Natural Hazards Lecture Notes:
Firstly, we need to know what a “Geohazard” is:
It is an Earth process that upon interaction with human activity causes loss of life and (or) property.
By “Earth process” we mean a natural event that occurs within the lithosphere/crust, hydrosphere (e.g. weather system) or atmosphere.
Why is it important that we study Geohazards?
Because they are a hazard to the human population and (or) infrastructure
If human lives were not threatened or endangered then the process would not be classed as a “hazard” and it would not be so vital that we understand the processes involved.
The hazard assessment branch of science, that provides a wide range of jobs, has become very popular over the last few years. With wild weather seemly becoming more common globally the race is on to find ways to reduce the impact of hazardous events on the human population.
Why is the human element so critical, or, why is it becoming more important to understand these events?
The Earth’s population is increasing and therefore, as existing cities etc become full and people search for new space to live in, more and more enter into areas that are prone to hazards.
For example, today around 50% of the 6 billion inhabitants on Earth live in cities. Current trends suggest that by 2025 there will be 8 billion people on Earth and 66% of them will be living in cities.
Of all the cities, 40% of them lie on the coast and therefore are prone to severe storm and tsunami damage.
There are many other examples:
The sides of volcanoes have very fertile soils, so farmers plant their crops or graze their livestock closer and closer to the volcanic vent in order to increase their revenue
People build houses further up into mountains in areas where landslides occur.
“Before and After” photographs from Phuket, Thailand, of the 2004 Boxing Day (26th of December) tsunami.
We need to...