Social Vulnerability to Natural Hazards in Namibia: A District-Based Analysis

Round 1

Reviewer 1 Report

Overall assessment:

With its scope on the social vulnerability of people and their exposure to natural hazards, the paper addresses an important issue to better understand socio-economic dynamics and its linkage to the possible impact of climate change affecting the livelihood of people, and therewith their vulnerability, in resource-driven environments that needs proper attention by both social and natural scientists, resources managers and development workers and planners.

Based on the presented literature review I am convinced that the paper raises a methodologically interesting and relevant topic referring to various approaches usually utilized to assess social and natural systems interactions, therefore, the paper could be a useful contribution to better understand the drivers, mechanisms and pattern of social vulnerability in relation to natural hazards in Namibia. Even though the paper refers to methodologically and scientifically interesting aspects, I am not entirely convinced by the overall scientific representation of the given results and their interpretation (also related to the utilized data set).

To my opinion, some of the results, in particular regarding the vulnerability of people in certain areas and to certain natural hazards are overstated taking the presented data and methods into account (see examples in the comments). I would recommend that the authors improve the underlying data basis and also include causal relationships in the discussions. For example, it is known that an area which provides natural resources (e.g. access to water) that support settling and agricultural expansion has a higher social vulnerability due to population density but is also more exposed to floods, whilst a sparsely populated area may be characterized by a highly adapted population living with extremely limited resources. The comparison of such diverse areas in the context of vulnerability and exposure to hazards may also consider aspects like amongst others national history, traditions, migration, law enforcement, planning, development etc. which could be taken up in the discussion. From my point of view, these are different aspects with a high complexity which need different methodological approaches rather than a simplified index approach.

In addition, the paper has some notable formal weaknesses and redundancy. The manuscript does not follow a consistent structure which makes it difficult to fully understand whether it is rather focusing on the method or the finding for Namibia. For example, a very good background is given in the introduction part, followed by the description of the data/methods and a short section on results. On the other side, the discussion and conclusion section barely refers to the interpretation of the result (e.g. provide background on diversity in Namibia or other driving or limiting factors, stressors, legislation), but rather discusses the method, limits of the data and the approach, presents further results and provides explanation for the drivers and pattern by referring to findings of other studies. It provides very helpful and interesting references but limits the scientific value of the author’s findings since it rather confirms other researcher's, thus known  results. Also, the paper refers to districts as administrative units, but the population dynamics are driven by the history including ethnic environments, traditions/historic development, migration etc, thus the reference to districts might be overstated. It would be rather interesting if certain ethnical or economic communities are stronger affected by social vulnerability and natural hazards which could be added.

To support my above discussion, I would like to give some more specific comments on general and formal issues:

General comments (selected):

• As highlighted by the authors, the data basis is somewhat critically. While the socio-economic data refer to the year 2016, while all natural hazards are referring to a very limited time period and causes are presumptive. For example, the authors used death livestock as an expression of drought. While in the season 2018/19 when a severe drought hit the country and caused a high mortality on livestock and wild animals, this is also related to other aspects such as overstocking following a period of good rains, limits in fodder production for the stock etc.. In other years, mortality in livestock might also be influenced by diseases, even in wet years. Thus, contextual information may provide plausible additional information. Also, integrating human mortality and schools affected and people displaced should only be used when normalized by using climate conditions or hydrological information. Many papers are published on floods in the Cuvelai, Kunene, Kavango and Zambezi basins which might provide some additional data sources to provide information on flood patterns and impacts.
• Definition of natural hazards is vague and should be clarified (as provided for the social indicators). For example, the authors refer to wildfires, but the savanna ecosystem in northern Namibia, southern Angola, southern Zambia and north-west Botswana is a fire-driven environment, for both environmental conservation and agricultural management purposes. However, the majority of fires are man-made and controlled (as stated in the study area), thus it is difficult to speak about natural hazards or wildfires. This should be clarified.
• The selection of the 7 indicators is supported by firm evidence which is not provided (p.5,180) and more background on what basis it was weighted (p5/6).
• The description of the study area provides a good overview, however, I suggest to include some background on i) the high inner and interannual spatio-temporal variability of climate patterns and extremes as well as some basic meteorological background since a gradient might not be supportive in explaining droughts (and floods). Also, floods in the northern part of the country are normally originated in the upper catchments in Angola and part of a annual pattern. Revise causes of floods (pg3, 126-129.
• Pg 5, l: 179: the critical assessment should be explained, and reference should be provided given that the data set is sparse.
• In the results presentation, it should be stated that the least vulnerable districts are also the economic, social and political centers with the capitol Windhoek and some smaller, but relevant towns like Rehoboth and Okahandja in Khomas and Walvis Bay/Swakopmund in Erongo. Also, there are quite a number of towns in the northern part affecting the impact of the indicators in some districts. This should be discussed.
• Pg7, 228 ‘are zero’ refers to the respective year of interest.
• Pg 8, 230. This statement can be misunderstood since different years (drought in 2018/19) are referred too. The conditions for the respective years should be addressed to provide evidence for this statement.
• P8, 233: flood risk is higher in this area and related to the major rivers along and crossing the borders, originated in Angola. Most of these rivers are flood pulse systems and it is a known fact, published in numerous publications.
• Pg 9, 266: Explain multiple populations
• Section 4.1 is widely redundant since it refers to the methodological approach with some repetitions
  • Pg10, 271: It is a known fact and even considered in national programmes.
  • Pg10, 272: I would expect that the drivers for these differences are discussed. Otherwise some statements are only descriptive.
  • Pg 10, 280ff: this is a lot of background information and extends the introduction. The relevance for the own findings are rather vaguely described.
  • Pg 10, 296ff: Information on the methodological approach is redundant.
  • Pg10, 310, 313: what means relatively? To what?
• Pg12, 371: stressors should be explained
• Pg12, 380: very generalized conclusions which might be supported by concrete numbers. Also, why is the number of food insecure people in Erongo and Karas remain low?
• Possible effects of climate change impacts on the various indicators are not discussed, despite its mentioning in the Abstract.

Formalities (selected):

• There are some statements repeated, e.g. Namibia is the driest country in Sub-Sahara Africa (p1, 2, 3 and 9) and many blanks are missing. The manuscript should be checked in this regard.
• Remove the keyword floods. The paper does not particularly provide any scientific information on floods.
• Source and definition/rationale of data for the natural hazards’ indicators should be presented as presented for the social indicator.
• Wildfire average burned area periods are inconsistent in tables 1 (2007-2017) and 1 (Appendix (2012-216)
• Pg. 5, table 1: i) household income might be provided in US dollars for comparison with other countries but also taking the high volatility of the currency into account, ii) mentioned the year in the table description

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

1. Interesting study that will inform leaders and citizens of Namibia for policy and decision making toward reducing vulnerability to natural hazards. 
2. The spatial analysis was well-done.
3. For the statistical analysis, I would like to have seen a Principle Components Analysis or a similar method for selecting variables for the three categories. You justified your selection of "convenience" using the literature as well as your experience and knowledge; however, it reduces the scientific objectivity of your analysis and results. Nonetheless, your approach was explained well, and it's appropriate. 
4. Explain better how you determined the "weights".
5. In more recent times, the hazards literature has shifted from "vulnerability" to "resiliency", so if you expand and/or revise this research as data becomes available, you may want to emphasize "resiliency" and how that might be attained in these administrative regions.
6. Proofread carefully. (a) Often you have not properly used singular and plural (nouns and verbs). Recheck for agreement. (b) Use "can" and "may" properly. (c) take out spaces around numbers, such as around the % signs and "mm." (d) Table 1, under the abbreviations, I think you want >60 not <60. (e) Several sentence need to be rewritten for clarification--at 151, 156, 215-16, 229, 278 (f) at 247 take out one of "the", (g) 281 spell out IPCC, (h) at 299 at (ii) rewrite that sentence for clarity, (i) use which instead of what at 315, (j) at 339-340 rewrite that sentence for clarity--use "conducted" not "confronted". (k) use more parends at "e.g.'s and i.e.'s" within body of text. 
7. Use the past tense on your variables from Sections 2.2, 3 and 4 and on. You have already performed the study, so you are in the past!! Revise all your verbs!!
8. Consider switching the order of sections 4.1 and 4.2. I thought that the discussion on Population Vulnerability Characteristics (4.2) flowed better right after 3.3 Vulnerability Assessment.   
9. Overall, well-done!! I enjoyed reading your study. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

For me, it has been a very interesting manuscript about the relationship between social vulnerability and natural hazards in Namibia.

Despite of the few comments included in attached file, I hava only two main comments about the manuscript. First, I am not sure about the title of the manuscript, and the main reason is the absence of the assessment scale into the title. You have made a macro-scale assessment that could be very usefull for natural risk management in Namibia or another undeveloped countries with scarze dada sources. But the title suggest a clear relationship between social vulnerability and natural hazards, and It is not easy to establish from the results of the present study, since as the authors themselves indicate, the local or micro-scale variability could not be determined by the absence of information. So, I suggest to include the term "macro-scale" or "regional" into de title.

Second, I feel like the manuscript needs a "Conclusion" section, where you make a final resume of the key topics of the manuscript.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

The manuscript entitled “Social Vulnerability Coincides with a High Risk from Natural Hazards in Namibia”, by A. Kapuka & T. Hlásny, presents an interesting work.

In general, the manuscript should be acceptable for publication but some serious problems must be repaired prior to publication. It needs some significant improvement. Some suggestions are as follows:

1. Please use different terms in the “Title” and the “Keywords”.
2. Please follow the journal author instructions. It would be useful for the reader to follow the classical text structure (i.e. Introduction-methodology-results-discussion-conclusions). I suggest to separate the section “4. Discussion and Conclusions”.
3. It would be useful to be described the aim of this paper.
4. The English language usage should be checked by a fluent English speaker. It is suggested to the authors to take the assistance of someone with English as mother tongue.
5. I propose to the authors to be more specific, explanatory and simplified in order to be easily understandable from the readers.
6. In all maps you must put coordinates.
7. You could enrich the scientific literature.
8. Please justify convincingly why this manuscript (method, thematology etc) connected with Sustainability’s content and scope. Perhaps the using more references from this journal would be helpful.
9. The authors could make a discussion about the relationship between the vulnerability and hazard maps using the following publications:

- Bathrellos, G.D., Skilodimou, H.D., Chousianitis, K., Youssef, A.M., Pradhan, B. (2017): Suitability estimation for urban development using multi-hazard assessment map. Sci Total Environ, 575: 119 – 134.

- Skilodimou, H.D., Bathrellos, G.D., Chousianitis, K., Youssef, A.M., Pradhan, Β. (2019): Multi-hazard assessment modeling via multi-criteria analysis and GIS: A case study. Environ Earth Sci, 78 (2): 47.

10. Please be careful with the spaces between the words.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Feedback to the revised version.

In my opinion, the manuscript was notably improved by the authors taking the recommendations of various reviewers into account. I am convinced that the manuscript (except for a few minor aspects) presents a study fulfilling the quality standards of the journal and provides a valid input to the scientific discussion on vulnerability in developing countries, particularly in Namibia. With taking the recommendations into considerations, the authors clearly present the limitations of their study and, by this, leave it to the informed reader to put the findings in the context without overstating individual findings themselves. I also like the change of the title which is much clearer and better describes the intention of the study.

I only have a few additional recommendations to better represent the country-related information:

Pg 4, 143ff: I appreciate that this information is provided. However, I suggest to revise it and provide a source. Also, correct the name of the Owambo ethnic group and correct the statement on the influence of the apartheid (for a quick overview check even wikipedia). E.g. the Owambo group (50%) were barely affected by apartheid and relocations (e.g. red line). Please revise this section.

pg4, 155: other sources of income--> tourism, mining, agriculture, constrcution

pg4, 156: the statement 'poverty is extreme...' should be referenced

pg6, 192: the season with the severs drought was 2018/19 whilst 2019/20 was fairly wet

With the historical context on ethnic groups, and particularly the Owambo people, the exposure to vulnerability might also be reflected in the context of a population which purposely settled and stayed in a region providing access to natural resources, and despite climate extremes and others to which they have adapted.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

The manuscript entitled “Social Vulnerability to Natural Hazards in Namibia: A district-based analysis”, by A. Kapuka & T. Hlásny, presents an improved and good work.

The manuscript could be acceptable for publication in the present form.

Author Response

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Author Response File: Author Response.pdf