Geohazards play an important role in land development and have serious impacts if not considered at early planning stages. Identification of potential geohazards, assessment of their likelihood and severity is a complex task that requires integration of various information through a multi-disciplinary approach. An introductory level assessment of potential geohazards in Saudi Arabia with compilation and interpretation of publicly available data using geographic information system tools is presented in this study. The outcome is a geohazard map presenting reported and predicted geohazards including tectonics and volcanism, rock subsidence, expansive and collapsible soils and slope instability, which summarize all available information for further interpretation. The 1:2.500.000 scale composite geohazard main map provides a valuable tool for initial assessment and review in early planning stages of land development projects.
ARTICLE HISTORY
Authors have presented an approach using Multichannel Analysis of Surface Waves (MASW) to study correlations between shear wave velocity (V s ) and Standard Penetration Test N value (SPT-N) for Chennai Soils. Discusser feels that their methodology involves considerable level of approximations in various stages due to selected surface seismic method and dataset. Further clarifications should be made especially on the dataset since the main purpose of the paper is to provide a reference for future studies in the region.Authors employ a dataset developed from a surface seismic method (MASW) and SPT to obtain correlations between V s and SPT-N value. MASW introduces high levels of approximation and uncertainties for this purpose due to assumptions of the method. Effects of these assumptions related to application of surface seismic methods for SPT-N/ V s correlations and better alternatives will not be explained in detail here, a condensed discussion may be found in Gülerce (2010). However, observations on presented data, results, comparisons and performance of proposed correlations will be discussed as they indicate certain shortcomings that may be attributed to the selected method to obtain V s , lack of additional checks on V s with alternate methods and dataset characteristics.Various graphs are presented in the study for comparisons and confirmations. For example, V s computed from MASW and SPT-N profiles are plotted together in Fig. 6 to demonstrate good agreement of data for three sites. However, there is a misleading representation in this figure as shear wave velocities were not measured directly at same depths with SPT-N values for these sites. MASW can only provide V s over a certain thickness or layer of soil, which are attained during the inversion process, and plotted accordingly (e.g. as in Fig. 10). Shear wave velocities in Fig. 6 should have been plotted continuous per layers, not as single points, to prevent confusions.Capabilities of proposed correlations are tested by comparisons with other SPT-N/V s correlations from literature under Sect. 6.3. Statistically, this comparison has very limited value as it is highly biased in favor of proposed correlations since same dataset is used both to determine and check them against others. Possible causes of different results are explained after the comparisons. In fact, the main objective of local studies is to capture these differences and provide more efficient relationships for local soils.Discusser thinks that a simple utilization with local data would be a better indicator of the performance of SPT-N/V s correlations proposed by authors. Although there is a conceptual oversight in demonstration of V s Ü . Gülerce (&) Fugro Middle East,
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.