Runoff Responses of Various Driving Factors in a Typical Basin in Beijing-Tianjin-Hebei Area

Round 1

Reviewer 1 Report

This study examined the impacts of runoff in a typical basin in the Beijing-Tianjin-Hebei region, considering the intensive human activities, rapid socioeconomic development, and climate change factors there. Generally the paper is well written. However, I think it still needs further improvement before publication. Here are some specific comments:

1.      Line 12 The study period was from 2006 to 2018, and it was perhaps not sufficient for understanding runoff and runoff depth responses. So the abstract, title, and other expressions need appropriate adjustments. Besides, the beginning of the abstract should be reorganized.

2.      Line 48-49 Summary analysis is suggested to move to the end of this paragraph. And the relative generalization in lines 68-69 needs further revision.

3.      Line 90-92 The specific environmental conditions and water issues should be introduced with more details, combined with the local background.

4.      Line 115-110 What was the function and importance of the specific study area to the Beijing-Tianjin-Hebei region? which should be explained in more detail. And it is advisable to revise the expressive logic for the environmental characteristics.

5.      Line 290-295 The impact of the natural vegetation on runoff was complex, the negative relationship between runoff and bare land with low vegetation cover needs a more detailed explanation.

6.      Line 334-343 What characteristics of the basin did the chosen index represent? The meaning of the indexes or the reasons for choosing them should be provided.

7.      Line 416-422 The double mass curve part barely related to the scientific question in this section, which did not verify the climatic effect on runoff. And it is not necessary to include a comparative method, results, and discussion.

8.      Line 470-473 The imbalanced runoff distribution description is inaccurate and needs to be corrected.

9.      Line 474-477 The runoff response to the land use change should be concluded; the current expression was not reasonable.

Author Response

Comments and Suggestions for Authors

This study examined the impacts of runoff in a typical basin in the Beijing-Tianjin-Hebei region, considering the intensive human activities, rapid socioeconomic development, and climate change factors there. Generally the paper is well written. However, I think it still needs further improvement before publication. Here are some specific comments:

1. Line 12 The study period was from 2006 to 2018, and it was perhaps not sufficient for understanding runoff and runoff depth responses. So the abstract, title, and other expressions need appropriate adjustments. Besides, the beginning of the abstract should be reorganized.

Response: We have changed the relative expressions and avoid to use “long term” in the abstract, title and other places. And we also revised the beginning of the abstract.

Revised text:

“Runoff responses of various driving factors in a typical basin in Beijing-Tianjin-Hebei area” (Line 2-3)

“Changes of land use and landscape caused by human activities, rapid socioeconomic development and climate change will disturb the water cycle process and impact the runoff.” (Line 9-10)

2. Line 48-49 Summary analysis is suggested to move to the end of this paragraph. And the relative generalization in lines 68-69 needs further revision.

Response: We have moved the summary analysis in Line 48-49 to the end of this paragraph, and modified the relative generalization.

Revised text:

“Considering the above factors, it is important to conduct the research on the relationships between the changes of land use, landscape pattern, climate as well as social economy and runoff.” (Line 66-68)

3. Line 90-92 The specific environmental conditions and water issues should be introduced with more details, combined with the local background.

Response: We have analyzed the specific environmental conditions and water issues in details combined with the local background, which is as follows:

Revised text:

“The Beijing-Tianjin-Hebei region in China has intensive human activity, which contributed a lot to the reshape of land use as well as landscape pattern and were prone to have impact on the runoff (Feng et al., 2022). And the high population density, rapid urbanization and socioeconomic development here exploited about 20 billion cubic meters of groundwater each year, which formed the hugest groundwater funnel under the urban agglomeration in this region (Zhou et al., 2020). Besides, the runoff here was impacted by climatic conditions because rainfall was brought by monsoon in temperate monsoon region. The fluctuated runoff would change groundwater depth and affect industrial, residential and agricultural water usage (Lu et al., 2021).” (Line 85-93)

Supplementary reference:

Lu, C., Song, Z., Wang, W., Zhang, Y., Si, H., Liu, B., Shu, L., 2021. Spatiotemporal variation and long-range correlation of groundwater depth in the Northeast China Plain and North China Plain from 2000∼ 2019. J. Hydrol. Reg. Stud. 37, 100888. (Line 536-537)

4. Line 115-110 What was the function and importance of the specific study area to the Beijing-Tianjin-Hebei region? which should be explained in more detail. And it is advisable to revise the expressive logic for the environmental characteristics.

Response: We have revised the expressive logic for the environmental characteristics of this basin and protrude the function and importance of it. And the revised text is like:

Revised text:

“The northwest region of the typical area has the higher terrain and the southeast region has the lower terrain, which make the altitude change between 128－2232 m. This basin has chestnut soil, cinnamon soil etc.. The alluvial parent soil is distributed along the banks of large rivers, with flat terrain and good natural conditions. And the parent material of diluvium with less mineral composition and poor nutrition does not have uniform soil texture. Besides, the loess parent material is widely distributed in this basin. The soil is deep and moderate in texture, rich in nutrients, and has strong water retention and drought resistance. Calcic layer and sandy gravel layer and so on are the soil barrier layers of this basin (Wei et al., 2022).

The study region has the temperate monsoon climate (Feng et al., 2022). The monsoon brings precipitation to the region from the sea in summer, which makes it a climate characterized by high temperature and rainfall in summer as well as dry and cold in winter. The annual precipitation is 400 ~ 800 mm in this basin. The Panjiakou dam in the downstream of this basin plays a role in adjusting runoff (Wei et al., 2021). Besides, this basin provides water resource for its downstream cities like Beijing and Tianjin, which are the megacities with the population of over 10 million (Yang et al., 2015). Beijing-Tianjin-Hebei region with increased population, changed land use as well as landscape and rapid economic development, are supposed to choose this typical basin to give more attention to runoff change (Dai et al., 2020; Guan et al., 2014).” (Line 107-125)

5. Line 290-295 The impact of the natural vegetation on runoff was complex, the negative relationship between runoff and bare land with low vegetation cover needs a more detailed explanation.

Response: We have explained the negative relationship between runoff and bare land with low vegetation cover in more detailed way combined with the complex impact of the natural vegetation on runoff.

Revised text:

“By contrast, when vegetation was destroyed and there was low vegetation coverage, the runoff was relatively low as previous study confirmed. Because the decline in the capacity of vegetation to conserve water led to the reduction of flow in dry season and the redistribution of runoff (Moniruzzaman et al., 2020). And this would also reduce the water and soil conservation capacity of the basin.” (Line 322-327)

6. Line 334-343 What characteristics of the basin did the chosen index represent? The meaning of the indexes or the reasons for choosing them should be provided.

Response: We concluded the reason for choosing these indexes and revised the relative expression.

Revised text:

“The chosen indexes were able to represent the landscape patch characteristics, landscape shape, landscape aggregation degree well.” (Line 231-233)

7. Line 416-422 The double mass curve part barely related to the scientific question in this section, which did not verify the climatic effect on runoff. And it is not necessary to include a comparative method, results, and discussion.

Response: We have deleted the method, results, and discussion of double mass curve considering its function for this section.

8. Line 470-473 The imbalanced runoff distribution description is inaccurate and needs to be corrected.

Response: We have modified the expression to make it more accurate.

Revised text: “Runoff had imbalanced distribution and there was rich water resource in central and south central areas.” (Line 486-487)

9. Line 474-477 The runoff response to the land use change should be concluded; the current expression was not reasonable.

Response: We concluded the runoff response to the land use change, and corrected current expression as follows:

Revised text:

“The forest in the north basin and the grassland in central and north region had negative effect on runoff because the permeability and water conductivity of forest soil were high. This negative effect also occurred in the bare land in southeast region. While artificial surface and land use intensity had positive impacts on runoff and runoff depth in most areas of the basin.” (Line 488-492)

Author Response File: Author Response.docx

Reviewer 2 Report

General comment

This study analyzed the long-term runoff responses to different driving factors including land use change, landscape pattern evolution, climate change and socioeconomy development. It is about the runoff responses in a typical basin of North China, which may provide enlightenment to water resource protection and water management. Thus, a minor revision for this manuscript is suggested before accept.

Specific comments

-          Line 27-69 (Introduction) This section introduced the background of hydrological cycle and runoff variation, and the different driving factors as well as their corresponding impacts were analyzed. While the status of water resource and runoff was suggested to be supplemented in the last paragraph so as to provide more evidence for the runoff conditions in the study area.

-          Line 104-105 (Material and methods) What was the data source of the subbasins division? It should be given to make more complemented information. And there was minor fault in Line 106 “The water resources in this basin is important to….”.

-          Line 113 (Material and methods) The expression “temperature monsoon climate” was incorrect, which should be changed.

-          Line 163, Line 186 (Material and methods) The method introduction was supposed to combine more background of this research.

-  Line 255-282 (Results and discussion) The result analysis between land use and

runoff should be more logical and well-organized. And the same problem also

occurred in Line 285-313.

-  Line 332 (Results and discussion) The background figure for GTWR between land

use and runoff is better to use land use data, rather than other data like DEM.

-  Line 384-392 (Results and discussion) The impact on runoff from climate factors were suggested to be analyzed as deeply as possible in this study region.

-  Line 394 (Results and discussion) Figure 7 should be modified in order to give

a good representation.

-          Line 425 (Results and discussion) The analysis for this section is recommend to combine the development background of Beijing-Tianjin-Hebei region, which is better to provide evidence for the scientific development of water resource under the great socioeconomic pressure.

-          Line 474-492 (Conclusion) The conclusion should be more refined and compact, which should include the most important results and grasp some essential laws. This conclusion length should be condensed to have a brief end of the whole manuscript.

Author Response

Comments and Suggestions for Authors

General comment

This study analyzed the long-term runoff responses to different driving factors including land use change, landscape pattern evolution, climate change and socioeconomy development. It is about the runoff responses in a typical basin of North China, which may provide enlightenment to water resource protection and water management. Thus, a minor revision for this manuscript is suggested before accept.

Specific comments

• Line 27-69 (Introduction) This section introduced the background of hydrological cycle and runoff variation, and the different driving factors as well as their corresponding impacts were analyzed. While the status of water resource and runoff was suggested to be supplemented in the last paragraph so as to provide more evidence for the runoff conditions in the study area.

Response: We have supplemented the conditions of water resource and runoff in order to provide more evidence for the analysis of runoff and resource.

Revised text:

“The Beijing-Tianjin-Hebei region in China has intensive human activity, which contributed a lot to the reshape of land use as well as landscape pattern and were prone to have impact on the runoff (Feng et al., 2022). And the high population density, rapid urbanization and socioeconomic development here exploited about 20 billion cubic meters of groundwater each year, which formed the hugest groundwater funnel under the urban agglomeration in this region (Zhou et al., 2020). Besides, the runoff here was impacted by climatic conditions because rainfall was brought by monsoon in temperate monsoon region. The fluctuated runoff would change groundwater depth and affect industrial, residential and agricultural water usage (Lu et al., 2021).” (Line 85-93)

• Line 104-105 (Material and methods) What was the data source of the subbasins division? It should be given to make more complemented information. And there was minor fault in Line 106 “The water resources in this basin is important to….”.

Response: We provided the data source for the subbasin division and gave the complemented website information. Besides, we corrected the minor fault for the expression “The water resources in this basin…”

Revised text:

“The annual runoff and runoff depth were measured in each monitoring site and the basin was divided into many subbasins (The subbasin division in this study is from https://www.hydrosheds.org/hydroatlas).” (Line 104-107)

“Besides, this basin provides water resource for its downstream cities like Beijing and Tianjin, which are the megacities with the population of over 10 million (Yang et al., 2015)” (Line 120-122)

• Line 113 (Material and methods) The expression “temperature monsoon climate” was incorrect, which should be changed.

Response: We have changed the word “temperature” into “temperate”.

Revised text:

“The study region has the temperate monsoon climate (Feng et al., 2022).” (Line 116)

• Line 163, Line 186 (Material and methods) The method introduction was supposed to combine more background of this research.

Response: We have modified the method section combined with more background of our research.

Revised text:

“The geographical regression relationship between land use and runoff could be explored by GTWR, because in which the correlations between explanatory variables and dependent variable could be calculated considering both temporal and geographical factors (Huang et al., 2010).” (Line 164-167)

“The gray correlation degree is used to measure the correlations of the variables from socioeconomic system and runoff. It core idea is to judge the closeness of their relationships by using the geometric similarity of the reference variable (runoff or runoff depth)and the comparison variable (socioeconomic indicators)” (Line 189-192)

• Line 255-282 (Results and discussion) The result analysis between land use and runoff should be more logical and well-organized. And the same problem also occurred in Line 285-313.

Response: We modified the result analysis between land use and runoff to make it more logical and well-organized in the two paragraphs.

Revised text: “During 2014－2018, the conversion of 586.16 km² of grassland to cropland and 100.10 km² of cropland to impervious surface increased the average runoff from 0.80 × 10⁸ m³ in 2014 to 1.48 × 10⁸ m³ in 2018, and runoff depth from 22.26 mm to 68.39 mm (Figure 2ab). The compacted soil contributed greatly to this result (Muñoz-Villers and McDonnell, 2013). In contrast, 233.04 km² of cropland and 1535.05 km² of grassland were converted to forest, and 337.14 km² and 707.75 km² of forest were transferred to cropland and grassland, respectively (Table 1). Thus, the runoff may be also affected by the expanded forest area.” (Line 304-310)

“This was because the soil was compacted and the gap was reduced with the increase of human activities and land use intensity,” (Line 354-355)

• Line 332 (Results and discussion) The background figure for GTWR between land use and runoff is better to use land use data, rather than other data like DEM.

Response: We try to modify the background of the figures for GTWR using land use data instead of DEM data. While there was large proportion of forest in the study region, which made the single color of the background and had unsatisfied visual effect. Thus, we reserved the original figure background.

• Line 384-392 (Results and discussion) The impact on runoff from climate factors were suggested to be analyzed as deeply as possible in this study region.

Response: We have analyzed the impact on runoff from climate factors as deeply as possible and revised the relative expression, which were as follows:

Revised text:

“This was because rainfall supplemented this region with more external water, and the decreased evaporation as well as temperature carried less water into air, which made less water supply loss to runoff. (Berghuijs et al., 2017).” (Line 408-410)

“This was because insufficient water supplementary to this region decreased runoff as a result.” (Line 413-414)

• Line 394 (Results and discussion) Figure 7 should be modified in order to give a good representation.

Response: We have modified Figure 7 (now is Figure 5) in order to give a good representation of climatic factors, which was shown in Line 416.

• Line 425 (Results and discussion) The analysis for this section is recommend to combine the development background of Beijing-Tianjin-Hebei region, which is better to provide evidence for the scientific development of water resource under the great socioeconomic pressure.
• Response: We have added the relative evidence for the water resource conditions under the great socioeconomic pressure in the study region and supplemented the relative expression as follows:

Revised text:

“High population density, rapid socioeconomic development and urbanization impacted the surface water and belowground water a lot in this region. The residential, industrial and agricultural water usage were affected as well (Zhou et al.，2020).” (Line 441-444)

• Line 474-492 (Conclusion) The conclusion should be more refined and compact, which should include the most important results and grasp some essential laws. This conclusion length should be condensed to have a brief end of the whole manuscript.

Response: We have refined and compacted the whole conclusion to make it more condensed and expressed briefly. And made it include the most important results and laws as well.

Revised text:

“The results of space-time analysis showed that the runoff and runoff depth had fluctuating increase trend during the study period. Runoff had imbalanced distribution and there was rich water resource in central and south central areas. (Line 485-487)

The forest in the north basin and the grassland in central and north region had negative effect on runoff because the permeability and water conductivity of forest soil were high. This negative effect also occurred in the bare land in southeast region. While artificial surface and land use intensity had positive impacts on runoff and runoff depth in most areas of the basin.” (Line 488-492)

“Increased rainfall and decreased temperature as well as potential evaporation promoted runoff and runoff depth in many periods.” (496-497)

Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript subject is interesting, but it is several limitations (especially regarding the small dimension of runoff data series) and flaws.

Broad comments

- Abstract must be reformulated: 1) The structure can be improved; 2) Methods are missing; 3) Most of the results are vague; and 4) Conclusions are almost absent. Please also see the specific comments related to the abstract.

- Keywords can be improved. Most of them are highly generic.

- English must be improved.

- References are poor and most of them belong to Chinese authors. This aspect must be improved by adding relevant references. This is mainly evident during the Introduction section.

- The chosen drainage basin must be characterized. The study area section is highly descriptive, missing important data like area/surface and indicators to understand/quantify the shape or the lithology/permeability degree of this basin. Rainfall information (quantified) is also missing. Are there dams in the basin that can affect runoff?

- 13 years are not enough to safely identify temporal trends in runoff or rainfall. Therefore, the results presented in section 3.1 are not satisfactory and valid to take any conclusions regarding temporal trends.

- The values presented in section 3.3 (pages 7 and 8) are difficult to interpret. The written text (and the English) is hard to follow, making interpretation difficult. Figure 4 is also difficult to decode. Simpler charts would facilitate interpretation.

- Figure 5 is not clearly described in the text. Maybe if the authors include the values obtained in a table, the visualization and comprehension would be clearer. Additionally, the title of the figure mentions only 2018, while the text mentions the period 2006-2018.

- There are several methodological aspects described in the results sections that were not mentioned in the material and methods sections. Please correct this.

- The results presented in section 3.6 are very strange. First, what are the unit of analysis used for the socioeconomic indicators? There are no negative correlations? This means that higher values of runoff occur where there are more population, higher GDP, higher income, etc.? But upstream areas surely record lower runoff values than downstream areas. Does this mean that downstream areas are more populated and wealthier than upstream areas? On the other hand, the socioeconomic values do not change significantly every year, unlike runoff, which is dependent on rainfall variability. Thus, in my opinion there is no relevant effect of socioeconomic variables on runoff.

Specific comments

The following are more specific/detailed comments and advices that should be considered:

- Page 1, lines 9-10: “Intensive human activities, rapid socioeconomic development and climate change will disturb the water cycle process and impact the runoff”. These impacts will not only be recorded in the future, so please change/remove “will” from the sentence.

- The study area should be presented earlier in the abstract. Suggestion: “This study analyzed the long-term runoff responses to different driving factors in a basin of North China”. Additionally, the name of the drainage basin should also be mentioned in the abstract.

- Page 1, lines 13-14: “Complex and diverse landscape with high shape index intercepted runoff to some extent”. This sentence is not clear. What do you mean by “intercepted” in this context? Please rephrase.

- Page 1, lines 14-16: “Besides, the runoff and runoff depth were promoted in many periods when there were increasing precipitation as well as reducing temperature and potential evaporation”. The first part of the sentence is obvious (runoff is “promoted” by rainfall), so there is no need to be mentioned in the abstract.

- Page 1, lines 17-19: “In addition, population density and rural as well as urban economic development put heavy burden on runoff and water resource in this basin”. What do you mean by “rural”? Rural population? Rural activities? This sentence is vague and does not convey what is meant by “heavy burden”. Please rephrase adding data/results that demonstrate the effects of these driving factors.

- Page 1, lines 30-31: “There was runoff variation due to the changed hydrological process caused by human activities and climatic factors”. Please add references here.

- Page 3, line 97: What do you mean by typical basin? This is a strange adjective in this context. Additionally, why did you choose this drainage basin?

- Figure 2: In what part of the basin were these values obtained? This is not mentioned. Additionally, the annual rainfall values should also be included in these charts.

- Figure 6: If the goal is to identify the associations between landscape indicators and runoff/runoff depth, why do the authors present the correlations between landscape indicators? A simple table with correlations between each landscape indicators and runoff/runoff depth would be enough and clearer.

- Page 11, line 332: “It can be discovered that patch density had positive correlation with runoff”. The correlation coefficient in figure 6 is only 0.247. The highest correlation coefficient with runoff/runoff depth is 0.401 (AI), which demonstrates a weak association between any indicator and runoff.

Author Response

Comments and Suggestions for Authors

The manuscript subject is interesting, but it is several limitations (especially regarding the small dimension of runoff data series) and flaws.

Broad comments

- Abstract must be reformulated: 1) The structure can be improved; 2) Methods are missing; 3) Most of the results are vague; and 4) Conclusions are almost absent. Please also see the specific comments related to the abstract.

Response: Thanks a lot for your good suggestion! We improved the structure of the abstract and supplemented the methods. Besides, we tried to removed the vague results and described the results as clearly as possible. Finally, we added the absent conclusion as well. And the modified abstract is as follows:

Revised text:

“Changes of land use and landscape caused by human activities, rapid socioeconomic development and climate change disturb the water cycle process and impact the runoff. This study analyzed the runoff responses to different driving factors in a typical basin in the Beijing-Tianjin-Hebei region of North China combined with methods like geographically and temporally weighted regression, landscape pattern indexes and Budyko theory. The results indicated that the runoff and runoff depth were higher in the central and south part, and were lower in the northwest of the basin. And the average runoff increased at the end of the study period. Artificial surface and land use intensity exerted positive impacts on runoff and runoff depth in most areas. Complex and diverse landscape with high shape index blocked runoff to some extent. Besides, runoff depth would increase by 0.724 mm or decrease by 0.069 mm when the rainfall or potential evaporation increased by 1mm. In addition, population density and the economic development in both rural as well as urban areas put heavy burden on runoff and water resource in this basin. From above it could be concluded that the impacts on runoff due to the environmental change brought by human activities could not be neglected though the runoff was also greatly affected by climate change. This study reflected the runoff responses to driving factors in a typical basin of North China, which will provide reference for water resource protection and give enlightenment to water management.” (Line 9-23)

- Keywords can be improved. Most of them are highly generic.

Response: We have improved our keywords to avoid to be highly generic.

Revised text:

“Runoff response; Land use change; Landscape pattern evolution; Climate change; Socioeconomic development” (Line 25-26)

- English must be improved.

Response: We have polished the expression of this manuscript again and corrected some minor mistakes.

- References are poor and most of them belong to Chinese authors. This aspect must be improved by adding relevant references. This is mainly evident during the Introduction section.

Response: We have changed many References from abroad authors, especially the references in the Introduction section.

Supplementary references:

Butt, M. J., Bilal, M., 2011. Application of snowmelt runoff model for water resource management. Hydrol. Process. 25(24), 3735-3747.

Sample, D. J., Liu, J., 2014. Optimizing rainwater harvesting systems for the dual purposes of water supply and runoff capture. J. Clean. Prod. 75, 174-194.

Moniruzzaman, M., Thakur, P. K., Kumar, P., Ashraful Alam, M., Garg, V., Rousta, I., Olafsson, H., 2020. Decadal urban land use/land cover changes and its impact on surface runoff potential for the Dhaka City and surroundings using remote sensing. Remote Sens. 13(1), 83.

Hosseiny, H., Crimmins, M., Smith, V. B., Kremer, P., 2020. A generalized automated framework for urban runoff modeling and its application at a citywide landscape. Water, 12(2), 357.

Boardman, J., Evans, R., 2020. The measurement, estimation and monitoring of soil erosion by runoff at the field scale: Challenges and possibilities with particular reference to Britain. Prog. Phys. Geog. 44(1), 31-49.

Love, D., Uhlenbrook, S., Corzo-Perez, G., Twomlow, S., van der Zaag, P., 2010. Rainfall–interception–evaporation–runoff relationships in a semi-arid catchment, northern Limpopo basin, Zimbabwe. Hydrol. Sci. J. 55(5), 687-703.

Trancoso, R., Larsen, J. R., McAlpine, C., McVicar, T. R., Phinn, S., 2016. Linking the Budyko framework and the Dunne diagram. J. Hydrol. 535, 581-597.

Rasmussen, R., Liu, C., Ikeda, K., Gochis, D., Yates, D., Chen, F., Tewari, M., Barlage, M., Dudhia, J., Y, W., Miller, K., Arsenault, K., Grubišić, V., Thompson, G., Gutmann, E., 2011. High-resolution coupled climate runoff simulations of seasonal snowfall over Colorado: a process study of current and warmer climate. J. Clim. 24(12), 3015-3048.

- The chosen drainage basin must be characterized. The study area section is highly descriptive, missing important data like area/surface and indicators to understand/quantify the shape or the lithology/permeability degree of this basin. Rainfall information (quantified) is also missing. Are there dams in the basin that can affect runoff?

Response: Thanks a lot for the good suggestion. We have supplemented some important information for the study area, like its area, soil type, parent material, water retention ability and soil barrier layers. The quantified annual rainfall information was also added. And the Panjiakou dam adjusting runoff was also supplemented.

Revised text:

“The typical basin with the area of about 3.95 × 10⁴ km² for this research is located in the north region of the Beijing-Tianjin-Hebei region in China (Figure 1).” (Line 103-104)

“The northwest region of the typical area has the higher terrain and the southeast region has the lower terrain, which make the altitude change between 128－2232 m. This basin has chestnut soil, cinnamon soil etc.. The alluvial parent soil is distributed along the banks of large rivers, with flat terrain and good natural conditions. And the parent material of diluvium with less mineral composition and poor nutrition does not have uniform soil texture. Besides, the loess parent material is widely distributed in this basin. The soil is deep and moderate in texture, rich in nutrients, and has strong water retention and drought resistance. Calcic layer and sandy gravel layer and so on are the soil barrier layers of this basin (Wei et al., 2022).” (Line 107-115)

“The annual precipitation is 400 ~ 800 mm in this basin. The Panjiakou dam in the downstream of this basin plays a role in adjusting runoff (Wei et al., 2021).” (Line 119-120)

Supplementary references:

Wei, X., Sun, H., Chen, Z., Li, X., Wei, H., Jia, W., Li, W., 2022. Element migration and enrichment characteristics of bedrock–regolith–soil–plant continuum system in the chestnut planting area, Chengde, China. Acta Geochimica 41(5), 839-860.

Wei, M., Huang, S., Li, L., Zhang, T., Akram, W., Khatoon, Z., Renaud, F. G., 2021. Evolution of water quality and biota in the Panjiakou Reservoir, China as a consequence of social and economic development: implications for synergies and trade-offs between Sustainable Development Goals. Sustain. Sci. 17, 1385–1404.

- 13 years are not enough to safely identify temporal trends in runoff or rainfall. Therefore, the results presented in section 3.1 are not satisfactory and valid to take any conclusions regarding temporal trends.

Response: We replaced the word “trend” with more suitable expression, and similar problems were also corrected in conclusion and abstract.

Revised text:

“As is shown that the regional runoff increased at the end of the study period than that of the beginning of the period.” (Line 239-240)

“Figure 2b shows that the runoff depth in the basin also increased in 2018 than that of 2006, and the slope of its trend line was larger than that of the runoff (Rets et al., 2019).” (Line 244-245)

“The results of space-time analysis showed that the runoff and runoff depth increased at the end of the study period.” (Line 485-486)

“And the average runoff increased at the end of the study period.” (Line 15)

- The values presented in section 3.3 (pages 7 and 8) are difficult to interpret. The written text (and the English) is hard to follow, making interpretation difficult. Figure 4 is also difficult to decode. Simpler charts would facilitate interpretation.

Response: We have transformed Figure 4 into Table 1, which was showed as the conversion matrixes of land uses in various periods clearly. Then we reorganized the relative analysis and expression in section in order to make it easier to be understood. Appropriate modifications have also been made in the written text.

Revised text:

“Cropland was converted into 194.50 km² of forest and 379.33 km² of grassland, and grassland was converted to 203.41 km² of cropland and 503.46 km² of forest from 2006 to 2010 (Table 1). The large amount of cropland and grassland transferred into other land uses and other land uses transferred into forest made the average runoff of the watershed increased from 0.83 × 108 m³ in 2006 to 1.07 × 108 m³ in 2010 (Figure 2a).” (Line 282-286)

“While agricultural machinery or livestock in agricultural activities would compact the soil, reduce soil pores and soil permeability, so as to reduce the amount of water absorbed by the soil and increase surface runoff, thus the runoff reduction from 2006 to 2010 may be caused by the increase of cropland though the increasing forest adjusted runoff to some degree (Muñoz-Villers and McDonnell, 2013).” (Line 288-292)

“With the time evolution, 132.75 km², 351.84 km² and 60.24 km² of cropland were converted into forest, grassland and artificial surface from 2010 to 2014, respectively (Table 1). And grassland was converted into 241.04 km² of cropland and 678.09 km² of forest.” (Line 293-295)

“And previous studies had pointed out that the water absorption of root of forest soil was greater than that of grassland soil, so the large areas of the transferred forest in 2014 (680.04 km2) further reduced surface runoff in 2014 (Figure 2a) compared with that in 2010 (Alaoui et al., 2011).” (Line 300-303)

“During 2014－2018, the conversion of 586.16 km² of grassland to cropland and 100.10 km² of cropland to impervious surface increased the average runoff from 0.80 × 108 m3 in 2014 to 1.48 × 108 m³ in 2018, and runoff depth from 22.26 mm to 68.39 mm (Figure 2ab). The compacted soil contributed greatly to this result (Muñoz-Villers and McDonnell, 2013). In contrast, 233.04 km² of cropland and 1535.05 km² of grassland were converted to forest, and 337.14 km² and 707.75 km² of forest were transferred to cropland and grassland, respectively (Table 1). Thus, the runoff may be also affected by the expanded forest area.” (Line 304-310)

“By contrast, when vegetation was destroyed and there was low vegetation coverage, the runoff was relatively low as previous study confirmed. Because the decline in the capacity of vegetation to conserve water led to the reduction of flow in dry season and the redistribution of runoff (Moniruzzaman et al., 2020). And this would also reduce the water and soil conservation capacity of the basin.” (Line 322-327)

- Figure 5 is not clearly described in the text. Maybe if the authors include the values obtained in a table, the visualization and comprehension would be clearer. Additionally, the title of the figure mentions only 2018, while the text mentions the period 2006-2018.

Response: Well, Figure 5 (now is Figure 4) showed the Geographically and temporally weighted regression relationships between land use and runoff in 2018. And the regression relationships for runoff in 2006, 2010 and 2014 are in Figure S1-3 in our Supplementary Material. The regression relationships for runoff depth in 2006, 2010, 2014 and 2018 are in Figure S4-7. In Figure 5 (now is Figure 4), the spatiotemporal distributions for the regression relationships between land use and runoff can be shown clearly. And the spatial relationships can not be descripted clearly if the coefficients filled in a table, which may be inconvenient for the corresponding analysis. So, we think it might be better to retain this figure.

- There are several methodological aspects described in the results sections that were not mentioned in the material and methods sections. Please correct this.

Response: Well, we supplemented the relative theoretical explanation and ecological senses for the landscape pattern indexes in Section 2.6. Besides, the Pearson correlation coefficients were calculated using Pearson's correlation analysis. We have supplemented the reference instead of introducing its theory in details because it is a common statistical method (Ly et al., 2018).

Revised text:

“Specifically, NP denotes the number of patches in the basin and PD represented the density of certain patches in the watershed landscape. LPI is the proportion of the largest patch in a certain patch type to the whole landscape area, which reflects the dominant species in the landscape and reflect the direction and intensity of human activities. ED is the length of landscape element boundary per unit area (Šímová and Gdulová, 2012).

 Besides, SHAPE_MN describes the patch structure of the landscape as that of the average patch characteristic, which provides a measure of central tendency in the corresponding patch characteristic. LSI reflects the shape complexity of the overall landscape and ENN_MN is used to measure the Euclidean Nearest Neighbor Distance Distribution. COHESION is able to reflect the combination degree between patches in the landscape, and CONTAG represents the agglomeration degree or extension trend of different patch types in the landscape. AI is usually adopted to describe the aggregation of the landscape. SHDI based on information theory is a measurement index to measure the diversity of ecological landscape (Šímová and Gdulová, 2012). The chosen indexes were able to represent the landscape patch characteristics, landscape shape, landscape aggregation degree well.” (Line 217-233)

Supplementary reference:

Ly, A., Marsman, M., Wagenmakers, E. J., 2018. Analytic posteriors for Pearson's correlation coefficient. Stat. Neerl. 72(1), 4-13.

Šímová, P., & Gdulová, K., 2012. Landscape indices behavior: A review of scale effects. Appl. geogr. 34, 385-394.

- The results presented in section 3.6 are very strange. First, what are the unit of analysis used for the socioeconomic indicators? There are no negative correlations? This means that higher values of runoff occur where there are more population, higher GDP, higher income, etc.? But upstream areas surely record lower runoff values than downstream areas. Does this mean that downstream areas are more populated and wealthier than upstream areas? On the other hand, the socioeconomic values do not change significantly every year, unlike runoff, which is dependent on rainfall variability. Thus, in my opinion there is no relevant effect of socioeconomic variables on runoff.

 Response: Well, the the units for the socioeconomic indicators are at the end of Section 2.5 (Line 209-211). And we only tried to analyse the closeness between socioeconomic indicators and runoff because of the water resource pressure brought by socioeconomic development. So there are no positive or negative correlations, there is only correlation degree representing the closeness.

Specific comments

The following are more specific/detailed comments and advices that should be considered:

- Page 1, lines 9-10: “Intensive human activities, rapid socioeconomic development and climate change will disturb the water cycle process and impact the runoff”. These impacts will not only be recorded in the future, so please change/remove “will” from the sentence.

Response: Thanks for the good suggestion, and we revised the sentence and removed “will” from the original sentence.

Revised text:

“Changes of land use and landscape caused by human activities, rapid socioeconomic development and climate change disturb the water cycle process and impact the runoff.” (Line 9-10)

- The study area should be presented earlier in the abstract. Suggestion: “This study analyzed the long-term runoff responses to different driving factors in a basin of North China”. Additionally, the name of the drainage basin should also be mentioned in the abstract.

Response: We have modified the abstract and presented the study area earlier, which was expressed as:

Revised text:

“This study analyzed the runoff responses to different driving factors in a typical basin in the Beijing-Tianjin-Hebei region of North China….” (Line 10-12)

- Page 1, lines 13-14: “Complex and diverse landscape with high shape index intercepted runoff to some extent”. This sentence is not clear. What do you mean by “intercepted” in this context? Please rephrase.

Response: We have changed the original vocabulary and use “block” to describe the blocking effect on runoff from landscape (Zhang et al., 2019). And all the relative expression were replaced through the whole manuscript including abstract, results and discussion as well as conclusion.

Revised text:

“Complex and diverse landscape with high shape index blocked runoff to some extent.” (Line 16-17)

“There were significant negative correlations between SHAPE_MN and runoff in the whole study period (Figure 6) and in 2018 (Figure S8a), which was likely because the complex landscape diverted and blocked the runoff and made the low runoff under the complex landscape (Wang et al., 2011; Zhang et al., 2019).” (Line 372-376)

“Generally speaking, the complexity of landscape structure increased with the increasing diversity index (Figure 6), which enhanced the blocking effect of landscape on runoff and made the negative correlation with SHDI and runoff depth (Yan et al., 2016; Zhang et al., 2019b).” (Line 384-387)

“Landscape with high Shannon's diversity index enhanced the blocking effect on runoff and reduced runoff depth.” (Line 494-495)

Supplementary reference:

Zhang, Y., Bi, Z., Zhang, X., Yu, Y., 2019. Influence of landscape pattern changes on runoff and sediment in the Dali River watershed on the Loess Plateau of China. Land, 8(12), 180.

- Page 1, lines 14-16: “Besides, the runoff and runoff depth were promoted in many periods when there were increasing precipitation as well as reducing temperature and potential evaporation”. The first part of the sentence is obvious (runoff is “promoted” by rainfall), so there is no need to be mentioned in the abstract.

Response: Thanks for this suggestion. We deleted the expression “Besides, the runoff and runoff depth were promoted in many periods when there were increasing precipitation as well as reducing temperature and potential evaporation.” and only reserved the results of Budyko theory.

- Page 1, lines 17-19: “In addition, population density and rural as well as urban economic development put heavy burden on runoff and water resource in this basin”. What do you mean by “rural”? Rural population? Rural activities? This sentence is vague and does not convey what is meant by “heavy burden”. Please rephrase adding data/results that demonstrate the effects of these driving factors.

Response: We intended to express the heavy burden on runoff and water resource from the rural economic development and urban economic development instead of rural population or rural activities. So, we modified our expression as “the economic development in both rural as well as urban areas”. And the relative sentence was changed as follows:

Revised text:

“In addition, population density and the economic development in both rural as well as urban areas put heavy burden on runoff and water resource in this basin.” (Line 19-20)

- Page 1, lines 30-31: “There was runoff variation due to the changed hydrological process caused by human activities and climatic factors”. Please add references here.

Response: We have added the relative references as follows:

Supplementary reference:

“Lu, C., Song, Z., Wang, W., Zhang, Y., Si, H., Liu, B., Shu, L., 2021. Spatiotemporal variation and long-range correlation of groundwater depth in the Northeast China Plain and North China Plain from 2000∼ 2019. J. Hydrol. Reg. Stud. 37, 100888.”

- Page 3, line 97: What do you mean by typical basin? This is a strange adjective in this context. Additionally, why did you choose this drainage basin?

Response: Well, we chose this basin as the typical basin to conduct our study because it combined several important driving factors. Firstly, this basin provides water resource for its downstream megacities like Beijing and Tianjin, its research of water resource was of great significance. Secondly, it was located in Beijing-Tianjin-Hebei region with intensive human activities, which had obvious impacts on the changes of land use and landscape. Thirdly, the supplementary for the water resource in this basin largely depended on the precipitation brought by monsoon. Considering various factors comprehensively, this basin was a typical basin that could be worth studying the impact of various factors on runoff.

Revised text:

“The typical basin with the area of about 3.95×104 km2 for this research is located in the north region of the Beijing-Tianjin-Hebei region in China (Figure 1). The annual runoff and runoff depth were measured in each monitoring site and the basin was divided into many subbasins (The subbasin division in this study is from https://www.hydrosheds.org/hydroatlas). The northwest region of the typical area has the higher terrain and the southeast region has the lower terrain, which make the altitude change between 128－2232 m. This basin has chestnut soil, cinnamon soil etc.. The alluvial parent soil is distributed along the banks of large rivers, with flat terrain and good natural conditions. And the parent material of diluvium with less mineral composition and poor nutrition does not have uniform soil texture. Besides, the loess parent material is widely distributed in this basin. The soil is deep and moderate in texture, rich in nutrients, and has strong water retention and drought resistance. Calcic layer and sandy gravel layer and so on are the soil barrier layers of this basin (Wei et al., 2022).

The study region has the temperate monsoon climate (Feng et al., 2022). The monsoon brings precipitation to the region from the sea in summer, which makes it a climate characterized by high temperature and rainfall in summer as well as dry and cold in winter. The annual precipitation is 400 ~ 800 mm in this basin. The Panjiakou dam in the downstream of this basin plays a role in adjusting runoff (Wei et al., 2021). Besides, this basin provides water resource for its downstream cities like Beijing and Tianjin, which are the megacities with the population of over 10 million (Yang et al., 2015). Beijing-Tianjin-Hebei region with increased population, changed land use as well as landscape and rapid economic development, are supposed to choose this typical basin to give more attention to runoff change (Dai et al., 2020; Guan et al., 2014).” (Line 103-125)

- Figure 2: In what part of the basin were these values obtained? This is not mentioned. Additionally, the annual rainfall values should also be included in these charts.

Response: These values were the average runoff and runoff depth of runoff monitoring stations in the typical basin in Figure 1. We added the relative explanation as follows. Additionally, the annual rainfall description was included in Figure 7a in the section of climatic impacts. So we did not continue to supplement the figure in this section.

Revised text:

“The change of the average runoff and runoff depth of runoff monitoring stations (Figure 1) over time in the typical basin is shown in Figure 2.” (Line 239-239)

- Figure 6: If the goal is to identify the associations between landscape indicators and runoff/runoff depth, why do the authors present the correlations between landscape indicators? A simple table with correlations between each landscape indicators and runoff/runoff depth would be enough and clearer.

Response: Well, that’s the good advice, so we changed the relative figure into table to show the results, which were only include the correlations between landscape indicators and runoff/runoff depth. And it had a clearer presentation than before. And we also adjusted the number of the figures in the other places of the manuscript.

Revised text: Line 391

- Page 11, line 332: “It can be discovered that patch density had positive correlation with runoff”. The correlation coefficient in figure 6 is only 0.247. The highest correlation coefficient with runoff/runoff depth is 0.401 (AI), which demonstrates a weak association between any indicator and runoff.

Response: Well, the Pearson correlation result in Table 1 showed that some indicators did have association with runoff and runoff at the significance level of p<0.05. Many statistical results were significant, which indicated that landscape pattern indexes did have impacts on runoff or runoff depth. When the coefficient was in 0.2~0.4, it showed a moderate relationship between runoff and indicator. When the coefficient was in 0.4~0.7, it represented a close relationship. And a very close relationship would be verified if the coefficient > 0.7. Whether the coefficients >0.4 or <0.4, the close or moderate relationships would be verified and explained at the significant level in this study. And the low coefficient representing moderate relationship also had certain value if it was significant.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors answer satisfactorily to the comments made and apply several modifications to the manuscript, improving its overall quality.