Quantitative Evaluation of Runoff Simulation and Its Driving Forces Based on Hydrological Model and Multisource Precipitation Fusion
Round 1
Reviewer 1 Report
Thank you for an interesting manuscript.
1. What is the main question addressed by the research? The authors presented a quantitative evaluation of runoff simulation with a focus on multi-source precipitation product fusion.
2. Do you consider the topic original or relevant in the field? Does it address a specific gap in the field? Yes the topic is relevant and timely in the field. The fusion of multi-source precipitation data and several methods are evaluated in this manuscript.
3. What does it add to the subject area compared with other published material? It presents another approach to quantify runoff while dealing with prescription data and spatial distribution of precipitation across catchment areas.
4. What specific improvements should the authors consider regarding the methodology? What further controls should be considered? No comments.
5. Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed? Yes, the conclusions are consistent with the results presented in this study.
6. Are the references appropriate? Yes
7. Please include any additional comments on the tables and figures. No comments.
Author Response
Thank you for an interesting manuscript.
1、What is the main question addressed by the research? The authors presented a quantitative evaluation of runoff simulation with a focus on multi-source precipitation product fusion.
2、Do you consider the topic original or relevant in the field? Does it address a specific gap in the field? Yes the topic is relevant and timely in the field. The fusion of multi-source precipitation data and several methods are evaluated in this manuscript.
3、What does it add to the subject area compared with other published material? It presents another approach to quantify runoff while dealing with prescription data and spatial distribution of precipitation across catchment areas.
4、What specific improvements should the authors consider regarding the methodology? What further controls should be considered? No comments.
Reply：Thank you very much for your professional advice.
Since BMA relies on all en-semble forecast members, poor regional simulation of a particular forecast member can affect the overall forecast results. Therefore, Our research selects the OBIPP from 57 BIPP based on the overall characteristics of simulations and observations to obtain more accurate precipitation information of data-sparse regions.
In addition, Considering the monthly precipitation variation across the YRB, the optimal weights of BMA were calculated month by month.
5、Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed? Yes, the conclusions are consistent with the results presented in this study.
6、Are the references appropriate? Yes
7、Please include any additional comments on the tables and figures. No comments.
Reply: Thank you very much for your professional advice. Some figures and tables have been modified.
Author Response File: 
Author Response.doc
Reviewer 2 Report
figure 1 request a better quality. The images are grainy and the writing too.
figure 5 the data in the legend cannot be distinguished. Enlarge it.
Author Response
1、Figure 1 request a better quality. The images are grainy and the writing too.
Reply: Thank you very much for your professional advice. It’s done.
2、Figure 5 the data in the legend cannot be distinguished. Enlarge it.
Reply: Thank you very much for your professional advice. It’s done. As shown in the revised Figure 6.
Author Response File: Author Response.doc
Reviewer 3 Report
Please see atached file
Comments for author File: 
Comments.pdf
Author Response
An interesting paper, addressing multi-source precipitation products across the Yellow River Basin, to develop a new integrated precipitation product.
1、In line 17- Please define VIC model as “Variable Infiltration Capacity” model.
Reply: Thank you very much for your professional advice. It’s done.
2、It is recommended that general Land Use and Land Cover information of YRB be included. Figs 11d e 11e present a very good fitting for runoff. As such results are strongly dependent of land use, it is essential to provide such information. So, please include a map of such attribute.
Reply: Thank you very much for your professional advice. It’s done.
Lines 154-157 of the revised version
According to Figure 2, the cultivated land, woodland, grassland, water, impervious and unutilized land across the YRB account for 26.27％, 13.15％, 47.54％, 1.74％, 3.17％ and 8.12％ of the total area of the basin respectively. We added the basic information map of soil type and LUCC (Figure 2).
3、Moreover, in large heterogeneous basins like the YRB the obtained fittings are surprising, and must be discussed in detail.
Reply: Thank you very much for your professional advice. It’s done.
Lines 569-577 of the revised version
Moreover, LUCC has an essential impact on the regional hydrological cycle. Many studies have confirmed that the increase in grassland and forest land leads to a decrease in runoff, while the increase in cultivated land and impervious surfaces leads to an increase in runoff [62, 63]. The runoff change in the SRYR is mainly affected by climate change but little by LUCC [64]. Therefore, the selection of LUCC has little impact on runoff simulation in the SRYR. However, for regions with large LUCC, only selecting LUCC from a single source will increase the uncertainty of hydrological simulation. LUCC from multiple sources should be considered to reduce the uncertainty of runoff simulation, such as the MYRB.
References:
[64] Gebremicael, T.G.; Mohamed, Y.A.; Betrie, G.D.; Zaag, P.; Teferi, E. Trend analysis of runoff and sediment fluxes in the Upper Blue Nile basin: A combined analysis of statistical tests, physically-based models and landuse maps. Journal of Hydrology, 2013, 482, 10.1016/j.jhydrol.2012.12.023.
[65] Nosetto, M.D., Jobbágy, E.G., Paruelo, J.M. Land-use change and water losses: the case of grassland afforestation across a soil textural gradient in central Argentina. Global Change Biology, 2010, 11(7), 1101-1117.
[66] Ni, Y.; Yu, Z.; Lv, X.; Qing, T.；Yan, D.; Zhang, Q.; Ma, L. Spatial difference analysis of the runoff evolution attribution in the Yellow River Basin. Journal of Hydrology, 2022, 612, 128149.
4、According to Figure 2, IDW interpolation is adopted, disregarding spatial dependence among stations or nodes. Please provide comments on such choice, and possible impact on the results.
Reply: Thank you very much for your professional advice. It’s done.
Lines 544-553 of the revised version
Meanwhile, to obtain the spatial weight of BMA more directly, we mapped the spatial weight by inverse distance weighted (IDW) interpolation. The advantage of IDW is that it is easy to understand and operate. The disadvantage is that it only considers the distance between the known sample point and the point to be interpolated without considering the influence of other factors and the change rule, such as landform parameters, atmospheric parameters, etc. However, several alternative interpolation methods can reduce the impact of terrain and atmosphere on interpolation, such as the Anuspline method and synchronous mapping system (SYMAP) algorithm [55, 56]. Therefore, in future research, multiple interpolation methods should be considered to reduce the impact of terrain and atmospheric parameters on BMA weight.
References：
55. Zhu, B.;Xie X.; Lu, C.; Lei, T.; Wang, Y.; Jia, K.; Yao, Y. Extensive Evaluation of a Continental-Scale High-Resolution Hydrological Model Using Remote Sensing and Ground-Based Observations. Remote Sensing, 2021, 13(7), 1247, 10.3390/rs13071247.
56. Ren, Y.; Liu, J.; Liu,; Wang, Z.; Liu,T.; Shalamzari, M.J. Effects of Climate Change on Vegetation Growth in the YellowRiver Basin from 2000 to 2019. Remote sensing, 2022, 14, 687, 10.3390/rs14030687.
Author Response File: Author Response.doc
Reviewer 4 Report
The manuscript entitled "Quantitative evaluation of runoff simulation and its driving forces based on hydrological model and multi-source precipitation fusion" is a summary of research and analysis performed to develop the spatial distribution of precipitation for a large catchment.
The aim of the work is to evaluate the Optimal Bayesian Integrated Precipitation Product performance relative to other precipitation products.The goal of the manuscript was clearly stated.
The topic is an extension of knowledge in the field of estimating the amount of precipitation in the catchment using various methods, both terrestrial and satellite. The presented conclusions are concise and appropriate, they concern the thematic scope of the manuscript.
Unfortunately, there are also shortcomings in my opinion:
1. Due to the lack of a Digital Terrain Model, it is difficult to determine the influence of topography on the results of precipitation analysis based on the presented drawings.
2. There is no information about the values of the "w" parameter in the Budyko formula for calculating evapotranspiration. However, the authors should be commended for using this old formula in the calculations, which is rarely seen nowadays.
3. The drawings presented in the manuscript are small, and because they contain a lot of information, their interpretation is difficult.
In general, the manuscript is presented concisely, it is readable with the necessary results and analysis given.
Author Response
The manuscript entitled "Quantitative evaluation of runoff simulation and its driving forces based on hydrological model and multi-source precipitation fusion" is a summary of research and analysis performed to develop the spatial distribution of precipitation for a large catchment.
The aim of the work is to evaluate the Optimal Bayesian Integrated Precipitation Product performance relative to other precipitation products.The goal of the manuscript was clearly stated.
The topic is an extension of knowledge in the field of estimating the amount of precipitation in the catchment using various methods, both terrestrial and satellite. The presented conclusions are concise and appropriate, they concern the thematic scope of the manuscript.
Unfortunately, there are also shortcomings in my opinion:
1、Due to the lack of a Digital Terrain Model, it is difficult to determine the influence of topography on the results of precipitation analysis based on the presented drawings.
Reply: Thank you very much for your professional advice. It’s done. Digital elevation model is shown in Figure 1.
2、There is no information about the values of the "w" parameter in the Budyko formula for calculating evapotranspiration. However, the authors should be commended for using this old formula in the calculations, which is rarely seen nowadays.
Reply: Thank you very much for your professional advice. It’s done.
Lines 313-315 of the revised version
In this study, the average annual runoff depth is about 168.16mm, the average annual precipitation is about 524.63mm, and the average annual potential evapotranspiration is about 729.45mm. Substituted into formula (17), the calculated w is about 1.30.
3、The drawings presented in the manuscript are small, and because they contain a lot of information, their interpretation is difficult.
Reply: Thank you very much for your professional advice. It’s done.
For the convenience of readers, we have marked the place where each picture description appears in the manuscript.
In general, the manuscript is presented concisely, it is readable with the necessary results and analysis given.
Author Response File: Author Response.doc
