2010 - World Bank - Managing Geohazards

Geohazards can result in significant loss of human life as well as cause extensive damage to infrastructure. The magnitude and frequency of geohazard events ranges from earthquakes and tsunamis to landslides and flash floods. In the most severe cases involving the low frequency but more intense geohazards like earthquakes or tsunamis, the primary concern, ex ante, is on the minimization of the potential loss of life and property, damage to infrastructure, and ensuring continuity in the functionality of public and private services. In the higher frequency, lower impact, geohazards, such as landslides, flash floods, and rockfall, proper planning remains vital, but is often overlooked in transition and developing economies. In the transport sector, proper planning for this category of geohazards can realize significant savings in construction costs, avoiding cost over-runs, repair costs and costly delays, and subsequent maintenance costs.

The principal aims in considering geohazards in the transport sector are: (i) to minimize the risk and effect of geohazards on infrastructure and on the general public; (ii) to ensure that the location decisions in respect to transport infrastructure developments are informed about geohazard risks and that appropriate precautions are identified; (iii) to assist in safeguarding public and private investment by a proper appreciation of site conditions and undertaking of necessary precautionary measures; and (iv) to restore the functionality of the transport infrastructure after unmitigated geohazard occurrences, whilst insuring, as far as feasible, that future occurrences will be mitigated.

This technical note provides a summary of the typology of geohazards, prospective mitigation measures, and current practices in managing geohazards. It also outlines some key recommendations to facilitate improved management of geohazards in the transport sector.