INTRODUCTION: CONCEPT OF A NATURAL EVENT AND A HAZARD Objectives: 1. Students will describe aspects of natural events that pose threats to humans and impacts of these events on people, in writing and through discussion. Use scientific vocabulary to summarize research about natural hazards. 3. Students will be able to distinguish between an naturalevent, natural hazard and disaster. 4. Classify the different types of natural hazards.
DISTINGUSIHING BETWEEN A NATURAL EVENT, A HAZARD AND DISASTERS • Natural Events are any atmospheric, earth or water related occurrence. Natural Events are responsible for the occurrence of natural hazards. • Natural Hazards are extreme weather and /or other conditions caused by nature. Some examples include volcanoes, earthquakes etc. It is an unpredictable or uncontrollable natural event of unusual magnitude that poses danger or threat to human life ,property and economic assets. • Disasters are natural hazards that has a profound impact on local people or places either in terms of loss of life or injuries ,property damages or environmental impact.
WHY SHOULD WE BE CONCERNED ABOUT NATURAL HAZARDS? • In every person’s lifetime , at least one natural hazard will likely to have some impact on their life . On average ,about 150,000 people are killed worldwide by natural hazards each year. • Unfortunately, the economic cost of natural hazards is increasing dramatically. • Globally , losses from natural hazards are increasing partially due to the exponential increase in human population. This unprecedented number of people has reduced resource availability and forced people to live in marginal areas where natural hazards occur more frequently and often with greater severity . • In many developed countries ,loss of life is low but economic costs are extremely high. • In many developing countries ,loss of life tends to be very high while economic costs are usually lower.
RISE IN INCIDENCE AND SEVERTIY OF NATURAL HAZARDS • Climatic changes , attributed to global warming , have been important in changing sea water temperatures and the pattern of precipitation . • Temperatures have reached a level where bleaching of coral occurs. • Bleaching causes the destruction of corals and therefore the protective barriers to coastal areas. • These coastal areas are vulnerable to flooding and storm surges during hurricanes. Without protection , the coastal areas are also prone to flooding given the rise in general sea level. • The rise in sea water temperatures have resulted in the El Nino phenomena. • These phenomena have resulted in altering increased precipitation and floods. • The impact of hurricanes has been directly linked to increase in ocean water temperatures.
TECHNOLOGICAL HAZARDS A technological hazard is any application of practical or mechanical sciences to industry or commerce capable of harming persons, property or the environment. Examples : improper use or portable generators or heating devices can release deadly carbon monoxide. Oil spills and fires caused by dysfunctional equipment or improper use. De icing agents or melting compounds can pollute waterways. A geomorphological hazards may be defined as those events or processes, natural or man induced that cause a change in earth surface characteristics detrimental to man and his activities.
CLASSIFYING HAZARDS Classification of natural hazards by geophysical processes.