Flood Risk Assessment of the Wadi Nu’man Basin, Mecca, Saudi Arabia (During the Period, 1988–2019) Based on the Integration of Geomatics and Hydraulic Modeling: A Case Study

Round 1

Reviewer 1 Report

The content is interesting and well exposed; however, I would like to know how and where you found the data related to velocity and depth of the water, because in many cases flood surveys are not so accurated (at least here in Italy).

Two minor suggestions to help the reader:

1) to translate also in the western calendar the date of the recent flood of Wadi Nu'man (25.2.1440)

2) to better link tables and images to the text to facilitate the comprehension.

Author Response

Reply to1^stReviewer

 We thank the reviewer for submitting the notes, which are met as follows: -

1) to translate also in the western calendar the date of the recent flood of Wadi Nu'man (25.2.1440)

-The main manuscript has been amended.

2) to better link tables and images to the text to facilitate the comprehension.

The main manuscript has been amended

Reviewer 2 Report

Review of " Flood Risk Assessment of Wadi Nu’man Basin, Mecca, Saudi Arabia (during the Period 1988-2019) based on the Integration of Geomatics and Hydraulic Modeling " by Drs. Abdelkarim and Gaber

 

Summary:

This study assesses the risks of floods in Wad Nu’man basin during 1988-2019 by using the integration of multiple methods and models such as HEC-HMS, HEC-RES, SCS, GIS, RS. The authors show the maps of the rainfall, geological, hydrological characteristics of the basin to analyze the risk of flooding. Finally, the authors recommend several plans to reduce future flooding risk.

 

General Comments:

This manuscript looks like a report to the decision-makers, and it is not written for the scientific community. As a reader, I want to learn the scientific problems defined by the author and the solutions to these problems. Unfortunately, I did not find it. Moreover, the authors did not provide any steps to show how the models are calibrated and verified.

 

Details of the comments:

1. There are many figures, and most of them are redundant. None of them show the reliability of their models (e.g., watershed-scale runoff simulation vs. observations).

2. L11-18: This is simply copied from L79-87 from the introduction. This is not allowed in a scientific paper. The abstract should be concise and point out the scientific problems the authors want to address.

3. L50-76: The authors provide a literature review on the methods for flood risk modeling in Figure 1. Why these methods are chosen, and what are their advantages and disadvantages?

4. L77: The figure is not accurate. For example, GIS-MCE in the figure becomes GIS-MCDA in the text; Elshamy method in the figure may refer to the Al Shami method in the text.

5. L61: Hierarchical Analysis Method should have an abbreviation of HAM, not AHP.

6. L95-119: The general readers do not care much about the history of Wadi Nu’man.

7. Fig3 repeats Fig 2

8. Lin 154: subscripts are needed in the units of m3/m and all the following units.

9. It looks like Tyson Polygons are used in Fig 7 (it should be explicitly introduced). However, I see the line at 40.12E is wrong.

10. The captions for all figures are short and do not provide enough information. For example, what type of isoline is shown in Fig8 (annual rainfall, seasonal rainfall, or runoff?). Also, if Tyson Polygons are used, it should not have such smooth contour lines.

11. Since the authors already have models, it would be nice to test all the recommendations given in section 6 to show how these plans quantitatively reduce the flood risk.

 

Author Response

Reply to2^ndReviewer

 We thank the reviewer for submitting the notes, which are met as follows: -

General Comments:

1- This manuscript looks like a report to the decision-makers, and it is not written for the scientific community. As a reader, I want to learn the scientific problems defined by the author and the solutions to these problems. Unfortunately, I did not find it. Moreover, the authors did not provide any steps to show how the models are calibrated and verified.

The manuscript is written in a clear and balanced scientific methodology and methodology. Over the past 30 years, perhaps the most prominent of these challenges are urban expansions at the expense of natural valleys and increasing environmental changes and loss of ecological and ecological balance and increase groundwater rise and high soil salinity and increase pollution and exposure to urban the city to flood risk, which requires the use of sophisticated modern techniques that determine the negative effects and help to mitigate the risk of flooding of the city, which is aimed at the rear in the schematic side applied to the decision-makers, without sailing focus in the framework of my non-beneficial. As for the solutions to this problem, the study presented a practical and realistic practical solutions to mitigate the risks of flooding Wadi Noman, the details of which are under the title of measures and protection proposed by Seoul Wadi Nu'man, which are practical scenarios to address the risks of flooding of Wadi Nu'man represented by constructing a dam 6 meters high and developing the area. Located in the part before the diversion dam with the preservation of a channel width of 200 m and the expansion of the channel in the section immediately after the end of the dam (the ruling part) to the width of 200 m, and this alternative aims to distribute the behavior of Wadi Noman on a rectangular channel south of the dam established in the ruling section, width 200 meter The hydraulic study of this solution has shown that the depth of the water in front of the dam will be less than 3 m. Located at the end of the diversion dam to be at least 200 m wide. This requires the work of rock cutting up long to 1225 meters, and the volume of work of rock cutting will be about 2.2 million cubic meters, as well as refining the slope of the canal in this area to increase the speed of discharge. As for showing the calibration of model's verification was added in the revised manuscript.

Details of the comments:

There are many figures, and most of them are redundant. None of them show the reliability of their models (e.g., watershed-scale runoff simulation vs. observations). The forms in the manuscript are expressive and balanced, and the lack of one or two forms of verification of the model does not reduce the fact that there is a shortage, and this part has already been emphasized in the revised manuscript. L11-18: This is simply copied from L79-87 from the introduction. This is not allowed in a scientific paper. The abstract should be concise and point out the scientific problems the authors want to address. The summary has been rewritten in the revised manuscript. L50-76: The authors provide a literature review on the methods for flood risk modeling in Figure 1. Why these methods are chosen, and what are their advantages and disadvantages? The existence of a comparative approach to the methods of determining flood risk modeling, at the introduction of the research important and useful work and gives a background and value of the current work, the aim is to review the methods used and suitability for modeling the risk of floods in urban areas, and highlight the best for this research, has been added part in the revised manuscript highlights The advantages and disadvantages of these methods are simplified and without getting into the details. L77: The figure is not accurate. For example, GIS-MCE in the figure becomes GIS-MCDA in the text; Elshamy method in the figure may refer to the Al Shami method in the text. Reply: The revised manuscript has been amended. L61: Hierarchical Analysis Method should have an abbreviation of HAM, not AHP. (AHP) is the abbreviation (Analytic Hierarchy Process), it is already a hierarchical analysis method that determines the weights in the method of multi-criteria analysis, and you can see many references such as (Ljubomir, G, et al, 2017, Olga, P, et al, 2018, Kazakis, N, et al, 2015).

 

Ljubomir, G.; Dragan, P.; Zoran, B.; Siniša, D. Application of GIS-Interval Rough AHP Methodology for Flood Hazard Mapping in Urban Areas, Water 2017, 9, 360, https://0-doi-org.brum.beds.ac.uk/10.3390/w9060360.

Kazakis, N.; Kougias, I.; Patsialis, T. Assessment of flood hazard areas at a regional scale using an index-based approach and analytical hierarchy process: Application in Rhodope–Evros region Greece. Sci. Total Environ. 2015, 538, 555–563., https://0-doi-org.brum.beds.ac.uk/10.1016/j.scitotenv.2015.08.055

Olga, P.; Nerantzis, K.; Ioannis, K.; Thomas, P.; Nicolaos, T.; Konstantinos, V. Assessing Flood Hazard at River Basin Scale with an Index-Based Approach: The Case of Mouriki, Greece. Geosciences. 2018, 8, 50, https://0-doi-org.brum.beds.ac.uk/10.3390/geosciences8020050.

L95-119: The general readers do not care much about the history of Wadi Nu’man. The revised manuscript has been amended Fig3 repeats Fig 2 The revised manuscript has been amended Lin 154: subscripts are needed in the units of m3/m and all the following units. The revised manuscript has been amended It looks like Tyson Polygons are used in Fig 7 (it should be explicitly introduced). However, I see the line at 40.12E is wrong. The revised manuscript has been amended The captions for all figures are short and do not provide enough information. For example, what type of isoline is shown in Fig8 (annual rainfall, seasonal rainfall, or runoff?). Also, if Tyson Polygons are used, it should not have such smooth contour lines.

The revised manuscript has been amended

Since the authors already have models, it would be nice to test all the recommendations given in section 6 to show how these plans quantitatively reduce the flood risk. The proposals and solutions presented in the manuscript were subjected to public discussion and were discussed with the decision makers at the Holy City of Makkah, which is based on the implementation and planning of the floods. The quantitative impact of these plans on their ability to reduce flood risk in quantitative terms was also measured.

Reviewer 3 Report

The manuscript titled “Flood Risk Assessment of Wadi Nu’man Basin, Mecca, Saudi Arabia (during the Period 1988-2019) based on the Integration of Geomatics and Hydraulic Modeling” Abdelkarim and Gaber, investigates flood risk by means of hydrological and hydraulic models. The topic is interesting to the journal and, in particular, it would find readers interested in hydrological areas. For the most part, the manuscript is very well-written and structured but, in several sections, you need to provide more details. Therefore, there are several aspects that need to be addressed before the manuscript can be accepted for publication. I attach my comments above the pdf.

Comments for author File: Comments.pdf

Author Response

Reply the Third Reviewer

It has been modified about 67 Note in main manuscript

 

"Please see the attachment." 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The paper has some improvement. However, it still fails to answer the big question: what is the scientific question and how to solve this question.

In the reply letter, the authors try to show the big question is the urbanization and its environmental impacts. This is a big question and it is impossible to solve this big question in one paper. A proper scientific question is to find a niche (e.g., the difficulty of quantifying one aspect of risk, or climate uncertainty) and try to solve it in this paper.

The overarching goal of model simulation is to provide results before making the final decision, thus avoiding potential disaster and find the optimal solutions. Therefore, quantifying the risk of authors' recommendation at end of the paper should be the highlight of the paper.

Author Response

First, the parts to be improved are improved as follows:

Summary. Results. Conclusions.

Second: The following has been modified:

Methodology and methods of study. Research design format.

These amendments can be found in the revised version of the study