Mapping Groundwater Potential Zones Using Analytical Hierarchical Process and Multicriteria Evaluation in the Central Eastern Desert, Egypt
Round 1
Reviewer 1 Report
Mapping Groundwater Potential Zones using Analytical Hierarchical Process and Multicriteria Evaluation in the Central Eastern Desert, Egypt
... after abstract analysis ...
- lines 11-12 ... what kind of phrase is this: ”To distribute population density around the Nile to other uninhabited desert areas of Egypt.”?;
the point seems to be forced, to finish without reason a phrase just started;
- lines 12-14 ... this construction
”This study aims to identify groundwater potential zones (GWPZs) in the water-scarce desert between the Qina and Safga-Bir Queh regions to construct groundwater wells to attract and support people's demand for water, food, and urban development.”
seems to be partially in accordance with this (lines 20-23)
”Validation has been done between the observed Total Dissolved Solid (TDS) with the calculated GWPZs, indicating that the highest and lowest TDS concentrations of most aquifers are correlated with low to very low and high to very high aquifer potential, respectively.”
... being with one eye to the title;
is your intention one to built just on the qualitative approach/direction?; in this case, you must proceed in consequence in the title, because, in this stage, the title condemns you to a double quantitative and qualitative analysis to satisfy ”demand for water ... and urban development”; the potential and the demand of a zone is quantitative and qualitative in this direction;
all the specialists know that the problem of the mineralisation is the most delicate in the desert underground water reserves, but, for building and developing human habitats the quantitative one is, also, at least similar as importance as;
before the Introduction the TDS is everywhere less in the title (qualitative specification) .......;
let's see the text body; maybe only the abstract needs to be changed;
- in the first part of Introduction several reference titles need to sustain general informations about Egipt and it desert water resources;
- which is the data source for the components from Figure 1?; the same problem for figures 2-4, 6, 8 (DEM source) etc.;
are these all your measurements?;
you, always, must specify the source after the title;
- lines 107 etc. - I hope, this is a joke: do you use https://weather-and-climate.com/ to characterise, in scientific way, the climate of studied area?;
don't you have national or regional statistics in this direction?;
- where are the lines (overlapped on a map) and the orientation of the profiles from Figure 3?;
- how did you get from geology to elements from Figure 4, without presenting an 1D & 2D cartographic and text analysis of aquifer layers and experimental/useful drills/bores?;
are these layers present or is just a hypothesis based on rock types?;
when these aquifers are the main components of your topics, do you consider that these elements need to be consulted by reader from the literature?;
why TDS before of groundwater volumes/reserves?;
- break the structure between 172 and 195 lines in several parts;
you will reduce the effort of reader;
- you have several problems with flow chart from the 5th figure:
geomorphology is a science; remove-it and will remain the other two geomorpho' components;
rainfall is, first of all, a meteorological/climatic element and after a hydrological one in water balance;
for the establishment of groundwater deposits you need more precipitation and infiltration than DRAINAGE TO THE SURFACE OF THE TERRAIN; this parameter is so secondary;
- another joke: with an average rainfall amount of 5.7 mm/year (line 221) you speak about Groundwater Potential Zones?;
in this case, only ”juvenile” or other historical category of groundwaters can be considered, if these are not mineralised and if these are present in your sedimentary structure, after experimental drilling verification;
- in Figure 7, why do you speak about ”dissolved geological areas” and not about rocks permeability?;
- where have you seen this type of chromatic range for the altitude on the hypsometric maps?;
normally, a rage of green-yellow-brown is used;
- lines 282-283 - in the situation of 5.7 mm/year precipitation is hilarious to make that affirmation;
better remove;
- sorry; Figure 12 is not a drainage density map; is only a map of streams (drainage morphological line);
- lines 332-333 - this 651 km/km2 will remain in history, when thw hydrologists speak about average range values of water courses/hydrographic network density of 1-4 km/km2;
yes, the drainage density (gutter, gully and torrential stream) is more than permanent hydrographic network density, but ... take care;
I repeat, for the establishment of groundwater deposits you need more precipitation and infiltration than drainage to the surface of the terrain;
- sorry, your Figure 14a is not Geomorphology; it represents morphological structures;
- your GWPZs mapping (started from 362 line) needs to be revised, according the up-metioned observations, insisting on groundwater deposits and experimental boring;
- also, you must change the title, insisting on the quantitative side of the problem, if you intend to propose this water use in human habitats extending;
the same aspect regarding the validation (is better to use hydrogeological maps with piezometric levels and calculated volumes etc.);
the problem of the mineralisation is the most delicate, in the desert underground water reserves, for building and developing human habitats; an easy increase of this parameter reduces at cvasi-zero the possibility of groundwater use; all structure starting from 397 line up to 489 line is non-sense, if the water use not refers to brine use or other similar therapeutic/recreational types;
just in Figure 21 you start to arrive in the hydrogeological domain;
- conclusions need to be modified according the title and text body specific.
Author Response
The authors would like to thank the knowledgeable reviewer for their insightful comments on the manuscript's content. We appreciate the opportunity to revise the manuscript to improve its quality and readability. All the suggestions were well taken, and the authors did their best to improve the manuscript structurally and grammatically. In addition, the manuscript has been reorganized for a better understanding of the readers.
Comment: ... after abstract analysis ...
- lines 11-12 ... what kind of phrase is this: ”To distribute population density around the Nile to other uninhabited desert areas of Egypt.”?;
the point seems to be forced, to finish without reason a phrase just started;
Response: Thanks for the comments. The sentence has been modified to make it clearer and more readable.
Comment: - lines 12-14 ... this construction
”This study aims to identify groundwater potential zones (GWPZs) in the water-scarce desert between the Qina and Safga-Bir Queh regions to construct groundwater wells to attract and support people's demand for water, food, and urban development.”
seems to be partially in accordance with this (lines 20-23)
”Validation has been done between the observed Total Dissolved Solid (TDS) with the calculated GWPZs, indicating that the highest and lowest TDS concentrations of most aquifers are correlated with low to very low and high to very high aquifer potential, respectively.”
Response: The TDS was collected from boreholes in the study area (Table 5 and 6; sections 3.2.1 and 3.2.2). We know that low TDS in groundwater indicates high recharge and vice versa. This study demonstrates that GWPZs with high to very high potential recharge are located near boreholes with low TDS, which validates our findings.
Comment: ... being with one eye to the title;
is your intention one to built just on the qualitative approach/direction?; in this case, you must proceed in consequence in the title, because, in this stage, the title condemns you to a double quantitative and qualitative analysis to satisfy ”demand for water ... and urban development”; the potential and the demand of a zone is quantitative and qualitative in this direction;
all the specialists know that the problem of the mineralisation is the most delicate in the desert underground water reserves, but, for building and developing human habitats the quantitative one is, also, at least similar as importance as;
before the Introduction the TDS is everywhere less in the title (qualitative specification) .......;
let's see the text body; maybe only the abstract needs to be changed;
Response: The primary goal of this research is to identify and provide more potential recharge zones for the construction of productive groundwater wells to meet human needs. Furthermore, we pay attention to the qualitative aspect of these potential recharge zones; thus, we validate our GWPZs with high to very high potential recharge with TDS collected from nearby boreholes.
It concludes that the mapped GWPZs can provide qualitative groundwater wells.
Comment: - in the first part of Introduction several reference titles need to sustain general informations about Egipt and it desert water resources;
Response: A paragraph has been added in the introduction section, which describes the general information of Egypt and its desert water resources.
Comment: - which is the data source for the components from Figure 1?; the same problem for figures 2-4, 6, 8 (DEM source) etc.;
are these all your measurements?;
you, always, must specify the source after the title;
Response: Figure 1 was created using a LANDSAT 8 image and GIS (ArcGIS software) with bands 7, 4, and 2. The references to figures 2, 3, and 4 have been added at the recommendation of the valued reviewer. Figures 6 and 8 were created using a GIS and a digital elevation model (DEM) (ArcGIS software).
The satellite images (data) collected and used for this study are detailed in the text (Sections 2.2 and 2.3).
Comment: - lines 107 etc. - I hope, this is a joke: do you use https://weather-and-climate.com/ to characterise, in scientific way, the climate of studied area?;
don't you have national or regional statistics in this direction?;
Response: Thanks for the valuable comment. As per the suggestion, the correction has been done in the text.
Comment: - where are the lines (overlapped on a map) and the orientation of the profiles from Figure 3?;
Response: Thank for the comments. The sourced information does not trace the line profile. It just mentioned the area.
Comment: - how did you get from geology to elements from Figure 4, without presenting an 1D & 2D cartographic and text analysis of aquifer layers and experimental/useful drills/bores?;
are these layers present or is just a hypothesis based on rock types?;
when these aquifers are the main components of your topics, do you consider that these elements need to be consulted by reader from the literature?;
why TDS before of groundwater volumes/reserves?;
Response: We want to inform the reviewer that we didn't receive this comment in the best possible way. However, based on our understanding, the answer is as follows:
The water depth and TDS mentioned in this study were gathered from previous research conducted by researchers in this field. We've already included all of the relevant information in the text, along with citations.
Comment: - break the structure between 172 and 195 lines in several parts; you will reduce the effort of reader;
Response: The paragraph between line no. 172 to 195 has been broken into several parts to be easily readable.
Comment: - you have several problems with flow chart from the 5th figure: geomorphology is a science; remove-it and will remain the other two geomorpho' components;
rainfall is, first of all, a meteorological/climatic element and after a hydrological one in water balance;
for the establishment of groundwater deposits you need more precipitation and infiltration than DRAINAGE TO THE SURFACE OF THE TERRAIN; this parameter is so secondary;
Response: Figure 5 has been corrected as per the suggestion of the reviewer. The box containing “geomorphology” has been removed from the figure.
Comment: - another joke: with an average rainfall amount of 5.7 mm/year (line 221) you speak about Groundwater Potential Zones?;
in this case, only ”juvenile” or other historical category of groundwaters can be considered, if these are not mineralised and if these are present in your sedimentary structure, after experimental drilling verification;
Response: Rainfall is minimal, so it has the lowest weight and rank (Tables 3, 7-8) in parameter matching for both techniques used. Egypt, particularly the Eastern Desert, is considered an arid zone with little precipitation. The latter is thought to be critical for shallow aquifers in desert areas. If rainfall increases, it will follow the same downward and upward trend as shown in Figure 6, and the aquifer potentiality zonation will be the same geographically.
Comment: - in Figure 7, why do you speak about ”dissolved geological areas” and not about rocks permeability?;
Response: Dissolve item in GIS reduce the layers in Figure 2 into five zones based on contribution to aquifer potentiality (1 means low permeability – 5 means high permeability).
Comment: - where have you seen this type of chromatic range for the altitude on the hypsometric maps?;
normally, a rage of green-yellow-brown is used;
Response: Indeed, a green-yellow-brown color scheme is commonly used for altitude. However, no protocol allows users to select only these predefined colors to display altitude range. Another reason is that Figure B represents elevation divided into five ranges, so the authors used these color combinations to make it more appealing and easier to understand.
Comment: - lines 282-283 - in the situation of 5.7 mm/year precipitation is hilarious to make that affirmation;
better remove;
Response: Thank you for your comment. The reviewer's assessment is shared by the authors. As a result, as shown in the tables (Tables 3, 7-8), rainfall has the lowest rank and weight for both applied techniques.
However, the low rainfall had an impact on the shallow aquifer, which was the point of interest.
Comment: - sorry; Figure 12 is not a drainage density map; is only a map of streams (drainage morphological line);
Response: According to the definition, “Drainage density, defined as channel length per unit watershed area (km km-2), reveals the number of channels in a watershed (Horton, R. E. (1932)).” This drainage map was prepared using SRTM-DEM 90 m resolution data in ArcGIS using the spatial analyst tool, and the method of stream ordering is according to Strahler number (Strahler A.N., 1964).
Comment: - lines 332-333 - this 651 km/km2 will remain in history, when thw hydrologists speak about average range values of water courses/hydrographic network density of 1-4 km/km2; yes, the drainage density (gutter, gully and torrential stream) is more than permanent hydrographic network density, but ... take care; I repeat, for the establishment of groundwater deposits you need more precipitation and infiltration than drainage to the surface of the terrain;
Response: Indeed, for the establishment of groundwater deposits, we need more precipitation and infiltration than drainage to the terrain's surface. But the little rainfall may change to heavy rain but with the same trend of increase and decrease as shown in Figure 6. Hence, it is essential to introduce the rainfall map. Based on previous evidence, similar projects used rainfall parameters even if they were low. It is easy for us to remove the rainfall map; alternatively, we already represent the rainfall parameter with the lowest weight and rank.
It has been done in the manuscript in red color.
Comment: - sorry, your Figure 14a is not Geomorphology; it represents morphological structures;
Response: It has been corrected in the text.
Comment: - your GWPZs mapping (started from 362 line) needs to be revised, according the up-metioned observations, insisting on groundwater deposits and experimental boring;
Response: It has been incorporated in the manuscript.
Comment: - also, you must change the title, insisting on the quantitative side of the problem, if you intend to propose this water use in human habitats extending;
the same aspect regarding the validation (is better to use hydrogeological maps with piezometric levels and calculated volumes etc.);
the problem of the mineralisation is the most delicate, in the desert underground water reserves, for building and developing human habitats; an easy increase of this parameter reduces at cvasi-zero the possibility of groundwater use; all structure starting from 397 line up to 489 line is non-sense, if the water use not refers to brine use or other similar therapeutic/recreational types; just in Figure 21 you start to arrive in the hydrogeological domain;
Response: Thank you for your feedback. We want to inform the reviewer that we are not interested in aquifer volumes or discharge. This paper aims to identify promising areas for aquifer potentiality, i.e. groundwater with suitable TDS ranges that can be used for drinking or irrigation.
The suggestion to change the paper title is unnecessary because the paper focuses on suitable high groundwater recharge and low TDS ranges rather than aquifer groundwater volumes.
Comment: - conclusions need to be modified according the title and text body specific.
Response: The authors tried hard to make changes to the conclusions that were consistent with the title and text of the manuscript. The entire conclusion has been formatted and changed.
Reviewer 2 Report
I believe that the work presented for review is interesting and has a practical value. However, I consider the preparation of the manuscript as careless. It gives the impression that authors direct the work to themselves rather than to external readers. Some of the sentences are incomprehensible, i.e. the first sentence of the abstract. Moreover, authors use a lot of abbreviations, some of them are not explained, i.e. “TDS” occurs 32 times in the text and is explained only once in the abstract. This is sloppy. English and fluency of the text must be corrected by a native speaker.
In my opinion the presented reclassification methodology is unclear and cannot be repeated in other studies. It seems very subjective. I.e., in case of rainfall (figure 6) authors state that rainfalls in the range of 0.83-1.0 mm have a very low potentiality rank. On what data were you basing while making such an assumption? Why did you choose such a specific range? Why not 0.83- 2.00 mm? Do we get the same results for this range as well? This remark applies to all other parameters. Moreover, authors normally use five classes, however, when this is impossible they start using four (figure 14). What is the repeatability of such analyzes?
Minor remarks:
Source for figure 1 and 2 is missing
Figure 4: why bars on the left are from “down to up “, while on the right “up to down”?
Paragraph 2.2: What important information is carried by such a sequence of characters: “LC08_L1TP_174042_20151115_20170402_01_T1)” or “RTM1N26E033V3”?
Author Response
Comment: I believe that the work presented for review is interesting and has a practical value. However, I consider the preparation of the manuscript as careless. It gives the impression that authors direct the work to themselves rather than to external readers. Some of the sentences are incomprehensible, i.e. the first sentence of the abstract. Moreover, authors use a lot of abbreviations, some of them are not explained, i.e. “TDS” occurs 32 times in the text and is explained only once in the abstract. This is sloppy. English and fluency of the text must be corrected by a native speaker.
Response: First and foremost, the authors would like to thank the knowledgeable reviewer for their insightful comments on the manuscript's content. We appreciate the opportunity to revise the manuscript to improve its quality and readability. All the suggestions were well taken, and the authors did their best to improve the manuscript structurally and grammatically. With the assistance of other colleagues (few native English speakers), the language of the entire text has been improved. In addition, the manuscript has been reorganized for a better understanding of the readers.
Comment: In my opinion the presented reclassification methodology is unclear and cannot be repeated in other studies. It seems very subjective. I.e., in case of rainfall (figure 6) authors state that rainfalls in the range of 0.83-1.0 mm have a very low potentiality rank. On what data were you basing while making such an assumption? Why did you choose such a specific range? Why not 0.83- 2.00 mm? Do we get the same results for this range as well?
Response: Yes, the rainfall influences shallow aquifer potentiality. If the precipitation increases, the recharge aquifer will increase. If the rainfall declines, the aquifer recharge will decrease. The rainfall parameters influence aquifer potentiality, as mentioned before.
Comment: This remark applies to all other parameters.
Response:
1- The geology contribution to aquifer potentiality is based on the permeability and effective porosity of the sediment. The highest aquifer potentiality was found in sandstone (high permeability), while the lowest was found in compact hard rocks (low permeability). The rest of the geology of the sediment ranged between the two previous values.
2- Due to changes in lineament permeability, the number of rock fractures (lineaments) increases with high aquifer potentiality and decreases with low aquifer potentiality.
3- In addition, drainage density and geomorphology contribute differently to aquifer potentiality.
4- All of the above-mentioned points were written in the manuscript.
Comment: Moreover, authors normally use five classes, however, when this is impossible they start using four (figure 14). What is the repeatability of such analyzes?
Response: We get the same results if we use four classes, five classes, nine classes, ten classes, less than ten classes, or more than ten classes. GIS was used to calculate the distribution parameters.
Comment: Source for figure 1 and 2 is missing
Response: Thanks for this comment. Figure 1 was created using a LANDSAT 8 image and GIS (ArcGIS software) with bands 7, 4, and 2. The references to figures 2, 3, and 4 have been added at the recommendation of the valued reviewer.
Comment: Figure 4: why bars on the left are from “down to up “, while on the right “up to down”?
Response: The bars on the left are arranged from "down to up" because the water depth was measured from the land's surface and then below.
On the right, "up to down" due to the aquifer's TDS concentration as a standard draw illustration.
Comment: Paragraph 2.2: What important information is carried by such a sequence of characters: “LC08_L1TP_174042_20151115_20170402_01_T1)” or “RTM1N26E033V3”?
Response: These characters contain the basic information (code of the images) about the satellite images used in this study. The information is as follows:
-LC08_L1TP: Landsat 8
-174: Path (WRS Path: defined nominal Landsat satellite track (path). (orbital)
-42: Row (WRS-defined nominal Landsat satellite row. (orbital)
-20151115: date acquired (15/11/2015)
-20170402: Date Product Generated of satellite image 8 (02/04/2017)
-T1: Collection category. T1 = Tier 1 is the highest available quality and processing level.
Round 2
Reviewer 1 Report
-
Reviewer 2 Report
The text of the work has been corrected. I have no more comments.
