Natural Disasters and Societal Safety

Natural Hazards: What are they, can they be

Predicted, and can they be Prevented?

Roy H. Gabrielsen, Professor, Department of Geosciences, University of Oslo.

Is the Problem of Natural Hazards Serious?

Natural hazards tend to be remote to us living in Norway in a well organised society

with an advanced infrastructure, our country being situated on an old and

geologically stable craton far from active geological systems like earthquake zones

and active volcanoes. There is now, though, an emerging state of unease among the

populace of Norway connected to assumed changes in climatic conditions, as

illustrated by the impact of a film like “The Wave”. The emerging concern of the

authorities is also evident (Røsjorde this volume; Thomassen this volume). We still

have to set this into an international perspective: according to the Annual Disaster

Statistical Review for 2013 published by the Centre for Research on Epidemiology

and Disasters (CRED), 96.5 million people worldwide became victims of disasters

in 2013, and 21,600 people lost their lives in disasters. These numbers are dwarfed

by the average numbers for the period 2003 – 2012, which were 216 million victims

and 106,654 deaths, respectively.

Some Characteristics of Natural Hazards

What we call “natural hazards” deals with natural processes of the Earth that have

direct, often sudden and violent, impacts on humanity. Although described as

“hazards”, it is important to realise that they are the effects of natural geological

physical (including hydrological, chemical and biological) processes linked to the

natural underlying geological dynamics of the Earth. These processes may be

associated with the enormous forces working inside our planet that are expressed

principally in the context of

plate tectonics

and its secondary processes involving

gravitation, temperature contrasts, the atmosphere and the hydrological system,

resulting in the modification of the Earth’s topography. We can thus subdivide the

types of natural hazards into those associated with geological, hydrological and

biochemical natural cycles. The hazardous effects of these processes are sometimes

exaggerated by human activities like concentration of population and construction

and infrastructure.

In our daily and scientific language, we commonly separate between (natural)

hazards

(

sensu stricto

) that characterise the effect of any (potential) natural process