Integrated Surface-Groundwater Modelling of Nitrate Concentration in Mediterranean Rivers, the Júcar River Basin District, Spain
, Miguel Ángel Pérez-Martín 1 and Harold Tafur Hermann 2
Round 1
Reviewer 1 Report
Comments to the Article “Integrated surface-groundwater modelling of nitrate concentration in Mediterranean rivers, the Júcar River Basin District, Spain”, by D. Dorado-Guerra et al.
The authors in this article addressed the importance of estimation of river-aquifer interactions on nitrate status in surface waters.
The article contains expected components (Introduction, Methods, Results and Discussion, Conclusion). The literature review is well-organized. The paper is well-written and organized. The images are clear and communicative. The Materials and Methods section, as well as the Results and Discussion section, are exhaustive and illustrative.
Methodological concepts used in the analysis are well introduced and their importance to answer the research questions are clearly justified.
The comparison of findings with results from other studies is mentioned
Areas of further investigation are also mentioned.
One minor change/clarification is suggested to the authors:
- The legend in Figure 5-c, page 11, concerning the range of Nitrate GW, mentions “High” when NO3 concentration is over mg/L, and “Medium” also when NO3 concentration is over mg/L. Is this correct, or should be “High” when “>50”?
Author Response
R1.1: The authors in this article addressed the importance of estimation of river-aquifer interactions on nitrate status in surface waters. The article contains expected components (Introduction, Methods, Results and Discussion, Conclusion). The literature review is well-organized. The paper is well-written and organized. The images are clear and communicative. The Materials and Methods section, as well as the Results and Discussion section, are exhaustive and illustrative. Methodological concepts used in the analysis are well introduced and their importance to answer the research questions are clearly justified. The comparison of findings with results from other studies is mentioned. Areas of further investigation are also mentioned.
We thank the reviewer for this comment.
R1.2: One minor change/clarification is suggested to the authors: The legend in Figure 5-c, page 11, concerning the range of Nitrate GW, mentions “High” when NO3 concentration is over 25 mg/L, and “Medium” also when NO3 concentration is over 25 mg/L. Is this correct, or should be “High” when “>50”?
It should be “>50”. The typo has been corrected in the revised version of the manuscript.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript is an important contribution to understanding the causes of changes in water quality in rivers under the influence of natural and anthropogenic factors. For this purpose, the possibility of using two models of hydrological and water quality simulation was analyzed.
Notes on the manuscript are below.
- In the summary, it is worth referring to the conclusions obtained. There is no information as to whether the model is suitable for forecasting nitrate concentration in waters
- In the Introduction chapter, there is no information about the purpose of the modeling process. Is it only for the purpose of monitoring and identification of pollution sources or in order to take measures to prevent water degradation? What benefits can be obtained after using the analyzed models.
- The Results and discussion chapter looks more like a water quality report rather than a scientific analysis of the results obtained. The discussion of the results is weak and should be supplemented by trying to interpret the obtained data in detail.
- Conclusions are too general and too broad, they should be shortened. The chapter does not state whether the analyzed models can be used to model the concentration of nitrates in surface and groundwater.
Author Response
R2.1: The manuscript is an important contribution to understanding the causes of changes in water quality in rivers under the influence of natural and anthropogenic factors. For this purpose, the possibility of using two models of hydrological and water quality simulation was analyzed.
We thank the reviewer for this comment.
R2.2: In the summary, it is worth referring to the conclusions obtained. There is no information as to whether the model is suitable for forecasting nitrate concentration in waters.
Following the suggestion of the reviewer, a sentence has been added in the revised version of the abstract to highlight some of the applications of the models based on the conclusions of this work (lines 24-27 of marked manuscript).
R2.3: In the Introduction chapter, there is no information about the purpose of the modeling process. Is it only for the purpose of monitoring and identification of pollution sources or in order to take measures to prevent water degradation? What benefits can be obtained after using the analyzed models
Following the suggestions of the reviewer, the purposes of the modelling process and the benefits that can be obtained of the analyzed models have been detailed in the revised version of the manuscript (lines 93-95 of marked manuscript).
R2.4: The Results and discussion chapter looks more like a water quality report rather than a scientific analysis of the results obtained. The discussion of the results is weak and should be supplemented by trying to interpret the obtained data in detail.
Based on the comment of the reviewer, the results and discussion section has been extensively modified in the revised version of the manuscript (lines 263-543 of marked manuscript).
R2.5: Conclusions are too general and too broad, they should be shortened. The chapter does not state whether the analyzed models can be used to model the concentration of nitrates in surface and groundwater.
Following the suggestions of the reviewer, the conclusions section has been shortened and modified (lines 544-586 of marked manuscript), including a new sentence to highlight that the models can be used to model the concentration of nitrates in surface and groundwater (lines 577-579 of marked manuscript).
Author Response File: Author Response.pdf
Reviewer 3 Report
It is of interest to combine modelling of two different water quality models to obtain a more accurate simulation of the NO3 pollution.
Please explain what you mean as "contingency table for dichotomous event" and why you use it.
How you justify the threshold value assigned (25 mg/L)-
For the calibration , please justify and validate the processes taken into account . Which is the statistical error allowed?
How you evaluate if the performance is satisfactory or not?
How many data are measured and how many estimated. which is the desired equilibrium?
Author Response
R3.1: It is of interest to combine modelling of two different water quality models to obtain a more accurate simulation of the NO3 pollution.
We thank the reviewer for this comment.
R3.2: Please explain what you mean as "contingency table for dichotomous event" and why you use it.
Following the suggestion of the reviewer, an explanation of the contingency table for dichotomous event has been included in the revised version of the manuscript (lines 235-236 of marked manuscript).
R3.3: How you justify the threshold value assigned (25 mg/L).
This is the threshold value according to the criteria established in the Spanish water planning regulations.
R3.4: For the calibration, please justify and validate the processes taken into account . Which is the statistical error allowed? How you evaluate if the performance is satisfactory or not? How many data are measured and how many estimated. which is the desired equilibrium?
The performance of the calibration is evaluated based on the values of three indicators: relative bias (PBIAS), Nash-Sutcliffe efficiency (NSE) and Modified Kling-Gupta Efficiency (KGEM). The values of these parameters obtained for each water resource system are shown in Figure 3. The number of data measured and estimated are equal, which is a mandatory equilibrium for a proper comparison, calibration, and validation.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors responded to all comments in Review 1. After the reflections and supplementation of the manuscript, I believe that the form as it stands is suitable for publication in the Sustainability journal.
