the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 25 Jan 2021
Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area
Abstract. Deforestation for farming and grazing purposes has become a global challenge. To study the impact of deforestation on soil erosion rates and soil physicochemical properties, Zarivar Lake watershed, Kurdestan Province, Iran, was selected. Converting the steep hillslopes naturally under oak forest to rainfed vineyards has been one of the most common land-use changes in the area. We used 137Cs and 210Pbex radionuclides and quantified the Chernobyl-derived 137Cs fallout with 239+240Pu. The soil samples were collected from two adjacent and similar hillslopes, one of which is under natural forest, while the other is under rainfed vineyard. Using 137Cs/239+240Pu rates and a simple unmixing of the 137Cs sources indicated that 50.2 ± 10.0 % of 137Cs was Chernobyl-derived. The mean reference inventory values of 137Cs, 210Pbex, and 239+240Pu were estimated to be at 6152 ± 1266, 6079 ± 1511, and 135 ± 31 Bq m−2, respectively. At the forested hillslope, net soil erosion rates based on 137Cs, and 210Pbex, techniques were estimated to be at 5.0 and 5.9 Mg ha−1 yr−1, respectively, resulting in Sediment Delivery Ratios (SDRs) of 96 and 70 %. However, at the vineyard hillslope, the net soil redistribution rates were at 25.9 and 32.5 Mg ha−1 yr−1 for 137Cs and 210Pbex, respectively, resulting in respective SDRs of around 95 and 92 %. Both 137Cs and 210Pbex indicated that as a result of deforestation, soil erosion has increased by approximately five times. Percolation Stabilities (PS) in forest and vineyard topsoil are about 309 and 160 gr H2O 600 s−1 classified as rapid and moderate PSs, respectively. Rapid PS in forest soil implies high aggregate stability, whereas moderate PS in vineyard soils indicates that they are generally weakly-structured. All in all, the results of the present study revealed that deforestation and converting natural vegetation to cropland prompted soil loss and deteriorated physicochemical properties of the soil.
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RC1: 'Comment on soil-2021-2', Anonymous Referee #1, 08 Feb 2021
General comments
The manuscript is based on the results of assessing the erosion/deposition rates using FRN as markers. The following questions arise when reading the manuscript:
1/ Based on Figure 4, we can conclude that the variability of 137Cs on a forested slope is higher than on vineyards. This clearly indicates that the Chernobyl fallout was extremely uneven in the area. It is obvious, that the initial 137Cs spatial variability of Chernobyl fallout too high for using the 137Cs technique for evaluating the soil losses based only on one reference location. It is necessary to evaluate 137Cs initial inventory minimum at three reference locations for the evaluation of the trend of initial fallout (See: Handbook for the Assessment of Soil Erosion and Sedimentation Using Environmental Radionuclides, F.Zapata for details). So authors aren't able to confirm the correctness of their evaluation of soil losses, based on Chernobyl-derived 137Cs because they have only one reference location on the distance of about 1 km from the studied site.
2/ On the other hand, if the mean 210Pb inventories values ââare approximately the same for the forested slope and vineyard (see bottom of page 9: 210Pbex inventories at 4068.3±2345.8 and 3990.1±2892.2 Bq m-2, respectively for forested and vineyard hillslopes) , then it is completely incomprehensible how such a large difference in net erosion rates (calculated based on 210Pbex) between the forested area and the vineyards was received (see Table 2). It is quite obvious that this is a very gross error in the calculations.
3/ The local spatial variation of the 137Cs fallout, as well as the other radionuclides, is >20% on the reference location. Isn't recommended to use FRD for evaluation of soil loss/gain in areas where initial fallout variability > 20% due to very high uncertainty of the results (see papers written by D. Walling and the other experts in the application of FRN for the evaluation of soil redistribution rates).
4/ Authors indicate that …The soil redistribution rates were, therefore, estimated using the Diffusion and Migration Model 185 (DMM) (Walling et al., 2002, 2014) in forested hillslope, Mass Balance Model II (MBM II) (Walling et al., 2002, 2014) in cultivated hillslope, and Modelling Deposition and Erosion rates with RadioNuclides (MODERN; Arata et al., 2016a, 2016b) – It is necessary to present the equations for all conversion models and to explain how you determine the parameters for each model.
5/ In addition application FRN for evaluation soil erosion rates in the forest isn't possible at all due to the influence of the crown of trees on the initial spatial variability.
Specific comments
1/ Are you sure that sampling only 40 cm layer is enough for determination of FRN total inventory in deposition location? How you can confirm that?
2/ In the Supplementary Material, the 137Cs depth distribution in the lake is presented. But it is completely incomprehensible how it was obtained?
3/ Figure 5 – how do you construct both maps with so high spatial resolution? Why was the total precipitation in April and May used to construct these maps? The accident at the Chernobyl nuclear power plant occurred on April 26 and the bulk of the Chernobyl fallout was observed until May 15 and was associated with the fallout of only one rain at a distance from Chernobyl.
4/ In the references, there are practically no papers on the use of 137 for assessing the erosion/sedimentation rates, prepared on the basis of research in the Chernobyl-affected areas (the UK, Poland, Belarus, Russia, Ukraine, Scandinavia, the Baltic States)
5/ It is not specified anywhere in the ms when the forest was cut down and vineyards were planted on the studied site.
Technical corrections:
1/ Introduction … than five times, increasing from 2.6 million ha (Wilber, 1948) to 18.5 million ha – should be more than seven times
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AC1: 'Reply on RC1', Maral Khodadadi, 05 Apr 2021
Dear Reviewer#1,
We would like to thank you for the helpful comments on our manuscript entitled “Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area”. Indeed, these valuable comments helped us to improve the content of our study.
We carefully considered the comments and revised our manuscript accordingly. Please find below our detailed responses.
Yours sincerely,
Maral Khodadadi on behalf of all the authors.
-
AC1: 'Reply on RC1', Maral Khodadadi, 05 Apr 2021
-
RC2: 'Comment on soil-2021-2', Anonymous Referee #2, 11 Feb 2021
General comments
Overall, the study focuses on a relevant topic and presents interesting results and is therefore definitely worth publishing after some modifications and improvements to the current manuscript have been made. This manuscript represents valuable results, and a good approximation to better understand the differences and similarities between different methods to calculate soil redistribution rates and its relationship with some physical properties and soil nutrients.
The study includes interesting findings first reported in these areas of Iran and fits within SOIL scopes. However, in its current state, I think it requires quite a bit more work in terms of rearranging and editing before it is ready for publication. Overall, the study focuses on a relevant topic and presents interesting, results and is therefore worth publishing after some major modifications and improvements to the current manuscript have been made.
First, I think authors should clarify some of the previous reviewer questions. To avoid some repetition, I have been more focused on specific details. Apart from the general comments about each section, I have included some comments about the figures (14) and the text (17). An additional major issue I see in this manuscript is the enormous number of references included. If I am not wrong, there are more than 100 references. I think it is more than needed for a novel study.
Introduction
I think you need to emphasise this work's aims at the end of this section, the authors present an interesting study, but sometimes it is easy to get confused because the aim of the manuscript is repeated trough the introduction section. Thus, it could be useful to be more specific at the end of this section and reorder or rewrite some parts of the introduction.
Results and discussion
In this section, I would encourage the authors to synthesise the results and focus only on the results. Sometimes it seems that the discussion is a little bit mixed with the results.
Furthermore, I think more than 2800 words for the discussion section is excessive. In this section, authors tend to repeat most of the results, and there is an excessive number of comparisons with other studies. I think the manuscript could be reduced here. This statement is quite clear because authors have included more than 100 references, what it is just disproportionate. Don't you think? For example, 50-60 references are considered a high number of references, still acceptable but high.
Conclusions
I think that the text could be improved here (to avoid restricting it to a repetition of what was written before). The first 6 lines did not include a conclusion and just repeated previous parts of the manuscript. After a very rapid summary of the main results, you could stress the potential novel avenues for research in the future.
497 you could specify the location without using brackets, please rewrite the sentence.
496-500 Following table 1, the study pursued in Golestan Province with similar mean annual precipitation (MAP), showed significantly lower values than your study. Do authors think that all the difference could be due to the location even if both are located in the northern part of Iran?
Figures
Fig. 1 Subcatchment names are blurred and mixed with the division lines. I think you could create a different type of labels such as pin flags, for example.
The scale could be smaller, and a black-white style could fit better.
Instead of displaying the lake on the magnified Kurdistan province map, you could display the catchment limits.
Streams or rivers. These terms are pretty much interchangeable, but according to your scale, you have a stream with a length of 2000Km.
It will definitely help to visualise your study if you could include some pictures of the forest and vineyards.
Fig. 2 At least in my figure, the legend does not fit with the symbols. Furthermore, it is quite difficult to discern the separation between points. When plotting in Surfer (I think you used this software) the colours suffer a small colour change. Please try to modify your legend accordingly.
Is it true that your stream/river ends before reaching the outlet?
The height axis was not specified, and the meters cannot be seeing. If it is difficult to modify this in the software used, you could try to modify it by using additional graphical software.
The colour legend about the height is not specified. However, it would be nice to see the land use map over the DEM. It can be done in Surfer.
Fig. 5 I think you should use the same colour scale for both maps. Thus, you can easily compare them.
Fig. 6 What are the green dots? Please show it also in the legend.
Fig. 7 It is already nice, but you could improve by giving the equation the colour f the lines. However, do it carefully because maybe the green colour is too light to be correctly visualised.
Fig. 8 A little bit of colour here it would be nice.
Fig. 9 Same here, but just as a piece of advice.
Specific comments and technical corrections
Apart from the general comments, I have added some specific comments about the text and the figures. The authors might find them useful to improve their manuscript. "In my opinion", the inclusion of these points would significantly increase the audience interest of this manuscript that presents an interesting study. Here I have attached some typing error or minor suggestions to improve the text:
Line 38-39 I think this could better fit. "The transition/conversion from natural covers to cultivated lands have increased drastically."
Line 40 "more rapid than ever before" I think this is too much to state. Maybe something like this "the las century/or centuries" could do the job.
Line 55 "and the subsequent increase in soil erosion."
Line 55-56 This statement is too general. In the northern part of the Mediterranean region, especially in mountain agroecosystems, recent land-use changes produced just the inverse trend due to the land abandonment (that it is also a land use change). You could find many recent manuscripts using 137Cs and also 210Pb techniques that describe the issue, especially from Spanish an Italian catchments.
Line 63, 65, 69 just as a recommendation, I would prefer if you don't use the words "e.g." that much.
Line 98-100 These two sentences were repeated in the previous paragraph. I think you could reduce the text here and keep the MS focuses on your objectives.
Line 100 Did the authors missed a reference?
Line 104 runoff?
Line 111 "deforestation on and soil". Could it be mistyped?
Line 120 Figure two shows nothing related to 12 sub-watersheds. I think you should rewrite this paragraph to make it clearer for the readership. It is not very clear.
Line 121 It would be nice to include the data of max and min altitude here. You have graphically included in the figure, but it has not been specified.
Line 140 Besides,?
Line 143-15 A fragment could be missing. For what have they been constructed? I think it is obvious, but it would be nice to specify it; thus, making your point clearer to the readership.
Line 150 Keep the same style. Here you've used italics.
Line 247 This is an important part of the work. Thus, further description is needed.
Line 285 It would be nice to see a correlation matrix between all the properties.
Line 323 You cite a strong study about it, but you could also include the correlation of the data presented in Table 1. It will be only around 0.5 but still could support your discussion.
Citation: https://doi.org/10.5194/soil-2021-2-RC2 -
AC2: 'Reply on RC2', Maral Khodadadi, 05 Apr 2021
Dear Reviewer#2,
We would like to thank you for the helpful comments on our manuscript entitled “Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area”. Indeed, these valuable comments helped us to improve the content of our study.
We carefully considered the comments and revised our manuscript accordingly. Please find below our detailed responses.
Yours sincerely,
Maral Khodadadi on behalf of all the authors.
-
AC2: 'Reply on RC2', Maral Khodadadi, 05 Apr 2021
-
RC3: 'Comment on soil-2021-2', Anonymous Referee #3, 23 Mar 2021
The paper shows evidence of an increase in soil erosion rates following a change in land use. More specifically, the authors documented erosion rates in areas covered by forests and in areas where the same forests were replaced by vineyards. The erosion rates for the vineyards were approximately five times those documented for the forests.
The work is based on measurements made in two adjacent and similar hillslopes located in the Zarivar Lake watershed, Kurdestan Province, Iran. The authors selected these sites because this area, like many others in the country, was affected by this land-use conversion several years ago.
The sampling campaigns consisted of collecting a number of soil samples for Cs-137, excess Pb-210 and Pu-239,240 analyses. The area was affected by the Chernobyl accident. In this respect, the authors calculated the Cs-137 Chernobyl component using the ratio Cs-137/Pu-239,240 assuming that for bomb fallout this ratio is 38.4 (as suggested by Hodge, 1996). The proportion of the Chernobyl component was estimated to be ca. 50% of the total fallout (including the bomb-derived).
In general, the manuscript is acceptable and can be considered for publication. However, I have some comments about the methods and about some of the statements provided by the authors. These are as follows.
Lines 76-77 - The authors indicated that the global-derived 137Cs fallout ranges between 160 and 3200 Bqm-2 depending on latitude (UNSCEAR, 1969; Garcia Agudo, 1998). Here the authors should say that these two boundary values are referred to 1996 otherwise they need to be decay corrected. Please add some comments.
However, there are many exceptions to the map published by Garcia Agudo because 137Cs fallout is very sensitive to precipitation amount as well. See examples in Canada (Mabit et al., 2002), Spain (Navas et al., 2007; 2017), USA (Arnalds et al., 1989), India (Mishra and Sadasivan, 1972), Italy (Porto et al., 2009) etc. where the fallout basic line was correlated with the rainfall amount. Please consider to add some comments and citations about it.
I found interesting the approach used here to investigate the proportion of the Cs-137 Chernobyl fallout. This is already documented in previous papers but it appears to be an effective, independent, method to identify this component in the absence of direct measurements of Cs-134. In fact, the value of 50% is in line with what is documented in previous papers related to another Iranian province located not far from the study site (see Gharibreza et al., 2021; Vahabi-Moghaddam and Khoshbinfar, 2012). The authors may want to have a look at these papers.
Lines 243-244
The authors mentioned a 137Cs profile obtained in a lake in the vicinity of the study area. They reported the figure in the additional material but the source is not mentioned. Please add a citation for this study
Lines 307-309
The values of K-factor need units. Please add it
Lines 384-393
The authors emphasized that the three different FRNs account for diverse time spans. This is correct. They explained that 137Cs, because of the Chernobyl input, is more indicative of what happened after 1986 in terms of soil erosion. Similarly, 210Pb is more sensitive to the erosion rates occurred during the last 2-3 decades. On the contrary, the time frame captured by 239+240Pu has been recorded from mid-1960s onward. Based on these assumptions, the results obtained from 137Cs and 210Pb should be more correlated than the results obtained from 137Cs and 239+240Pu. The information provided in Fig. 7 for the forested hillslopes indicates the opposite i.e. the correlation between 137Cs and 239+240Pu is higher. Can they explain why?
Lines 507-508
The authors said that DMM was applied for vineyard. I think it is a mistake because the MBM2 was applied in cultivated areas. Is that correct?
Lines 511-515
The authors indicated that the change in land use from forest to vineyard resulted in a significant deterioration in soil quality as it was indicated by a significant decline in OM etc. This is in line with what was found by other authors for forest soils subjected to thinning (see Romeo et al., 2020; 2021). In those cases, 137Cs was correlated to the OM in different soil layers. The authors may want to have a look at these papers.
In Table 3 correct units of K are t ha hr Mj-1 ha-1 mm-1 (the exponent -1 is missing for ha). Please correct it
In Fig. 3b is reported Pu, not Pb as indicated in the caption (see page 35) – Please correct it
References
Arnalds et al. (1989) Cesium-137 in Montana soils. Health Physics Vol. 57, No. 6 (December), pp. 955-958.
Gharibreza et al. (2021). Investigation of onâsite implications of tea plantations on soil erosion in Iran using 137Cs method and RUSLE. Environmental Earth Sciences 80:34
Mabit et al. (2002). Quantification of soil redistribution and sediment budget in a Canadian watershed from fallout caesium-137 (137Cs) data. Can. J. Soil. Sci.
Mishra and Sadasivan (1972). Fallout radioactivity in Indian soils. Health Physics Vol. 23 (July), pp. 55-62.
Navas et al. (2007). Variability in 137Cs inventories and potential climatic and lithological controls in the central Ebro valley, Spain. Journal of Radioanalytical and Nuclear Chemistry, Vol. 274, No.2, 331–339.
Navas et al. (2017). Relating intensity of soil redistribution to land use changes in abandoned Pyrenean fields using fallout caesium-137. Land Degrad. Develop. 28: 2017–2029
Porto et al. (2009). Using caesium-137 and unsupported lead-210 measurements to explore the relationship between sediment mobilisation, sediment delivery and sediment yield for a Calabrian catchment. Marine and Freshwater research, 60: 680-689.
Romeo et al. (2020). Soil biological indicators and caesium-137 to estimate soil erosion in areas with different forest system management. Eur J For Res 139(1):67–81
Romeo, et al. (2021). The relationships between selected soil properties and caesiumâ137 identify organic carbon, nitrogen and water soluble phenols as indicators of soil erosion processes in different forest stands. J. For. Res.
Vahabi-Moghaddam M, Khoshbinfar S (2012). Vertical migration of 137Cs in the South Caspian soil. Radioprot 47(4):561–573
Citation: https://doi.org/10.5194/soil-2021-2-RC3 -
AC3: 'Reply on RC3', Maral Khodadadi, 05 Apr 2021
Dear Reviewer#3,
We would like to thank you for the helpful comments on our manuscript entitled “Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area”. Indeed, these valuable comments helped us to improve the content of our study.
We carefully considered the comments and revised our manuscript accordingly. Please find below our detailed responses.
Yours sincerely,
Maral Khodadadi on behalf of all the authors.
-
AC3: 'Reply on RC3', Maral Khodadadi, 05 Apr 2021
Status: closed
-
RC1: 'Comment on soil-2021-2', Anonymous Referee #1, 08 Feb 2021
General comments
The manuscript is based on the results of assessing the erosion/deposition rates using FRN as markers. The following questions arise when reading the manuscript:
1/ Based on Figure 4, we can conclude that the variability of 137Cs on a forested slope is higher than on vineyards. This clearly indicates that the Chernobyl fallout was extremely uneven in the area. It is obvious, that the initial 137Cs spatial variability of Chernobyl fallout too high for using the 137Cs technique for evaluating the soil losses based only on one reference location. It is necessary to evaluate 137Cs initial inventory minimum at three reference locations for the evaluation of the trend of initial fallout (See: Handbook for the Assessment of Soil Erosion and Sedimentation Using Environmental Radionuclides, F.Zapata for details). So authors aren't able to confirm the correctness of their evaluation of soil losses, based on Chernobyl-derived 137Cs because they have only one reference location on the distance of about 1 km from the studied site.
2/ On the other hand, if the mean 210Pb inventories values ââare approximately the same for the forested slope and vineyard (see bottom of page 9: 210Pbex inventories at 4068.3±2345.8 and 3990.1±2892.2 Bq m-2, respectively for forested and vineyard hillslopes) , then it is completely incomprehensible how such a large difference in net erosion rates (calculated based on 210Pbex) between the forested area and the vineyards was received (see Table 2). It is quite obvious that this is a very gross error in the calculations.
3/ The local spatial variation of the 137Cs fallout, as well as the other radionuclides, is >20% on the reference location. Isn't recommended to use FRD for evaluation of soil loss/gain in areas where initial fallout variability > 20% due to very high uncertainty of the results (see papers written by D. Walling and the other experts in the application of FRN for the evaluation of soil redistribution rates).
4/ Authors indicate that …The soil redistribution rates were, therefore, estimated using the Diffusion and Migration Model 185 (DMM) (Walling et al., 2002, 2014) in forested hillslope, Mass Balance Model II (MBM II) (Walling et al., 2002, 2014) in cultivated hillslope, and Modelling Deposition and Erosion rates with RadioNuclides (MODERN; Arata et al., 2016a, 2016b) – It is necessary to present the equations for all conversion models and to explain how you determine the parameters for each model.
5/ In addition application FRN for evaluation soil erosion rates in the forest isn't possible at all due to the influence of the crown of trees on the initial spatial variability.
Specific comments
1/ Are you sure that sampling only 40 cm layer is enough for determination of FRN total inventory in deposition location? How you can confirm that?
2/ In the Supplementary Material, the 137Cs depth distribution in the lake is presented. But it is completely incomprehensible how it was obtained?
3/ Figure 5 – how do you construct both maps with so high spatial resolution? Why was the total precipitation in April and May used to construct these maps? The accident at the Chernobyl nuclear power plant occurred on April 26 and the bulk of the Chernobyl fallout was observed until May 15 and was associated with the fallout of only one rain at a distance from Chernobyl.
4/ In the references, there are practically no papers on the use of 137 for assessing the erosion/sedimentation rates, prepared on the basis of research in the Chernobyl-affected areas (the UK, Poland, Belarus, Russia, Ukraine, Scandinavia, the Baltic States)
5/ It is not specified anywhere in the ms when the forest was cut down and vineyards were planted on the studied site.
Technical corrections:
1/ Introduction … than five times, increasing from 2.6 million ha (Wilber, 1948) to 18.5 million ha – should be more than seven times
-
AC1: 'Reply on RC1', Maral Khodadadi, 05 Apr 2021
Dear Reviewer#1,
We would like to thank you for the helpful comments on our manuscript entitled “Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area”. Indeed, these valuable comments helped us to improve the content of our study.
We carefully considered the comments and revised our manuscript accordingly. Please find below our detailed responses.
Yours sincerely,
Maral Khodadadi on behalf of all the authors.
-
AC1: 'Reply on RC1', Maral Khodadadi, 05 Apr 2021
-
RC2: 'Comment on soil-2021-2', Anonymous Referee #2, 11 Feb 2021
General comments
Overall, the study focuses on a relevant topic and presents interesting results and is therefore definitely worth publishing after some modifications and improvements to the current manuscript have been made. This manuscript represents valuable results, and a good approximation to better understand the differences and similarities between different methods to calculate soil redistribution rates and its relationship with some physical properties and soil nutrients.
The study includes interesting findings first reported in these areas of Iran and fits within SOIL scopes. However, in its current state, I think it requires quite a bit more work in terms of rearranging and editing before it is ready for publication. Overall, the study focuses on a relevant topic and presents interesting, results and is therefore worth publishing after some major modifications and improvements to the current manuscript have been made.
First, I think authors should clarify some of the previous reviewer questions. To avoid some repetition, I have been more focused on specific details. Apart from the general comments about each section, I have included some comments about the figures (14) and the text (17). An additional major issue I see in this manuscript is the enormous number of references included. If I am not wrong, there are more than 100 references. I think it is more than needed for a novel study.
Introduction
I think you need to emphasise this work's aims at the end of this section, the authors present an interesting study, but sometimes it is easy to get confused because the aim of the manuscript is repeated trough the introduction section. Thus, it could be useful to be more specific at the end of this section and reorder or rewrite some parts of the introduction.
Results and discussion
In this section, I would encourage the authors to synthesise the results and focus only on the results. Sometimes it seems that the discussion is a little bit mixed with the results.
Furthermore, I think more than 2800 words for the discussion section is excessive. In this section, authors tend to repeat most of the results, and there is an excessive number of comparisons with other studies. I think the manuscript could be reduced here. This statement is quite clear because authors have included more than 100 references, what it is just disproportionate. Don't you think? For example, 50-60 references are considered a high number of references, still acceptable but high.
Conclusions
I think that the text could be improved here (to avoid restricting it to a repetition of what was written before). The first 6 lines did not include a conclusion and just repeated previous parts of the manuscript. After a very rapid summary of the main results, you could stress the potential novel avenues for research in the future.
497 you could specify the location without using brackets, please rewrite the sentence.
496-500 Following table 1, the study pursued in Golestan Province with similar mean annual precipitation (MAP), showed significantly lower values than your study. Do authors think that all the difference could be due to the location even if both are located in the northern part of Iran?
Figures
Fig. 1 Subcatchment names are blurred and mixed with the division lines. I think you could create a different type of labels such as pin flags, for example.
The scale could be smaller, and a black-white style could fit better.
Instead of displaying the lake on the magnified Kurdistan province map, you could display the catchment limits.
Streams or rivers. These terms are pretty much interchangeable, but according to your scale, you have a stream with a length of 2000Km.
It will definitely help to visualise your study if you could include some pictures of the forest and vineyards.
Fig. 2 At least in my figure, the legend does not fit with the symbols. Furthermore, it is quite difficult to discern the separation between points. When plotting in Surfer (I think you used this software) the colours suffer a small colour change. Please try to modify your legend accordingly.
Is it true that your stream/river ends before reaching the outlet?
The height axis was not specified, and the meters cannot be seeing. If it is difficult to modify this in the software used, you could try to modify it by using additional graphical software.
The colour legend about the height is not specified. However, it would be nice to see the land use map over the DEM. It can be done in Surfer.
Fig. 5 I think you should use the same colour scale for both maps. Thus, you can easily compare them.
Fig. 6 What are the green dots? Please show it also in the legend.
Fig. 7 It is already nice, but you could improve by giving the equation the colour f the lines. However, do it carefully because maybe the green colour is too light to be correctly visualised.
Fig. 8 A little bit of colour here it would be nice.
Fig. 9 Same here, but just as a piece of advice.
Specific comments and technical corrections
Apart from the general comments, I have added some specific comments about the text and the figures. The authors might find them useful to improve their manuscript. "In my opinion", the inclusion of these points would significantly increase the audience interest of this manuscript that presents an interesting study. Here I have attached some typing error or minor suggestions to improve the text:
Line 38-39 I think this could better fit. "The transition/conversion from natural covers to cultivated lands have increased drastically."
Line 40 "more rapid than ever before" I think this is too much to state. Maybe something like this "the las century/or centuries" could do the job.
Line 55 "and the subsequent increase in soil erosion."
Line 55-56 This statement is too general. In the northern part of the Mediterranean region, especially in mountain agroecosystems, recent land-use changes produced just the inverse trend due to the land abandonment (that it is also a land use change). You could find many recent manuscripts using 137Cs and also 210Pb techniques that describe the issue, especially from Spanish an Italian catchments.
Line 63, 65, 69 just as a recommendation, I would prefer if you don't use the words "e.g." that much.
Line 98-100 These two sentences were repeated in the previous paragraph. I think you could reduce the text here and keep the MS focuses on your objectives.
Line 100 Did the authors missed a reference?
Line 104 runoff?
Line 111 "deforestation on and soil". Could it be mistyped?
Line 120 Figure two shows nothing related to 12 sub-watersheds. I think you should rewrite this paragraph to make it clearer for the readership. It is not very clear.
Line 121 It would be nice to include the data of max and min altitude here. You have graphically included in the figure, but it has not been specified.
Line 140 Besides,?
Line 143-15 A fragment could be missing. For what have they been constructed? I think it is obvious, but it would be nice to specify it; thus, making your point clearer to the readership.
Line 150 Keep the same style. Here you've used italics.
Line 247 This is an important part of the work. Thus, further description is needed.
Line 285 It would be nice to see a correlation matrix between all the properties.
Line 323 You cite a strong study about it, but you could also include the correlation of the data presented in Table 1. It will be only around 0.5 but still could support your discussion.
Citation: https://doi.org/10.5194/soil-2021-2-RC2 -
AC2: 'Reply on RC2', Maral Khodadadi, 05 Apr 2021
Dear Reviewer#2,
We would like to thank you for the helpful comments on our manuscript entitled “Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area”. Indeed, these valuable comments helped us to improve the content of our study.
We carefully considered the comments and revised our manuscript accordingly. Please find below our detailed responses.
Yours sincerely,
Maral Khodadadi on behalf of all the authors.
-
AC2: 'Reply on RC2', Maral Khodadadi, 05 Apr 2021
-
RC3: 'Comment on soil-2021-2', Anonymous Referee #3, 23 Mar 2021
The paper shows evidence of an increase in soil erosion rates following a change in land use. More specifically, the authors documented erosion rates in areas covered by forests and in areas where the same forests were replaced by vineyards. The erosion rates for the vineyards were approximately five times those documented for the forests.
The work is based on measurements made in two adjacent and similar hillslopes located in the Zarivar Lake watershed, Kurdestan Province, Iran. The authors selected these sites because this area, like many others in the country, was affected by this land-use conversion several years ago.
The sampling campaigns consisted of collecting a number of soil samples for Cs-137, excess Pb-210 and Pu-239,240 analyses. The area was affected by the Chernobyl accident. In this respect, the authors calculated the Cs-137 Chernobyl component using the ratio Cs-137/Pu-239,240 assuming that for bomb fallout this ratio is 38.4 (as suggested by Hodge, 1996). The proportion of the Chernobyl component was estimated to be ca. 50% of the total fallout (including the bomb-derived).
In general, the manuscript is acceptable and can be considered for publication. However, I have some comments about the methods and about some of the statements provided by the authors. These are as follows.
Lines 76-77 - The authors indicated that the global-derived 137Cs fallout ranges between 160 and 3200 Bqm-2 depending on latitude (UNSCEAR, 1969; Garcia Agudo, 1998). Here the authors should say that these two boundary values are referred to 1996 otherwise they need to be decay corrected. Please add some comments.
However, there are many exceptions to the map published by Garcia Agudo because 137Cs fallout is very sensitive to precipitation amount as well. See examples in Canada (Mabit et al., 2002), Spain (Navas et al., 2007; 2017), USA (Arnalds et al., 1989), India (Mishra and Sadasivan, 1972), Italy (Porto et al., 2009) etc. where the fallout basic line was correlated with the rainfall amount. Please consider to add some comments and citations about it.
I found interesting the approach used here to investigate the proportion of the Cs-137 Chernobyl fallout. This is already documented in previous papers but it appears to be an effective, independent, method to identify this component in the absence of direct measurements of Cs-134. In fact, the value of 50% is in line with what is documented in previous papers related to another Iranian province located not far from the study site (see Gharibreza et al., 2021; Vahabi-Moghaddam and Khoshbinfar, 2012). The authors may want to have a look at these papers.
Lines 243-244
The authors mentioned a 137Cs profile obtained in a lake in the vicinity of the study area. They reported the figure in the additional material but the source is not mentioned. Please add a citation for this study
Lines 307-309
The values of K-factor need units. Please add it
Lines 384-393
The authors emphasized that the three different FRNs account for diverse time spans. This is correct. They explained that 137Cs, because of the Chernobyl input, is more indicative of what happened after 1986 in terms of soil erosion. Similarly, 210Pb is more sensitive to the erosion rates occurred during the last 2-3 decades. On the contrary, the time frame captured by 239+240Pu has been recorded from mid-1960s onward. Based on these assumptions, the results obtained from 137Cs and 210Pb should be more correlated than the results obtained from 137Cs and 239+240Pu. The information provided in Fig. 7 for the forested hillslopes indicates the opposite i.e. the correlation between 137Cs and 239+240Pu is higher. Can they explain why?
Lines 507-508
The authors said that DMM was applied for vineyard. I think it is a mistake because the MBM2 was applied in cultivated areas. Is that correct?
Lines 511-515
The authors indicated that the change in land use from forest to vineyard resulted in a significant deterioration in soil quality as it was indicated by a significant decline in OM etc. This is in line with what was found by other authors for forest soils subjected to thinning (see Romeo et al., 2020; 2021). In those cases, 137Cs was correlated to the OM in different soil layers. The authors may want to have a look at these papers.
In Table 3 correct units of K are t ha hr Mj-1 ha-1 mm-1 (the exponent -1 is missing for ha). Please correct it
In Fig. 3b is reported Pu, not Pb as indicated in the caption (see page 35) – Please correct it
References
Arnalds et al. (1989) Cesium-137 in Montana soils. Health Physics Vol. 57, No. 6 (December), pp. 955-958.
Gharibreza et al. (2021). Investigation of onâsite implications of tea plantations on soil erosion in Iran using 137Cs method and RUSLE. Environmental Earth Sciences 80:34
Mabit et al. (2002). Quantification of soil redistribution and sediment budget in a Canadian watershed from fallout caesium-137 (137Cs) data. Can. J. Soil. Sci.
Mishra and Sadasivan (1972). Fallout radioactivity in Indian soils. Health Physics Vol. 23 (July), pp. 55-62.
Navas et al. (2007). Variability in 137Cs inventories and potential climatic and lithological controls in the central Ebro valley, Spain. Journal of Radioanalytical and Nuclear Chemistry, Vol. 274, No.2, 331–339.
Navas et al. (2017). Relating intensity of soil redistribution to land use changes in abandoned Pyrenean fields using fallout caesium-137. Land Degrad. Develop. 28: 2017–2029
Porto et al. (2009). Using caesium-137 and unsupported lead-210 measurements to explore the relationship between sediment mobilisation, sediment delivery and sediment yield for a Calabrian catchment. Marine and Freshwater research, 60: 680-689.
Romeo et al. (2020). Soil biological indicators and caesium-137 to estimate soil erosion in areas with different forest system management. Eur J For Res 139(1):67–81
Romeo, et al. (2021). The relationships between selected soil properties and caesiumâ137 identify organic carbon, nitrogen and water soluble phenols as indicators of soil erosion processes in different forest stands. J. For. Res.
Vahabi-Moghaddam M, Khoshbinfar S (2012). Vertical migration of 137Cs in the South Caspian soil. Radioprot 47(4):561–573
Citation: https://doi.org/10.5194/soil-2021-2-RC3 -
AC3: 'Reply on RC3', Maral Khodadadi, 05 Apr 2021
Dear Reviewer#3,
We would like to thank you for the helpful comments on our manuscript entitled “Deforestation effects on soil erosion rates and soil physicochemical properties in Iran: a case study of using fallout radionuclides in a Chernobyl contaminated area”. Indeed, these valuable comments helped us to improve the content of our study.
We carefully considered the comments and revised our manuscript accordingly. Please find below our detailed responses.
Yours sincerely,
Maral Khodadadi on behalf of all the authors.
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AC3: 'Reply on RC3', Maral Khodadadi, 05 Apr 2021
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5 citations as recorded by crossref.
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- First application of plutonium in soil erosion research on terraces Y. Guan et al. 10.1007/s41365-023-01210-6
- Plutonium isotopes can be used to model soil erosion in Kenya S. Dowell et al. 10.1007/s10653-024-02084-2
- Ultra-Trace Analysis of Fallout Plutonium Isotopes in Soil: Emerging Trends and Future Perspectives S. Dowell et al. 10.1007/s42250-023-00659-7
- Assessing the impact of land use and climate changes on the sedimentary regime of Valasht mountainous Lake (Iran) using radionuclide techniques M. Gharibreza et al. 10.1007/s12665-022-10484-9