Review of 'Integrating tsunami risk assessments in development planning: lessons from Western India'

Dear Editor,

the article with title Integrating tsunami risk assessments in development planning: lessons from Western India by the authors Richard Bradley, Serge Guillas, Garima Jain, Cassidy Johnson, Teja Malladi, Julia Wesely deserves a rejection in the present form for different reasons, which are explained in the general and detailed comments below.

General comments:

Firstly, the highlighting “aspects of the management of these uncertainties problems” and the making “some suggestions as to how they might be resolved” are very ambitious. If the authors do not comprehend properly the scientific meaning of the hazard issues they cannot pretend to make any suggestion to resolve uncertainty problems and to “promote and suggest optimal policies”. Please see terminology and definitions in “Tsunami glossary, 2019” (https://unesdoc.unesco.org/ark:/48223/pf0000188226) by Intergovernmental Oceanographic Commission, in particular at page 17 for Tsunami Hazard and at page 34 for Tsunami Forecast. Scientists do not think “they are able to predict the occurrence of a harmful event”. Geophysicists provide probability of occurrence and in some cases forecasts, which are different from predictions. Prediction has a distinct meaning and is not used for catastrophic natural events, especially for tsunamis. For these reasons the schema in Figure 1 starts on the wrong basis of knowledge and shows a wrong “ideal picture”. Modelling is used to produce the best hazard assessment and the evaluation of the uncertainties are part of the hazard analysis, two separate blocks in Figure 1 indicate that the authors have no clear idea about the tsunami hazard assessments.

Secondly, the links and the interactions of the different component in the schema are not discussed adequately in the paper. They do not explain the meaning of the consequential flow of the blocks linked by the arrows and it is not clear the meaning of “Implementation Modelling” in the “Policy Identification” part. The schema should be re-written using: a) the appropriate terminology, b) a consistent explanation and c) a clear view of the scientific aspects that the authors considered in their paper. The first block should be simple named “Hazard Assessment”. “Exposure State Characterization” also should be discussed in connection with the “Policy Choice”. Moreover, it is not clear what the authors intend by “Implementation Modelling” and it should be well explained, because it is a very general part. Only at the end of the paper the authors refer to “possible to model people’s responses to policy initiatives and draw on this information in assessing different policy options”, but they don’t say how. They do not explain from “Welfare Evaluation” and the entire schema is disconnected from the discussion.

Also, the paper does not include the line numbering and it is difficult to indicate the comments related to each statement or paragraph during the reviewing process. However, this reviewer is also available to read a re-submitted version with the  modifications.

Other detailed comments:

At page 6 the authors wrote “The upshot of all of this is that, although precise predictions of the frequency and severity of earthquakes are generated by current seismic models, there is disagreement in the scientific community about the degree to which these predictions can be trusted, even for regions for which there is considerable seismic data." May be the authors intend “scenarios”, if it is the case the authors are making a big misunderstanding between scenario, forecast and prediction.

At page 13 the authors wrote “If policy making is to be sensitive to implementation uncertainties the image of the ‘unified planning agent’ assumed in standard planning approaches must be dispensed with”. However, they should know that in an “ideal” situation there is the need of some experts able to train both municipality level workers and average people, having as a main task the explanation of the tsunami hazard assessments of the regions and the uncertainties in the tsunami analysis. Policy makers and authorities should receive scientific tools to understand tsunami hazards, the related uncertainties and the probabilistic estimates and to manage tsunami risk in order to find the best planning solutions. Also, both policy makers and authorities should receive the proper training on how to communicate the hazard to the citizens, in order to avoid illusive wrong ideas, certain simplistic beliefs and not realistic/possible predictions. My comment is that the “ideal situation” is based on the best understanding of the tsunamis hazard and risk, then the good knowledge of the potential catastrophic events will certainly indicate the best solutions at regional scale for both the safety of a community and the developments of the social/economic activities. The examples the authors mentioned in section 4 show that ignoring the importance of hazard uncertianties may increase tsunami risks.