Runoff of Water and Its Quality under the Combined Impact of Agricultural Activities and Urban Development in a Small River Basin
Round 1
Reviewer 1 Report
The article is of high scientific interest, since it is made from the standpoint of environmental management. The foundations of this direction were laid by A.P. Kapitsa, who in 1987 created the Department of Environmental Management at Moscow State University and put forward the main idea: to bring the ways of human economic activity in line with the laws of nature so as not to undermine its resources. The authors of the article showed that «the holistic solution of the soil protection problems in the catchment area and of hydroecological problems in river valley landscapes is most expected in the course of introduction of the river-basin nature management which implies the consideration of a basin as a single natural and anthropogenic system where the movement of the substance, energy and information occurs regularly from the watersheds to the thalweg of the river valley». (р.23).
River basins are the main elements of spatial organization of the landscape geosphere . In this context, basin approach became central in dealing with many fundamental and applied problems of geography. Basins are hierarchically structured integral formations anchoring many types of cycle of matter which are isolated within clear-cut orographic boundaries. Examination of the functioning of basins (studies into the redistribution of water flow, sediment load and dissolved solids) serves to investigate the interaction mechanisms of processes, assess the rate and directedness of transformation of topography as well as to make short-term forecast of the evolution of erosion-accumulation processes. Hence, currently there is a worldwide expansion research into small river basins in which changes of the influence of separate factors on the regime of functioning of lithodynamical systems is manifested relatively rapidly [Proc. 8th IAG. Int. Conf. on Geomorphology “Geomorphology and Sustainability” (August 27‒31, 2013, Paris), Paris, 2013, Abstracts Volumes 1–2.].
To development and approbation of approaches to the integral assessment of the hydroecological situation, the authors chose a complex object - the basin of a small river which combines the consequences of tilling the catchments and the influence of the urban area at the mouth (on the example of a typical river in the basin of the forest and steppe zone as is provided by observations of the hydrological regime).
The authors performed a large amount of work, including the following tasks: assessment of the modern state and prognosis of the probable changes of the environment in the course of the works for cleaning of a riverbed and of the banks of an aquatic object; taking of samples of water and bottom sediments; identification of the chemical composition and class of danger of the bottom sediments; estimation of the ecological condition of the flora and fauna; developing of recommendations for prevention of the unfavourable impacts; and restoration and sanitation of the natural environment during realization of the planned activities.
The publication of the article will allow a wide range of readers to get acquainted with the priority tasks of the sanitation of small rivers and their catchment area.
The article is written at a high scientific level.
The authors are well versed in the methods of environmental monitoring in relation to the rational nature management of river basins.
Interesting results have been obtained.
There are no comments to the authors on the content of the manuscript and the design of the text.
Author Response
Dear Reviewer, the authors thank you for your work and valuable comments, which we made the most of in the new version of the Manuscript.
Response to Reviewer #1 Comment
Comment:
The publication of the article will allow a wide range of readers to get acquainted with the priority tasks of the sanitation of small rivers and their catchment area.
Response: We thank the reviewer for the comments and we made some additions to the Manuscript under the influence of your assessment. Thank you.
Reviewer 2 Report
The novelty of the manuscript is not acceptable for the journal and it can be rejected .
Author Response
Response to Reviewer #2 Comments
Comments:
The novelty of the manuscript is not acceptable for the journal and it can be rejected .
Response: The authors regret that the Dear Reviewer did not substantiate his decision with specific arguments. But we dare to note that for a given territory, which is comparable in area to, for example, such a country as Burundi or Haiti, a study on a small river with a single gauging station made it possible to reveal many important features of Hydrology that can be extended to rivers of the same rank.
Reviewer 3 Report
This article comprehensively investigates the combined impacts of agricultural activities and urban development on the runoff and water quality of small rivers. The overall structure of the paper is well-developed, and the data is complete. After carefully reviewing the article, I would like to suggest that the author consider the following points:
(1) The author mentions, "The most agriculturally developed river basins are notable for the most essential changes of the water expenditure, drifts of suspensions of mud and intensiveness of the erosion [8]." In this context, has the author studied the impact of drifts of suspensions of mud on the water quality of small rivers?
(2) Is Formula (2) suitable for calculating the total indicator of bottom sediment contamination in the paper? Is this formula only applicable to small rivers, or is it suitable for all types of rivers?
(3) The water quality of rivers is closely related to dissolved oxygen. Has the author considered this aspect? What are the dissolved oxygen data?
(4) The overall length of the paper is quite lengthy, and I suggest that some non-essential information be included in supporting materials.
should be improved
Author Response
Dear Reviewer, the authors thank you for your work and valuable comments, which we made the most of in the new version of the Manuscript.
We thank the reviewer for the constructive comments and we carefully considered them in the revised paper and include the feedback as suggested. Revisions for Reviewer #3 are highlighted green color.
Response to Reviewer #3
Comment 1:
The author mentions, "The most agriculturally developed river basins are notable for the most essential changes of the water expenditure, drifts of suspensions of mud and intensiveness of the erosion [8]." In this context, has the author studied the impact of drifts of suspensions of mud on the water quality of small rivers?
Response:
The volume of sediment runoff at the hydrological station of the studied small river, unfortunately, is not included in the list of parameters of the Roshydromet service. Therefore, we calculated potential soil losses from arable land using the erosion model (Section 3.2). According to our estimates (Section 3.2), the volumes of the annual washout of the sediments amount to ca 2.2 thousand tons. According to the structure of the fluvial catchment network, about 40% of sediments are intercepted by ponds (this is indicated in Section 3.1.2). The regulated channel within the city limits also accumulates most of the eroded sediments. Section 3.10 also presents the results of the analysis of bottom sediments within the city by the concentration of heavy metals, which are predominantly of urban and industrial genesis.
In connection with these remarks, we have inserted into the text (lines 329–331):
Water quality in the urban area has become less dependent on solid sediment input from catchment due to interception in the widening zone created by dredging at the entrance to the city.
Comment 2: Is Formula (2) suitable for calculating the total indicator of bottom sediment contamination in the paper? Is this formula only applicable to small rivers, or is it suitable for all types of rivers?
RESPONSE:
The structure of formula (2) does not imply its dependence on the rank of the river, so it is universal. Moreover, the number of the considered elements, if necessary, can be increased, which will increase the objectivity of the assessment.
Comment 3: The water quality of rivers is closely related to dissolved oxygen. Has the author considered this aspect? What are the dissolved oxygen data?
RESPONSE:
Values of the chemical consumption of oxygen (COD) are given in Section 3.7. Values COD for six monitoring points были приведены в Appendix A (Table A1)
The authors added an explanation (lines 567–569):
The facts mentioned above are confirmed by the high values of the chemical consumption of oxygen (COD) equal to 25–34 mg L–1 as was detected during analysis of the studied samples (with excess of the maximum allowable COD value, which is set for water bodies within the boundaries of settlements (30 mg O / L) at the confluence with the tributary and at the mouth (Figure 2, f: sections 4 and 6)).
Comment 4: The overall length of the paper is quite lengthy, and I suggest that some non-essential information be included in supporting materials.
RESPONSE:
We agree that the volume of the article is large. However, given the complexity of the study, we consider all the selected components of the article important and deserving of a place in the main text. Ancillary data has already been included in the registered databases.
Comments on the Quality of English Language
should be improved
RESPONSE:
At the final stage, the authors involved a qualified translator and edited the text of the Article again. All changes (including some additional sentences) are shown in text in blue.
Reviewer 4 Report
The article presents a comprehensive analysis of the hydroecological situation in the urban river basin of Russia. The object of study is the Vezelka River and its drainage basin, which is characterized by significant anthropogenic impact due to urbanization. The aim of the authors is to develop and test approaches to the integrated assessment of the hydroecological situation based on hydrological, hydrochemical and hydrobiological data, as well as assessments of soil erosion, water quality and pollution of river bottom sediments. The results of the analysis, covering more than 70 years, revealed a steady decrease in water consumption since 1991, while over the past three decades the drop was 2.4 times. The reduction in the length of the river network over the past 250 years and the general poor quality of water indicate a serious degradation of the environment and the exhaustion of the self-cleaning potential of rivers. In addition, during the study, the quality of water during dry periods was studied and an excess of the maximum permissible concentrations in fishery reservoirs was found to be 2–10 times higher for Cu, Fe, ammonium, oil, and biochemical oxygen demand. The authors come to the conclusion that the constant deepening of the river bed without anti-erosion measures in the drainage basin and the poor organization of protective zones along the river banks lead to environmental degradation. As the final stage of the concept of basin nature management, they propose the reconstruction of the floodplain-river subsystem of river-valley landscapes. The article provides valuable information on the impact of urbanization on river basins and presents an integrated approach to its assessment. However, further research is needed to examine the effectiveness of the proposed management interventions. The article is recommended to researchers and practitioners interested in hydroecological assessments of urban river basins.
Notes:
1. At the end of the "Discussion" section, it would be useful to add the phrase "the studies carried out may be useful to specialists in the field of extraction and development of mineral water deposits" and add links to the works:
1. Ilyushin, Y.V.; Asadulagi, M.-A.M. Development of a Distributed Control System for the Hydrodynamic Processes of Aquifers, Taking into Account Stochastic Disturbing Factors. Water 2023, 15, 770. https://doi.org/10.3390/w15040770
2. Ilyushin, Y., Golovina, E. Stability of temperature field of the distributed control system (2020) ARPN Journal of Engineering and Applied Sciences, 15 (5), pp. 664-668.
In general, the work is positive, there are no critical comments. After adding the specified references, the work can be published.
Author Response
Dear Reviewer, the authors thank you for your work and valuable comments, which we made the most of in the new version of the Manuscript.
Reviewer 4
Comments:
However, further research is needed to examine the effectiveness of the proposed management interventions. After adding the specified references, the work can be published.
RESPONSE:
The authors added an explanation (lines 896–899, yellow highlight) :
The prospect of further research is related to the systematic monitoring of the effectiveness of management measures, based on new additions to the hydrological series in the context of a changing climate and increasing anthropogenic pressures on urban area.
We are grateful to the respected reviewer for the high appreciation of our study. suggested additions and references have been added to the text.
