1 - Natural Hazards and Urban Risks

At the lecture today, some of the points raised were:
- how to define "urban risks"? - the concentration of people, industry and infrastructure in urban areas combined with potential natural hazards happening in those areas creates risk
- vulnerability and risk as purely human considerations. Otherwise hazards don't matter, life will continue
- more than half of the world population now lives in cities (first time ever)
- after disasters, people tend to keep rebuilding on the very same site
- some old ways of adapting life to deal with hazards were very clever, but can get forgotten or are incompatible with urban life (e.g. migrating between 2 villages in Indonesia, to avoid volcanic hazards)
- current trend is to protect from hazards - very expensive and technologically driven
- dilemma facing towns: allow development on risky land, or play it safe and lose potential revenue?

The "weighting task" was to assign the relative importance to Europe of 10 different types of natural hazards. Our group of 6 agreed that they weren't all equal, that some of the hazards seemed more important than others. My own way of judging them was to recall which kinds of hazards I had heard about in the news over the last few years. The ones that came to mind included: forest fires in Greece, a big earthquake in Italy, heat waves in central Europe (summer 2010), and numerous river floods in central Europe. We only had a short time to quantify all 10 hazards, so we ended up averaging everyone's individual assessment. Floods ended up being the highest, which seemed right to me. When we switched with another group, we found out that they had somewhat different estimates than us, since they considered mainly immediate risks to urban areas, while we considered general risks over all time scales. The biggest difference was that we ended up ranking "drought" quite high, as it's a long-term concern, while the other group gave it 0%, since a drought wouldn't pose any immediate threat to a city.

Here is a table of the results:

Hazard	Me	Our group	Other group
droughts	5	13	0
extreme temp's	15	10	13,3
earthquakes	15	13	3,33
floods	25	19	16,6
forest fires	15	14	8,8
landslides	5	8	15,5
storms/cyclones	5	10	16,6
storm surge	5	7	13,3
tsunami	5	3	6,6
volcanic eruptions	5	3	5,5
Total	100	100	100

Considering a similar assessment for my hometown (Vancouver, Canada), there would definitely be some different concerns compared with a general assessment for all of Europe. The most dangerous natural hazard there would be earthquakes, as Vancouver is located on the "Ring of Fire" around the Pacific Ocean. There's always talk of when the Big One will hit, just like in San Francisco. In school we regularly had earthquake drills in addition to fire drills. It seems like the city mostly addresses this risk through building codes and public awareness and education, for example encouraging households to maintain a stock of drinking water, canned food, flashlights, etc. Another important natural hazard would be forest fires, as the region is heavily forested and can get very dry in the summertime; also landslides, as the area is also mountainous and some suburbs are built on the slopes, and landslides have occured after heavy rains. Windstorms are a more recent and unexpected concern, following a devastating storm a few years ago. A big problem with these is that trees get knocked over and take down power lines. Tsunamis don't seem to be too important since the city is protected by Vancouver Island. Flooding may be a concern as the city is on the mouth of the Fraser River, and one large suburb (Richmond) is largely below sea level.

Here is what I think the results would look like:

Hazard	Weight
droughts	3
extreme temp's	3
earthquakes	25
floods	10
forest fires	20
landslides	15
storms/cyclones	15
storm surge	3
tsunami	3
volcanic eruptions	3
Total	100