Application for Terrestrial LiDAR on Mudstone Erosion Caused by Typhoons
Round 1
Reviewer 1 Report
Review of manuscript remotesensing-593866 entitled “Application for Terrestrial LiDAR on Mudstone Erosion Caused by Typhoons”, submitted to Remote Sensing by Yeuan-Chang Cheng.
Cheng (et al.) used Terrestrial Laser Scanning (TLS) to measure surface changes in mudstone slopes and to understand the mechanism of hillslope erosion. For this, a hillslope of 180 m2 was scanned in three different dates (February 23, May 27 and August 4), corresponding to two analysis periods. The first period corresponded to a dry season (without typhoons events) and the second one to a rainfall season (with typhoons events). For each date, the point cloud obtained from the co-registration of the scans at different positions (at least six) was interpolated to obtain 10 cm x 10 cm DTMs. The main conclusions are that during the dry season the average erosion rate was 5 cm and during the rainfall season (after the typhoon events) increased to 7 cm. This increase appeared to be better correlated with the rainfall intensity than with the accumulated rainfall. At the same time, the hillslope gradient played a more important role than the rainfall intensity on the topographical change.
The topic is relevant and of interest for the readers of Remote Sensing. The results are very interesting and can contribute to a better understanding of the mechanism of hillslope erosion caused by typhoons. However, in this reviewer’s view the paper needs to be improved in some aspects before it can be accepted for publication.
General comments:
The Abstract could be improved by including a methodological sentence (e.g., study area, observation dates) and synthesizing the results. The Introduction could also be improved. Above all, I believe that the part where TLS is introduced (L. 41-44) could be extended (9 papers are referenced at once!) to bring the reader closer to this technique. I also believe that the last part (L. 45-51) should be rewritten to improve the understanding of the objectives. Regarding the Study Area, in order to follow the most commonly used scheme, I would include the Study Area as the first point of the Materials and Methods section. In the Materials and Methods a new section (at the end) should be included in order to explain the data analysis. In this sense, it would be interesting to visualize the input data for the analysis (e.g., DTMs, gradient, drainage area) for each date. Results and Discussion sections are well explained except for some small details (specific comments). The Conclusions are well suited, although I do not understand why average erosion rates (0.05 m for the dry season and 0.07 for the rainfall season) do not appear until de discussion. Finally, English writing must be improved in some aspects (the review of a native speaker can be helpful).
With all this, I believe that if the aspects discussed are addressed, the manuscript could improve considerably.
Specific comments:
First of all, I sincerely think (and it is supported by the literature) that the acronym for Terrestrial LiDAR (i.e., Terrestrial Laser Scanning) should be TLS, not TSL. In fact, TLS appeared once (L. 336) in the manuscript.
On the other hand, in many of the figures and tables (e.g., Figure 1, 3, 4 and 6 and Table 2 and 3) some results are commented in the figure or table caption itself, when they should be commented in the text.
L. 9-11: “we used TSL to detect surface changes in mudstone slopes, can help us understand”. Please review the structure of the sentence.
L. 40: “observing geomorphic”. There is a double space. Please correct.
L. 48: “180 m2” should be “180 m2”.
L. 48: Later, it is indicated that the observation period was from February 24 to August 4. Why is it not August 4 indicated here?
L. 48-51: This part should be moved to materials and methods section.
L. 58: (MOEA, 2013). Why is this reference in a different format?
Figure 1: A metric reference would be helpful.
L. 65: “Scanned photographs”, what does it mean? On the other hand, it should be indicated what refers to the image on the left and what to the one on the right.
L. 65-68: This part should be in the text and not in the figure caption.
L. 87: The special resolution (i.e., sample distance between measured points) depends on the distance. It would be convenient to detail the technical specifications of the TLS (e.g., horizontal and vertical resolution, beam diameter, etc.).
L. 89: Please reference the original factory specifications.
L. 96: “co-registered” instead of “gathered”?
L. 98: “model s”.
Table 1: “numbers of point clouds”? or “number of points (of the point cloud)”?
L. 110-114. Please, this process should be explained in more detail.
Table 2: Some typos must be corrected (e.g., placement of “Period”, “2,Meari, and Ma-on”).
L. 219: “zone and”. There is a double space. Please correct.
L. 220: “period. At”. Idem.
L. 221: “lower. However”. Idem.
L. 237: Which one is Figure 6(a)? Please specify this in the figure.
L. 246: Figure 6(b). Idem.
L. 344-346: “The results show that the average erosion rate of the target slope was 0.05 m during the dry season in 2011. After the typhoon events, the average erosion during the rainfall season increased up to 0.07 m, especially in areas more than 22-m high.” I could not find this data in the results. However, I found them in the discussion. I sincerely believe that this issue should be illustrated and commented in the results.
Comments for author File: 
Comments.pdf
Author Response
Reply and correspondence to reviewer’s comments and suggestions
General comments
Point 1: The Abstract could be improved by including a methodological sentence (e.g., study area, observation dates) and synthesizing the results.
We thank the reviewer for pointing out the comment. We accept and follow this suggestion, add the information of study site (L. 10-11), numbers of scans and the methods for error checking (L. 13-15).
Point 2: The Introduction could also be improved. Above all, I believe that the part where TLS is introduced (L. 41-44) could be extended (9 papers are referenced at once!) to bring the reader closer to this technique. I also believe that the last part (L. 45-51) should be rewritten to improve the understanding of the objectives.
We thank the reviewer for pointing out the comment. For the first part, we re-write manuscript to briefly introduce the working principle of LiDAR device (L. 44-46). Second, we point the convenience of LiDAR comparing to classic erosion methods such as erosion pins and sediment traps. We also sort the classification of research field of references mentioned there. We separate them to landslide, rockfall, beach, channel erosion, slope erosion, and add extra recent references around the main topic: slope erosion and morphology researches (L. 46-53).
Point 3: Regarding the Study Area, in order to follow the most commonly used scheme, I would include the Study Area as the first point of the Materials and Methods section. In the Materials and Methods a new section (at the end) should be included in order to explain the data analysis. In this sense, it would be interesting to visualize the input data for the analysis (e.g., DTMs, gradient, drainage area) for each date.
We thank the reviewer for pointing out the proper format of manuscript. Thus, we modify the sequence of captions as the suggestion. We remove the caption “2. Study area” and move the information of study site under the “2. Material and methods”. The following text also changes to proper sequence. E.g. “4. Result” to “3. Result”, “5. Discussion” to “4. Discussion”, and “6. Conclusion” to “5. Conclusion”.
Focus on the study area, we change the figure 1 for shadow-relief image and gradient image from the DEMs. With the grid and metric reference, the location and the size of target slope can be recognized. We also add description of the figure1 in the main text (L. 63-66). For the visualize of the study area, we change the new figure 1 with shadow-relief image, gradient map and drainage system image. We believe that the new figure could give vivid picture to readers with information of target slope.
However, we design to provide only first scanning data as the base period rather than all three scans data. It is difficult to distinguish the differences between all three periods due to the limitation of figure size. We still provide the 9 frames edition of figure 1 here to prove that the frame is too small to distinguish the differences.
(please see the image with the attachment file)
Point 4: Results and Discussion sections are well explained except for some small details (specific comments). The Conclusions are well suited, although I do not understand why average erosion rates (0.05 m for the dry season and 0.07 for the rainfall season) do not appear until de discussion.
Considering the structure of the logic of reading and revising other references, we accept the reviewer’s suggestion to give the erosion rate much earlier from the discussion to the result (L. 201-202). In addition, we give new text for explaining the following captions (L. 200-208) and figures (figure 4-6). Meanwhile, we move the Table 4 from discussion 4.1 to follow the new text part (L. 209).
Specific comments
Point 1: First of all, I sincerely think (and it is supported by the literature) that the acronym for Terrestrial LiDAR (i.e., Terrestrial Laser Scanning) should be TLS, not TSL. In fact, TLS appeared once (L. 336) in the manuscript.
We thank the reviewer for pointing out the mistake for wrong abbreviation. we correct 13 places through the manuscript. (L. 10, L. 24, L. 50, L. 57 (twice), L. 94, L. 95, L. 125, L. 364, L.370, L. 381, L. 383, L. 386, L. 400 and L. 401)
Point 2: On the other hand, in many of the figures and tables (e.g., Figure 1, 3, 4 and 6 and Table 2 and 3) some results are commented in the figure or table caption itself, when they should be commented in the text.
It has been revised and listed the sentence about the result of these table and figure.
Figure 1 (L. 63-67) We have the new figure 1 with new sentence in manuscript.
Figure 3 L. 190 , We also modify the original sentence to show the result in manuscript.
Figure 4. (L. 219-220) We add description to show the result of figure 4 in manuscript.
Figure 6. (L. 281-283) There is description for a point out the development of rills in two periods.
Table 3 (original Table 2)( L. 167-168 ) The sentences move from pervious part to here is proper place to explain the information of table 3, and emphasize 5k3 two typhoon events.
Table 4 (original table 3)(L. 201-204) We move the table 4 to the head of “3 RESULTS” caption, and add description for pointing out the erosion rate of both two periods.
Point 3: L. 9-11: “we used TSL to detect surface changes in mudstone slopes, can help us understand”. Please review the structure of the sentence.
Considering the previous suggestion for abstract, we break it to two sentences. The first sentence follows the text and adds the information of slope size. The second sentence tries to explain that we want to scan the target slope because there the erosion taken place during typhoon events (L. 9-12).
Point 4: L. 40: “observing geomorphic”. There is a double space. Please correct.
It has been revised and corrected to proper form (L. 43), and replace to “observation of geomorphic” process within a human lifetime.
Point 5: L. 48: “180 m2” should be “180 m2”
It has been revised and corrected to proper form. Also, the number has been correct to “1007” (L. 58). However, we have 9 sub-catchments, and the biggest one is the 180m2.
Point 6: L. 48: Later, it is indicated that the observation period was from February 24 to August 4. Why is it not August 4 indicated here?
We thank the reviewer for pointing out this problem. We look back to the original manuscript and find out that the original sentence only had the date of first period but lost the information of second periods. We follow reviewer’s suggestion and complete the information by adding the date information for second period: “The two observation periods were from February 24–May 27, and May 27-August 4, 2011”. (L.166-168).
Point 7: L. 48-51: This part should be moved to materials and methods section.
We thank the reviewer giving the suggestion. Considering the proper place of the scanning information, we move the sentences to the beginning of the caption “2.6 Rainfall”. The sentences show the date of observation periods and two typhoon events. It can also lead the ideal why we need to analysis the rainfall probability of three periods (L. 166-168).
Point 8: L. 58: (MOEA, 2013). Why is this reference in a different format?
We thank the reviewer for pointing out this mistake. The original sentence shows the publisher of Geological map we used but wrong referencing form. After checking the correct referencing form, we modify it to proper referencing form (L. 69).
Point 9: Figure 1: A metric reference would be helpful.
It has been revised and changed to a new figure 1 with grid and metric reference in it (L. 76).
Point 10: L. 65: “Scanned photographs”, what does it mean? On the other hand, it should be indicated what refers to the image on the left and what to the one on the right.
We thank the reviewer for pointing out this comment. We read the manuscript and find that there is lack of information referring between left and right image. Thus, we replace the figure 1 by shadow-relief image(a), gradient image(b) and drainage map(c). The shadow-relief image(a) provides morphological characteristics of target slope, such as the location of rills. The gradient image(b) shows how steep of the target slope. The drainage map provides the development of rills and drainage area. We believe the maps can satisfy to provide the position, and morphological characteristics of study area. It also responses for the requesting of visualizing.
Point 11: L. 65-68: This part should be in the text and not in the figure caption. We check the sentences of text and figure caption, and try to put the target slop’s information in the text with reasonable.
After revising the following text about the target slope, the manuscript lacked of the information for the slope size. Thus, we agree the reviewer’s suggestion, and find the proper place to fit in the slope information at L. 63-67 of main text.
Point 12: L. 87: The special resolution (i.e., sample distance between measured points) depends on the distance. It would be convenient to detail the technical specifications of the TLS (e.g., horizontal and vertical resolution, beam diameter, etc.).
We thank the reviewer for pointing out this comment. After checking the manuscript, there is lack of the technical information about the scanner. We improve the description of scanner by providing some of the detail technical specifications from original factory datasheet for scanner, such as spot size, horizontal, vertical resolution, and beam diameter (L. 94-100). We also add a new table 2 to show the error checking table and explain how we obtain the data (L. 115-128).
Point 13: L. 89: Please reference the original factory specifications.
We thank the reviewer for pointing out this comment. Following the comments No.11, we already add some technical information about the scanner (L. 103), and give reference of Leica scanstation 2 datasheet from original factory as reference No. 52 (L. 554).
Point 14: L. 96: “co-registered” instead of “gathered”?
We agree the reviewer’s suggestion and replace “gathered” to “co-registered”. Depending on the LEICA CYCLONE 7.4 user menu, we agree the reviewer’s suggestion and replace “gathered” to “co-registered”. (L. 111).
Point 15: L. 98: “model s”
It has been revised and corrected to proper form (L. 114).
Point 16: Table 1: “numbers of point clouds”? or “number of points (of the point cloud)”?
It has been revised and make sure that “Number of the points” is the correct term (L. 137, table 1).
Point 17: L. 110-114. Please, this process should be explained in more detail.
We revise the part of manuscript and re-structure the ideal of sentences. In this text (L. 130-136), we explain the reason why we need to export point cloud due to the limitation of Leica Cyclone 7.4(L. 130-133), and provide the whole processes about how we exported point cloud from Leica Cyclone 7.4, input to ArcGIS, then converted to grid format for MATLAB (L. 133-136).
Point 18: Table 2: Some typos must be corrected (e.g., placement of “Period”, “2,Meari, and Ma-on”).
It has been revised and corrected to proper form, including all the tables and figures (L. 175)(Table 3).
Point 19: L. 219: “zone and”. There is a double space. Please correct.
It has been revised and corrected to proper form (L. 265).
Point 20: L. 220: “period. At”. Idem.
It has been revised and corrected to proper form (L. 266).
Point 21: L. 221: “lower. However”. Idem.
It has been revised and corrected to proper form (L. 267).
Point 22: L. 237: Which one is Figure 6(a)? Please specify this in the figure.
It has been revised. We found that the description cannot lead the reader to find the figure 6(a). To fix this problem, we modify it with the new [Figure 6] (L. 274).
Point 23: L. 246: Figure 6(b). Idem.
It has been revised. We found that the description cannot lead the reader to find the figure 6(b). To fix this problem, we modify it with the new [Figure 6] (L. 274).
Point 24: L. 344-346: “The results show that the average erosion rate of the target slope was 0.05 m during the dry season in 2011. After the typhoon events, the average erosion during the rainfall season increased up to 0.07 m, especially in areas more than 22-m high.” I could not find this data in the results. However, I found them in the discussion. I sincerely believe that this issue should be illustrated and commented in the results.
We thank the reviewer for pointing out this comment. First, the erosion rate is an important achievement of the study result. To emphasizing this information, we move the table 4 from “4.1 Discussion” to “3. RESULT”, add sentences of manuscript for introducing erosion rates of two periods and following three captions of data analysis (L. 201-208).
Second, the “22 m high” is description where the end-up of rills on the target slope, and border of morphological changing. It shows in figure 6 with a special contour line to indicate where the 22 m high is. However, the original manuscript does not emphasize this information, even the figure 6. To improve the main text, we fix two places of manuscript. 1) We re-drew the figure 6 and emphasize 22 m high by contour line with dotted line. Now is easier to access this information. 2) We change the sentence (L. 290) “...from the slope end to a height of 22 m with a linear shape...”, directly to descript the end of rills in certain height.
Author Response File: Author Response.pdf
Reviewer 2 Report
Manuscript ID: remotesensing-593866 entitled ‘Application for Terrestrial LiDAR on mudstone erosion caused by typhoons’
General comments
The study addresses the problem of ‘high resolution’ surface differences in 60 m wide and 30 m high mudstone slope. Authors reports the results of application of the terrestrial laser scanning technique for quantitative analysis of the erosion and deposition in the Tenliao, north of Kaoshung City, Taiwan in periods with different humidity and precipitation intensity (typhoon and dry periods). The article is to general (not detailed). This research and its results are interesting, but the manuscript needs revision and could be improved. This is an interesting topic and application of the technology, but this paper requires a substantial overhaul.
First of all, the study should be better embedded in the state of the art. The issue of slope surface differences in the context of erosion and deposition processes using TLS has been widely described for more than 10 years. The Authors have overlooked in the introduction and discussion many papers that are important and set the framework for this type of research. The Authors should refer in the introduction to such studies in the context of both processes (erosion/deposition) and methodology (e.g. DoD ).
Another major concern is the lack of error assessment and propagation. The Authors must ensure that the data presented are reliable before they are presented on paper. In table 1 they give only one category (RMS by ti-point) of error. The table 1 should be completed and extended with a full list of information on the extent of data on laser rangefinder error (Leica 2007) and also errors in the registration process for each point clouds (range of error from the georeferencing in every 3 field campaign). Authors should specify RMS for individual scanner stations and reference points, like e.g. Kociuba 2017a. This information is important for estimating the uncertainty of measurement, which is the basis for making the presented results valuable. Table 1 should be verified.
The ‘state of the art’ in such analysis absolutely requires a rigorous error assessment (see suggestions to references) and propagation into the sediment balances. In my opinion, this has to be amended in order to make this study acceptable for publication if the Authors decided to stick to their primary objective stated in the introduction.
Suggested references:
Barbarella M., Fiani M. (2013). Monitoring of large landslides by Terrestrial Laser Scanning techniques: Field data collection and processing. Eur. J. Remote Sens., 46: 126-151.
Barbarella M., Fiani M., Lugli A., (2017). Uncertainty in Terrestrial Laser Scanner Surveys of Landslides. - Remote Sens., 9(2): 113.
Huising E.J., Gomes Pereira L.M. (1998). Errors and accuracy estimates of laser data acquired by various laser scanning systems for topographic applications. - ISPRS Journal of Photogrammetry & Remote Sensing 53: 245–261.
Kociuba, W., 2017a. Analysis of geomorphic changes and quantification of sediment budgets of a small Arctic valley with the application of repeat TLS surveys, Zeitschrift für Geomorphologie 61, Suppl. 2, 105-120.
Kociuba, W., 2017b. Assessment of sediment sources throughout the proglacial area of a small Arctic catchment based on high-resolution digital elevation models, Geomorphology 287, 73-89.
Lane, S.N., Westaway, R.M., Murray Hicks, D. (2003). Estimation of erosion and deposition volumes in a large, gravel-bed, braided river using synoptic remote sensing. - Earth Surf. Process. Landforms 28: 249–271.
Leica (2007). Leica ScanStation 2 Datasheet. https://w3.leica-geosystems.com/downloads123/hds/hds/ScanStation/brochures-datasheet/Leica_ScanStation%202_datasheet_en.pdf
Mazzotti S., Adams, J. (2005). Rates and uncertainties on seismic moment and deformation in eastern Canada. - Journal of Geophysical Research 110: B09301.
Schwendel A.C., Fuller I.C., Death R.G. (2012). Assessing DEM interpolation methods for effective representation of upland stream morphology for rapid appraisal of bed stability. River Res. Applic. 28: 567–584
Wheaton J.M., Brasington J., Darby S.E., Sear D.A. (2010). Accounting for uncertainty in DEMs from repeat topographic surveys: improved sediment budgets. Earth Surface Processes and Landforms 35: 136–156.
Summarizing review, this paper is unsuitable for publication in its current form. Authors should rewrite some parts of the work and improve the English. English native speaker proofreading would be advisable. After these shortcomings have been remedied, the manuscript should be sent for second round review before being printed in Remote-Sensing. I hope my suggestions help the Authors to more fully exploit their data and produce a potentially highly relevant paper.
Author Response
Reply and correspondence to reviewer’s comments and suggestions
Point 1: First of all, the study should be better embedded in the state of the art. The issue of slope surface differences in the context of erosion and deposition processes using TLS has been widely described for more than 10 years. The Authors have overlooked in the introduction and discussion many papers that are important and set the framework for this type of research. The Authors should refer in the introduction to such studies in the context of both processes (erosion/deposition) and methodology (e.g. DoD ).
We thank the reviewer for pointing out the comment. For the first part, we re-write manuscript to briefly introduce the working principle and the conveniences of LiDAR device (L. 44-47). Second, we sort the classification of research field of references mentioned there. We separate them to landslide, rockfall, beach erosion, channel erosion, slope erosion, and add recent references (L. 48-53). For the introducing of the methodology of error assessment, we increase the manuscript to mention it in “2.4 DTM processing” (L. 114-128).
Point 2: Another major concern is the lack of error assessment and propagation. The Authors must ensure that the data presented are reliable before they are presented on paper. In table 1 they give only one category (RMS by ti-point) of error. The table 1 should be completed and extended with a full list of information on the extent of data on laser rangefinder error (Leica 2007) and also errors in the registration process for each point clouds (range of error from the georeferencing in every 3 field campaign). Authors should specify RMS for individual scanner stations and reference points, like e.g. Kociuba 2017a. This information is important for estimating the uncertainty of measurement, which is the basis for making the presented results valuable. Table 1 should be verified.
We thank the reviewer pointing out the issue. In fact, we already concern the error assessment of the survey processes. First, we set a test for verifying the abilities of scanner. We fixed the scanner at same position and operated to scan same artificial models. After checking the testing result, it shows the more than 96% scan points would locate almost same position (changing less than ±6mm). When operating TLS during field survey, we use TLS only during sunny days to avoid the interference that the laser been absorbed by rainfall. For avoiding the error from human mistake, all three scans followed the same stand operating processes.
For reducing error propagation, we use the permanent target points (TP method) to estimate the error of co-registered processes. We set 10 bench marks around the target slope, and obtain their local grid position by Leica total station TPS1101. The error of their position was around 0.001m. These points joined into other temporary ti-points for ortho-calibrated scan data by Leica Cyclone program, and obtained the first calibration error less than 0.6 cm in all control points. In addition, we used the local grid position of benchmarks to check the errors producing by two grid systems (TLS and local position system). The RMS of all three scans was less than 0.005 m. The DEMs of difference (DOD) of each two periods are 0.00336 m (first periods) and 0.00297 m (second periods) (L. 114-128) (Table 2). We believe that the result of morphological changing obtained by scans is much large than the estimating error, and the quality of scanning data can support the following analysis.
Point 3: The ‘state of the art’ in such analysis absolutely requires a rigorous error assessment (see suggestions to references) and propagation into the sediment balances. In my opinion, this has to be amended in order to make this study acceptable for publication if the Authors decided to stick to their primary objective stated in the introduction.
We agree the reviewer’s point. Following the suggestion references like Kociuba, 2017a, and 2017b, Lane et al.(2003) and Barbarell et al.(2017). They mention that the error can take place from the abilities of TLS and co-registered whit different point cloud. They also provide several methods to check the error of scanning point. A common point of these references is that they usually use RMS for checking if the error of point out of reasonable level, and DEMs of difference (DoD) to make sure the data quality is acceptable. We also find that our data calibrating procedure was very similar to Kociuba (2017a), e.g. the permanent target point method, Leica Cyclone software and Leica TLS device. Thus, we refer it and add the error estimating table including ti-point absolute error, error vector and RMS. We also add the DOD checking result on the table 2. All we put effect to show that the error assessment and propagation has been consideration during data producing process. The related error assessments that we have listed on previous responses.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Review of manuscript remotesensing-593866-v2 entitled “Application for Terrestrial LiDAR on mudstone erosion caused by typhoons”, submitted to Remote Sensing by Yeuan-Chang Cheng.
In general, all issues raised in the previous round of review have been satisfied. However, the paper needs to be improved in some minor aspects before it can be accepted for publication. Because of this, this reviewer proposes a minor review.
General comments:
The Abstract and Introduction have improved considerably. However, the Materials and Methods could still be improved (see specific comments). The Results, Discussion and Conclusions have also improved in the aspects commented in the previous round. Finally, I reiterate that English writing must be improved in some aspects (the review of a native speaker can be helpful).
Specific comments:
L. 48, 51, 52, 69, 87 and more: The brackets must be separated from the previous word by a space.
L. 77-79. Again, this explanation should be in the main text and not in the figure caption.
Figure 2. This figure (location of the study area) should be first and then include the Figure 1 (study area map).
Table 2. It should be “Number of points”.
L. 138-142. Please, this process should be explained in more detail.
L. 167: “respectively(Table 3)”. A space is needed.
Table 2: Some typos must be corrected (e.g., placement of “Period”, “Second05/27”)
L. 185-188. Again, this explanation should be in the main text and not in the figure caption.
L. 209-212. Again, this explanation should be in the main text and not in the figure caption.
Table 4. “Frist period”. Please correct.
L. 215-218. Again, this explanation should be in the main text and not in the figure caption.
L. 277-280. Again, this explanation should be in the main text and not in the figure caption.
Comments for author File: Comments.pdf
Author Response
Point 1: L. 48, 51, 52, 69, 87 and more: The brackets must be separated from the previous word by a space.
It has been revised and corrected to proper form, including other 4 places.
(L. 48, 51, 52, 66, 84, 103, 123, 194 and 201.)
Point 2: L. 77-79. Again, this explanation should be in the main text and not in the figure caption.
We thank the reviewer for pointing out the comment. We move the explanation from figure 1 into manuscript, which can lead readers to understand the idea we want to show with these three images: the relief, gradient and drainage density of target slope. (L.73-76)
Point 3: Figure 2. This figure (location of the study area) should be first and then include the Figure 1 (study area map).
We thank the reviewer for pointing out the proper format of manuscript. We accept the suggestion. Thus, we modify the geological information of manuscript and “location of the study area” by moving forward to follow the caption “2.1. Location” (L. 61-71). The introduction of target slope moves toward to location of the study area.
However, we think the study area map should keep individual figure. The map provides the slope information of dimension, gradient, relief and drainages. They need certain space to show the image. Thus, we believe that it is better to keep the location of the study area map and study area map individual.
Point 4: Table 2. It should be “Number of points”.
It has been revised and corrected to “Number of points” (L.133).
Point 5: L. 138-142. Please, this process should be explained in more detail.
We thank the reviewer for pointing out the proper format of manuscript. We found the logic of original manuscript was not clear. We modify this part of main text by focus on the how the slope relief affected the point distribution, and it may lead to cause the area with low density, even blank (L. 134-137).
Point 6: L. 167: “respectively(Table 3)”. A space is needed.
It has been revised and corrected to proper form (L. 162).
Point 7: Table 2: Some typos must be corrected (e.g., placement of “Period”, “Second05/27”)
There you mention the typos should be Table 3. It has been revised and corrected to proper form by adjusting the column space (L. 170).
Point 8: L. 185-188. Again, this explanation should be in the main text and not in the figure caption.
We thank the reviewer for giving this suggestion. After revising the explanation of figure 3 in manuscript, we found that the description already appearance in main text (L. 182& 188). Thus, we decide to remove the explanation which following the caption.
Point 9: L. 209-212. Again, this explanation should be in the main text and not in the figure caption.
We thank the reviewer for giving this suggestion. We move the explanation from table 4 to main text, which can lead readers to understand the idea we want to show with the table: the erosion facts in first and second periods (L. 196-198).
Point 10: Table 4. “Frist period”. Please correct.
We thank the reviewer for pointing out this comment. We read the manuscript and find that there is lack of information of these two periods. Thus, we modify the caption with the date of first and second periods. In addition, we also adjust the first column to “Period”, and following with the first and second period. We believe that the adjustment can help readers more easily to catch up the ideas of these two periods and their erosion fact (L. 203).
Point 11: L. 215-218. Again, this explanation should be in the main text and not in the figure caption.
We thank the reviewer for giving this suggestion. After revising the explanation of figure 4 in manuscript, we found that the description already appearance in main text (L. 211-216 & 225-228). Thus, we decide to remove the explanation which following the caption.
Point 12: 277-280. Again, this explanation should be in the main text and not in the figure caption.
We thank the reviewer for giving this suggestion. After revising the explanation of figure 4 in manuscript, we found that the description already appearance in main text (L. 270-275 & 280-285). Thus, we decide to remove the explanation which following the caption.
Author Response File: Author Response.pdf
Reviewer 2 Report
Manuscript ID: remotesensing-593866 entitled ‘Application for Terrestrial LiDAR on mudstone erosion caused by typhoons’
General comments
The study addresses the problem of ‘high resolution’ surface differences in 60 m wide and 30 m high mudstone slope. Authors reports the results of application of the terrestrial laser scanning technique for quantitative analysis of the erosion and deposition in the Tenliao, north of Kaoshung City, Taiwan in periods with different humidity and precipitation intensity (typhoon and dry periods). This is an interesting topic and application of high resolution TLS measurement methods and comparison of digital terrain models. This is the second time I have had the opportunity to evaluate this text. Many aspects and suggestions have been taken into account suggested after first review.
The Authors supplemented the information about the uncertainty of measurement and the range of errors at each stage of the process of TLS survey and DTMs and DoD calculations. Unfortunately, the Authors have not avoided a few more errors. These are mainly disadvantages of editorial or linguistic nature: typographical errors or imprecise text formulations. List of detailed comments below:
L 110: ‘2 million’ instead of ‘2 milliom’
L 115: maybe it should sounds: In the first step, the quality of DEMs must be validated.
L 127: ‘DoD’ instead of ‘DOD’ also in caption of last column in the table 2(line 155).
The caption for Table 1 and the data in the second line are not fully understood. 1) Does the caption refer to the parameters of the final merged 3D model in each campaign or discretionary 3 individual scans. 2) What do the values described as the number of points mean? They are usually given as total numbers of points, e.g. 50 Million of points [M pt]. For model validation, the density of points used to generate the grid cell (range and average) is also important, expressed as the number of points per square meter [pt m-2 or simply pt/m-2]. It would be worthwhile to verify the caption and complete the data in the table 1.
Table 2. Verify the data in the last column to match the corresponding description in lines 127-128, e.g. as in the example below should be better (example in *.docx version). The measurement dates are limited to the following periods.
L 127: ‘DEMs’ instead of ‘Dems’
Summarizing review, this paper is almost suitable for publication in its current form. The text is clearly and well written but contains a few typos and some sentences are not precise. The authors have not taken up my suggestion to have the text reviewed by an English native speaker, so I repeat this suggestion. English native speaker proofreading would be advisable. After these sparse shortcomings have been remedied, the manuscript should be printed in Remote-Sensing.
Comments for author File: Comments.pdf
Author Response
Point 1: L 110: ‘2 million’ instead of ‘2 milliom
It has been revised and corrected to 2 million (L. 106).
Point 2: L 115: maybe it should sounds: In the first step, the quality of DEMs must be validated.
We thank the reviewer for giving this suggestion. After revising the main text, we accept the suggestion and replace this sentence (L. 111).
Point 3: L 127: ‘DoD’ instead of ‘DOD’ also in caption of last column in the table 2(line 155).
It has been revised and corrected to proper form (L. 123 & 150).
Point 4: The caption for Table 1 and the data in the second line are not fully understood. 1) Does the caption refer to the parameters of the final merged 3D model in each campaign or discretionary 3 individualscans. 2) What do the values described as the number of points mean? They are usually given as total numbers of points, e.g. 50 Million of points [M pt]. For model validation, the density of points used to generate the grid cell (range and average) is also important, expressed as the number of points per square meter [pt m-2 or simply pt/m-2]. It would be worthwhile to verify the caption and complete the data in the table 1.
We thank the reviewer for giving this comment. After revising the manuscript, we found that our mistake would mis-leading the readers. Thus, we accept this suggestion, and modify the Table 1 (L. 133). We change the text flow direction for clearer format and add the new column to provide the information of points density with pt/m2. The caption of Table has also been changed to proper form. We believe that that reader can obtain more information of our scan results.
Point 5: Table 2. Verify the data in the last column to match the corresponding description in lines 127-128, e.g. as in the example below should be better (example in *.docx version). The measurement dates are limited to the following periods.
We thank the reviewer for giving this mistake. It has been revised and corrected to proper form (L. 150).
Point 6: L 127: ‘DEMs’ instead of ‘Dems’.
It has been revised and corrected to proper form, including other 10 places.
(L. 109, 110, 111, 123, 126, 135, 147, 153, 155, 157, and 193.)
Author Response File: Author Response.pdf
