Rockfall Hazard Rating System(s) in Saudi Arabia – A Review

Adnan M Aqeel

doi:10.5539/jgg.v10n4p1

Abstract

Slope instability along highways in mountainous areas is not only a major hazard for lives and passing vehicles but also may hinder traffic for long period and thus create significant economic loss. The most common type of slope instability failures in such areas is rockfalls. Many qualitative rockfall hazard rating systems (RHRSs) have been developed across the world. However, the Middle East almost lacks to such systems. For instance, in Saudi Arabia, which has the largest economy in the region, only one system of rockfall hazard rating system (RHRS-SA) has been developed up to now. This paper aimed to critically review this system. Some drawbacks were found in the RHRS-SA. However, the main disadvantage was that the final rating score of risk is not consistent with risk definition. In sum, the remarkable findings of this review can be accounted either for any future modifications for the RHRS-SA or to develop a new rockfall hazard rating system but for a specific area(s) in Saudi Arabia.

Highlights

Rockfall is a significant sporadic and unpredictable natural hazard that usually affects highways and roads which are cut in mountainous areas (Bunce, Cruden, & Morgenstern, 1997; Hungr, Evans, & Hazzard, 1999)
3.2 Evaluation of the rockfall hazard rating systems (RHRSs)-SA the Rockfall Hazard Rating System of Saudi Arabia (RHRS-SA) is the first attempt of developing a rockfall hazard rating system in Saudi Arabia, it has critical drawbacks to which this research is concerning and aiming
Underestimation for the resulting risk will occur. 3.2.2 Classifying Hazard Degrees and Risk Levels One other problem which can be noticed in the RHRS-SA is that the number of hazard categories does not match and is not consistent with the number of the consequences risk categories which may cause miscalculation and misinterpretation for the final calculated risk level

Summary

Introduction

Rockfall is a significant sporadic and unpredictable natural hazard that usually affects highways and roads which are cut in mountainous areas (Bunce, Cruden, & Morgenstern, 1997; Hungr, Evans, & Hazzard, 1999). Rockfall is one of the most common slope instability types in the world (Badger & Lowell, 1992; Keefer, 2002; Guzzetti, Reichenbach, Cardinali, Ardizzone, & Galli, 2003; Ferrari, Giani, & Apuani, 2013). Rockfall can be defined as a type of small scale landslide in which a single rock or boulder or a small group of independently moving rocks become dislodged from an exposed rock slope face and moves downward under the action of gravity (Varnes, 1978; Ansari, Ahmed, Singh, & Ghalayani, 2015). Rockfall could not have the same level of economic risks as large scale slope failures, the number of people whom are killed by rockfall tends to be the same number of killed people by other types of rock slope instability (Hoek, 2006). Rockfalls can cause a disaster as that one happened in Al-Dhafir village in Sana’a, Yemen in 2008 where the entire village was destroyed and resulting in loss of life of 65 persons (Aqeel, Maerz, & Anderson, 2014)

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Conclusion