in the catchment areas differed among sites (Figure 4), with a larger area of rainfed agriculture in most catchments.” Now in lines 353-355.
FIGURE 4: Add the percentages in the figure
The percentage from each land use in all the studied lagoons is already added to the figure.
TABLE 3: In my opinion, you can present the categorization of these levels with different colors and mentioned them in the table. For instance low pressure level with green, moderate pressure level with yellow, high pressure level with orange and very high pressure level with red.
Categorization of pressure levels are indicated and shown in the table as suggested.
TABLE 4: It is not necessary to explain them in the legend.
The list of the physical, chemical, and biological variables included in the statistics are removed from the table caption.
TABLE 4: Keep three digits (in the R2)
R2 values now give three digits as suggested.
TABLE 4: Add the p-value from the linear regression, because in some cases the R2 values are low.
P-values and statistic F obtained from the linear regression analysis are now included in the Table.
All p-value > 0.001 in italics
All p-values are now in italics.
L 374-375: Please rephrase his sentence in a clearer way
The sentence has been rephrased as: “Finally, even with a low number of samples (n), a negative correlation was found with the benthic invertebrates EQR, demonstrating the negative response of this ecological quality indicator to eutrophication (Figure 5.d).” Now in lines 430-432.
FIGURES 5, 6, 7, 8: In this figure you illustrated the relationship between eutrophication pressure level with some parameters, apart from Spearman correlation. Please explain clearly in the -figure caption. Add the p-value from the regression analyses.
Both correlation and regression model with their significant levels are now explained in the figure captions, and included properly in the figures.
TABLE 5: Keep three digits (in the R2)
R2 values now give three digits as suggested.
TABLE 5: Add the p-value from the regression analysis.
P-values and statistic F obtained from the linear regression are included in the Table.
L 462-463: … d the relationship between eutrophication press
The sentence has been completed: “…which validates the method developed.” now in line 547.
Reviewer 2 Report
Morant et al. present in their article a new method to assess the amount of integrated pressures occurring in Mediterranean coastal lagoons based on fine analyses of land uses through GIS techniques. They correlated the outputs obtained with GES descriptors monitored in these ecosystems.
If the method presented seems to be seriously developed, quite efficient and interesting to assess pressures. The paper suffers from an often imprecise writing, and questionable data treatments and use of statistics. Moreover, the presented objective of assessing ecological status through pressures quantification is highly speculative, and therefore the title of the article is misleading.
Please find below my main comments and suggestions:
L19 : Here you use the term lake which is quite different from the term lagoon used in the title. As well, this term coastal lagoon is currently never used in the abstract nor the introduction. Please clarify the terminology and make it homogenized in the article.
L57-60: This is a very difficult sentence to read. Please rephrase in maybe splitting into two sentences.
L106-108: Please rewrite
Table1:
-It would have been useful for the reader to indicate, the size of the considered lagoons and the size of the catchment areas calculated.
-What is the meaning of “desvest” in the first line of the 7th column? I guess it stands for standard deviation. Please change
Figure 1:
-Please add in the figure legend that the yellow color corresponds to the Mediterranean biogeographical region (this is my guess, is that true?)
Figure2:
-Please specify the spatial scale of these maps
-there is no panel (d) although mentioned in the legend, and no (g) in the legend. Please change.
L205 and Table 2: Is there a rational basis (literature, quantitative case studies, expert opinion) for the establishment of this weighting. As it currently stands, it reads as it literally pops up as evidence, but without any justification. This is very important because these have a major influence on your index calculations.
L275-279: you should give (can be as an appendix) what data were available in the different lagoons
L282: can you give to the reader what biotic indices have been used for benthic fauna EQR? Were they similar across countries? Already based on sensitivity of taxa to organic enrichment (which could lead to a certain degree of circularity in the interpretation of your results)?
Figure 4: Please indicate the main category of the lagoons (freshwater, brackish, saline) in the figure
L329: the highest
Results, figures 5, 6, 7:
-Why is there so much points? Are they obtained from all replicates? at different sampling occasions? It is very hard to understand what is the data and its meaning in these graphs.
-Please also add the number of lagoon considered in each graph
-Please also specify (maybe by using different colors) the main type of the lagoons in the graphs.
-Along the same line, I wonder if it is actually ecologically pertinent and coherent to get on the same graphs fresh, brackish and saline lagoon. At least this choice is to be justified in the text.
-Although significant, most of these correlations must be considered as weak with (very) small amount of variance explained and then a high degree of uncertainty associated. This is never stated. Please adjust in the text.
-Please always use the same scale of the x axis.
Ok, now I see the discussion paragraph l514-530 dealing with the weak correlations and the structuration of data. These definitely have to be highlighted before in the article (mat met, results).
-Why have you chosen to include all these datapoints (from 2004) and not only those corresponding to your pressure assessment? it does not necessarily make sense to me
-As well, have you tried to establish these relationships lagoon type wise? Could the relationships differ amongst types?
These two recommendations must be tackled. On the one hand it would reduce the N for the correlations and then diminish the chance of getting significant results, but in this particular case it is of interest because sharpening your results and interpretations while helping in focusing only on good relationships and not mainly on something related to noise and including all lagoon types.
L432-435: in line with my previous comment, the problem is that these relationships used through the weighting factors are not justified by (1) literature or (2) a quantitative assessment in specific case studies. Strengthening the establishment of these factors is to me of primary importance for your work.
L464: the sentence is pending, something is probably lacking?
L539-547: I would never go with this statement that your method could be used to assess ecological status. I think that the method developed seems quite efficient, useful, and very interesting in order to assess the integrated pressures acting on these coastal lagoons. However, approaching status only with pressures is highly speculative in any case. I suggest to remove these statements.
Author Response
L19 : Here you use the term lake which is quite different from the term lagoon used in the title. As well, this term coastal lagoon is currently never used in the abstract nor the introduction. Please clarify the terminology and make it homogenized in the article.
The term lake has been removed. The term lentic waterbody or lentic ecosystem has been used through the manuscript as a general way to refer to the ecosystems addressed in the paper (standing waters). When referring specifically to the sites selected for the assessment of pollution-related pressures, which has exclusively performed in coastal lagoons, then, the term coastal lagoons has been used.
L57-60: This is a very difficult sentence to read. Please rephrase in maybe splitting into two sentences.
The sentence has been modified to “Physical, chemical, biological, hydrological and morphological features of lentic ecosystems can change as a consequence of the impact caused by the rising of pressures promoted by land uses and direct alterations.“ now in lines 57-59.
L106-108: Please rewrite
The sentence has been modified to “The method developed consist on the application of two approaches to assess the pollution and the hydro-morphological pressures, respectively. A different set of study sites was used for the assay of these approaches.” now in lines 109-111.
Table1:
-It would have been useful for the reader to indicate, the size of the considered lagoons and the size of the catchment areas calculated.
Two columns indicating the size of the lagoons and the catchment areas estimated by the method described are now included in the Table 1, and explained in the Table caption.
-What is the meaning of “desvest” in the first line of the 7th column? I guess it stands for standard deviation. Please change
Yes, it means standard deviation, now included in the column of the variable as mean ± s.d., then explained in the table caption with the correct name.
Figure 1:
-Please add in the figure legend that the yellow color corresponds to the Mediterranean biogeographical region (this is my guess, is that true?)
A legend indicating the correspondence of the Mediterranean biogeographical region is now shown in the map is added.
Figure2:
-Please specify the spatial scale of these maps
Spatial scale and north arrow are now included in the figure.
-there is no panel (d) although mentioned in the legend, and no (g) in the legend. Please change.
The name of the panels of the figure are now correctly stated.
L205 and Table 2: Is there a rational basis (literature, quantitative case studies, expert opinion) for the establishment of this weighting. As it currently stands, it reads as it literally pops up as evidence, but without any justification. This is very important because these have a major influence on your index calculations.
We first ranked every land use as causing low (0-0.2) moderate (0.3-0.6) or high (0.7-0.9) impact in all the pressures considered. The classification into these defined ranks and their refining to a specific weighted factor was defined according to the literature, mainly based on European reports on pressure estimation on waterbodies and the level of its specific impacts, as well as on specific scientific literature, such as reviews and papers quantifying the impact of the different land uses over the pressures’ types considered. Now the procedure is better explained in lines 209-219: “Once normalized the areas of each land use type, the relative contribution of each land use type to the level of each specific pressure related to pollution (eutrophication, organic enrichment, acidification and specific pollutants) was obtained for each of the studied coastal lagoons by using a weighting factor. Weighting factors were adjusted according to the relative influence of each land use on each defined pressure type, the later causing impacts on the waterbody. The weighting factor was assigned by ranking each land use over a range from 0 to 1, as low (0.0 to 0.2),/ middle (0.3 to 0.6) and high (0.7 to 1). The determination of the degree of contribution (specific weighting factor) of each land use to each pressure type was then fixed within these ranges based on the literature, mainly using technical reports on pressure evaluations and their impacts in lentic waterbodies [43], as well as scientific papers and monographies on the impact of the land uses causing the increase of the assessed pressures (e.g. [45-47] for eutrophication, [48] for organic enrichment, [49, 50] for acidification, and[51-53] for pollutants).” This is additionally explained in lines 229-253.
L275-279: you should give (can be as an appendix) what data were available in the different lagoons
The supplementary Table S3 has now been included stating the variables available in the different lagoons: “The data sources and availability for these selected variables in the studied lagoons are shown in Tables S2 and S3. ” in line 298.
L282: can you give to the reader what biotic indices have been used for benthic fauna EQR? Were they similar across countries? Already based on sensitivity of taxa to organic enrichment (which could lead to a certain degree of circularity in the interpretation of your results)?
An explanation of the macrophyte and benthic fauna indices has been included in lines 307-318: “Macrophytes BQE assessment for both Member States is mainly based on the percentage of vegetation cover, the relative percentage of type-specific taxa, and the specific richness. Indices used for the benthic fauna in France were AMBI (AZTI Marine Biotic Index) and M-AMBI. AMBI is based on the relative abundance of the species of the benthic macrofauna classified in ecological groups, which represent different degrees of tolerance to the alteration of the environment. AMBI correlates with an anthropogenic index, in this case the % of organic matter in sediments (as indicated in the national reports included in Table S2). M-AMBI is obtained by factor analysis, from the AMBI, the specific richness S and the diversity index H′. In Spain, the standardized benthic invertebrates index used for lentic waterbodies is the IBCAEL, that joins two indices assessing the taxonomic composition and the abundance of the benthic invertebrates assemblages. This index was also demonstrated to be a good indicator of the ecological quality of lentic waterbodies [44].”
Figure 4: Please indicate the main category of the lagoons (freshwater, brackish, saline) in the figure
The category of the lagoons is now indicated in the figure.
L329: the highest
Changed.
Results, figures 5, 6, 7:
-Why is there so much points? Are they obtained from all replicates? at different sampling occasions? It is very hard to understand what is the data and its meaning in these graphs.
The selection of the sites, all of them coastal lagoons, was limited by the availability information on metrics on the European and River Basin Authorities databases, as explained in lines 115-121.
The idea of this study was to define and implement, as well as to validate, a method based on the use of public free data (both for the SIG part and for the validation with WFD metrics). We now have explained the nature and source of the data and the interpretation of the results also in the Methods section (lines 323-325); “Each pressure level assessed corresponding to every study site was correlated with the available physical-chemical and biological disaggregated metric data. Since both replicates and data from different dates were considered, this increased the variability.” This has also been briefly explained in the results section as “Although linear regressions were significant, (p-values < 0.05), a small amount of variance was explained in several cases, what could be due to the nature of the data. Each pressure level assigned in the study sites was correlated with all the available values of each metric. Therefore, the results showed for each x value (pressure level) a vertical distribution of points through the X axis corresponding to the individual data for each associated sampling site at different dates, as found in the European and River Basin Authorities databases.” (lines 409-415). The discussion has also been changed to afford these issues (lines 600-619).
-Please also add the number of lagoon considered in each graph
The number of lagoons and the sampling points are added to the figures information (considering for different sampling points within the same lagoon that in some cases considered separated catchments, as explained in the ms.)
-Please also specify (maybe by using different colors) the main type of the lagoons in the graphs.
We tried to do it, but because colors were widely used within the manuscript, to avoid confusions we did it just by adding the lagoon type on the text when possible,
-Along the same line, I wonder if it is actually ecologically pertinent and coherent to get on the same graphs fresh, brackish and saline lagoon. At least this choice is to be justified in the text.
Such kind of analyses is not affordable at this stage because of the poor availability of data from public sources. In fact, we tested the method in the different groups (fresh, brackish and saline), but the much lower pressure range impeded a proper statistical analysis for separated groups in most cases, though for those were enough data were available the trends were similar to those shown when jointly considering all studied sites. For the method validation, a large-enough range of pressures is needed to correlate and obtain linear regressions that show the responses of the metrics to the pressures with significant trends. By using only one of these ecological types, there was not commonly enough pressure range to get these large pressure ranges (e.g., saline lagoons, COMA, NARB, THAU and URBI, have generally all low-moderate pressure in the four types studied, meanwhile with only two freshwater systems ALBU and GELA, with moderate-high pressures, correlation could not be done). We also tested the pressures levels correlations as a dependent variable of conductivity, in order to see whether freshwater, brackish and saline waters could behave different in their affection by the pressures’ levels , but not any significant result was found, neither by comparison of means by ANOVAs. We thus assumed that the conductivity had a minor role in relation to the affection by the pressures assessed.
Now this is explained in Line 328-334: “When testing the method, all the studied waterbodies were used without splitting in groups by its salinity (conductivity) levels: This is because a wide range of pressures is required to evaluate and determine significant trends in the response of the ecological status metrics to the pressures, which cannot be achieved when splitting by types because the sample would be too small, although some assays on that sense showed similar trends for cases with enough sample size (data not shown). Further work will be developed in the future for that purpose.”
-Although significant, most of these correlations must be considered as weak with (very) small amount of variance explained and then a high degree of uncertainty associated. This is never stated. Please adjust in the text.
We included a more detailed interpretation of the results in the manuscript, addressing this issue, e.g. line 410-415: “Although linear regressions were significant, (p-values < 0.05), a small amount of variance was explained in several cases, what could be due to the nature of the data. Each pressure level assigned in the study sites was correlated with all the available values of each metric. Therefore, the results showed for each x value (pressure level) a vertical distribution of points through the X axis corresponding to the individual data for each associated sampling site at different dates, as found in the European and River Basin Authorities databases.”
-Please always use the same scale of the x axis.
Same x axis have now been used for each of the pressure type figures, as indicated. For different pressure types (e.g. hydrological and morphological, we preferred not to use same x scale axis, as the pressures estimated and used for the analysis range differently.
Ok, now I see the discussion paragraph l514-530 dealing with the weak correlations and the structuration of data. These definitely have to be highlighted before in the article (mat met, results).
We have highlighted the structuration of data in the methods and results sections, as explained in a previous comment, this being indicated in methods (lines 323-325) and results (lines 409-415).
-Why have you chosen to include all these datapoints (from 2004) and not only those corresponding to your pressure assessment? it does not necessarily make sense to me
Data was more abundant around 2012, when there was a Corine-Land Cover map available that we used. However, there was not enough data to explore the results by using only data from one or few years. In fact, some parameters like the Secchi disk, that would have been interesting to explore, had only data on four sites during the historical data series. We tried every option, and using only data from two-three years also gave significant correlations and trends for some of the parameters studied, but with a great variation and low variance explained compared to the complete studied period (2004-2013). However, there were other parameters without a response shown when using just data from a shorter period of time because of the lack of data for several study sites. Anyhow, it should be considered that the land uses reflected in the CORINE 2012 release integrate data collected in the previous years, in such a way that using data from ecological status collected some years prior to this date was actually time-coherent
-As well, have you tried to establish these relationships lagoon type wise? Could the relationships differ amongst types? These two recommendations must be tackled. On the one hand it would reduce the N for the correlations and then diminish the chance of getting significant results, but in this particular case it is of interest because sharpening your results and interpretations while helping in focusing only on good relationships and not mainly on something related to noise and including all lagoon types.
As indicated in the response above, we analysed the relationships per lagoon type and reducing the period of sampling data. For the first case, there was not enough data for a proper analysis when studying per subtype according to the salinity, due to the need of a large-enough range of pressures to define the response of the metric values to these pressures. When reducing the years of data for the analysis, not only the sample size (N) was reduced, but also the number of waterbodies with data, as not everyone had data all the years, so regressions could not be properly done.
On the other hand, it must be considered that this paper presents, assays, and validate this new method, but our purpose is to refine it by performing further studies that would include not only the consideration of more sites per each type of lenitic ecosystem, but also other types, as well as additional approaches to refine the method (e.g. applying genetic programming to refine the weighting factors).
L432-435: in line with my previous comment, the problem is that these relationships used through the weighting factors are not justified by (1) literature or (2) a quantitative assessment in specific case studies. Strengthening the establishment of these factors is to me of primary importance for your work.
See previous responses
L464: the sentence is pending, something is probably lacking?
The sentence has been completed: “…which validates the method developed.” Now in line 547.
L539-547: I would never go with this statement that your method could be used to assess ecological status. I think that the method developed seems quite efficient, useful, and very interesting in order to assess the integrated pressures acting on these coastal lagoons. However, approaching status only with pressures is highly speculative in any case. I suggest to remove these statements.
We have changed the focus on the usefulness of the method for the evaluation of the ecological status. We showed the application of the method as an approach to assess the pressure levels, rather than its use for a direct determination of the ecological status at a general level. We have removed the overestimation of the method capacity elsewhere in the manuscript, starting at the title: on the title, “Assessment of the pressure level over lentic waterbodies through the estimation of land uses in the catchment and hydro-morphological alterations: The LUPLES method” and in the following sections:
Abstract: line 33: ‘…and could be applied to make a first approximation on their ecological status’
Introduction: lines 73-75: ‘The use of a pressure estimation methodology based on land uses may be applied to used as afirst general approach preliminary assessmentapproach ofto the forecasting of the ecological status assessment of waterbodies, while used forespecially for those not included in monitoring networks”.
Objective: lines 103-106: ‘The here defined method for the pressures assessment could be used as complementary for identifying in an indirect way an approach to the ecological status of waterbodies, as well as for the estimation of pressures in non-surveyed aquatic ecosystems driving its ecological status.’
Discussion: lines 634-636: “Faster and cheaper methods, such as that here proposed, may help to approach the assessment of the pressures as an indirect way to identify their ecological status when monitoring facilities are not available.”
Considering these changes, we have maintained that related to the fact that we have demonstrated in our results the significant correlations among the pressure levels determined by the new LUPLES method for pressure level determination and the indicators of the ecological status used by the European Member States.
Reviewer 3 Report
The paper presents a valid methodological approach that allows quantifying 22 pressures on water masses caused by land uses, which allow predicting impacts on their ecological status.
The results show statistically significant correlations between the pressure levels quantified by the LUPLES method and ecological indicators based on biological, physical and chemical metrics.
It is a very useful methodology that helps to estimate the pressures to which water masses are subjected and that allow predicting their ecological status.
It is undoubtedly an excellent methodological proposal. It is well written and well founded so I do not see anything to prevent its publication as it has been presented.
Very goog work. Congratulations.
Author Response
There are no comments to respond to this review. We thank you for your time reviewing this manuscript
Round 2
Reviewer 1 Report
Dear Authors, thanks for submitting the revised version of the paper. I've seen you take into consideration all points raised and I'm satisfied with the corrections.
Reviewer 2 Report
I think that the changes made to the manuscript comparing to the first submitted version clearly improve the clarity and the soundness of this study. As well, the responses the authors gave to my comments were fully satisfactory. I would therefore recommend this paper for publication.
