Tag Archives: natural hazard

Area Content Alert: 44, 2 (June 2012)

Cover image for Vol. 44 Issue 2The latest issue of Area (Volume 44, Issue 2, pages 134–268, June 2012) is available on Wiley Online Library.

Click past the break for a full list of articles in this issue.

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Content Alert: New Articles (27th January 2012)

These Early View articles are now available on Wiley Online Library.

Original Articles

The paradigm of structural engineering approaches for river flood risk reduction in Norway
Ilan Kelman and Trude Rauken
Article first published online: 23 JAN 2012 | DOI: 10.1111/j.1475-4762.2011.01074.x

A physical hazard and human problem

Hurricane Irene viewed from space, August 2011

I-Hsien Porter

This year’s hurricane season is drawing to a close, with the east coast of the USA receiving its fair share of damage. Hurricane Irene, in late August, caused the deaths of 40 people and led President Barack Obama to approve a $1.5bn relief fund. The following week, Tropical Storm Lee caused one death and left 16,000 people without power.

In a recent paper in Geography Compass, Jason Senkbeil and others argue that the USA’s hurricane problem is caused by a complex, interconnected series of physical and human processes.

Much of the damage that resulted from Hurricane Irene was not caused by the high winds on their own. Storm surges, tornadoes, heavy rain and flooding are all associated with hurricanes and tropical storms. The physical processes that cause harm to human lives, buildings and infrastructure are a complex mix. They include the main, or primary, event (in this case, the hurricane) and the resulting secondary hazards (such as heavy rain causing flooding, then leading to a landslide, for example).

We wouldn’t be particularly concerned about all this, however, if there weren’t also people living in the path of the hurricane. There may be many complex processes that draw people to live in particular places. Different people are affected in different ways and also have different capacities to respond to a hazard. For example, ordering residents to evacuate from an area is not particularly productive if those people have no mode of transport with which they can do so. In a post on this blog last month, Kelly Wakefield discussed how we understand natural hazards and some of the societal implications of this.

Senkbeil et al. argue that all these factors must be understood for our response to natural hazards to be effective. That, say the authors, is something that an interdisciplinary subject such as geography, is well placed to deliver.

The Guardian (6 September 2011) Hurricane Irene relief fund estimated at $1.5bn

Senkbeil, J. C., Brommer, D. M. and Comstock, I. J. (2011) Tropical Cyclone Hazards in the USA. Geography Compass 5 (8): 544-563

Earthquake impacts

I-Hsien Porter

Shih Gang Reservoir, China after a 2005 earthquakeOn Monday night, a small (magnitude 3.3) earthquake struck near Ripon, North Yorkshire. Although the tremors were felt up to 100 km away, the earthquake did not cause very much damage.

Although the UK experiences a few hundred earthquakes every year, most are too small to be felt. Across Europe, large earthquakes are rare. However, in the Mediterranean, where the African tectonic plate pushes north into the Eurasian plate, damaging earthquakes have been known to occur.

In a recent article in The Geographical Journal, Chester and Chester explore the impacts of two major earthquakes in the eighteenth century, on the Algarve region of Portugal. One event, in 1755, cost between 32 and 48% of Portugal’s gross national product at the time.

Were this event to occur again now, in an urbanised tourist region, far more people would be affected. However, because such large events are rare, it’s difficult to forecast when they might recur.

A continuing challenge for scientific researchers is convincing decision makers to take action (emergency planning or preventative action), with such a high level of uncertainty. However, geography has a key role to play in understanding both the physical processes and their potential impacts on human lives, informing decision making about these risks.

Chester, D. and Chester, O. (2010) “The impact of eighteenth century earthquakes on the Algarve region, southern Portugal.” The Geographical Journal 176 (4): 350-370

BBC News (3rd January 2010) “Earthquake Hits North Yorkshire”

Can we ‘prove’ climate change?

I-Hsien Porter

A view of flooding in Pakistan, taken from a helicopter near Ghazi, August 2010.

Referring to the ongoing heatwave in Russia and floods in Pakistan, a broadsheet newspaper recently printed an article with the headline “Disasters ‘prove that global warming is happening’.” The article was reproduced on the internet, with the more cautious title “global warming could be the cause.”

The Intergovernmental Panel on Climate Change (IPCC) agrees that extreme events like these are consistent with climate trends. However, global warming refers to long term climatic trends over periods of decades. Heatwaves and flooding, however extreme, are short term weather events. They do no more to ‘prove’ global warming than heavy snowfall across the UK in January ‘disproves’ it.

Extreme events have always happened. What we’re concerned about are long term trends in climate, which might make these sorts of events more common. But we can’t wait around for these trends to play out over decades before concluding that we have observed ‘proof’: by then it will be far too late to mitigate any damage already caused. So what constitutes scientific proof?

In a paper in Area, Greg O’Hare reviewed the uncertainties in climate science, ranging from measurement errors in data collection to simplifications introduced into computer models. The world’s climate system is complex and our knowledge and ability to measure it is incomplete. Scientists can only draw interpretations about climate change from the available evidence, albeit using increasingly sophisticated techniques such as computer models. Linking observations with the process of climate change is, therefore, an uncertain business.

Scientific research is inherently uncertain (if we were sure, there would be no point to research). While scientists can do their best to quantify and reduce uncertainty, the level of uncertainty that we are willing to accept when making decisions is a question for policy makers and wider society.

“Pakistan floods: Climate change experts say global warming could be the cause”, The Daily Telegraph, 10th August 2010.

O’Hare, G. (2000) “Reviewing the uncertainties in climate change science.” Area 32 (4): 357-368

Drought – the world’s dominant natural hazard

Drought_Swimming_HoleBy Troy Sternberg

Texas and Australia are experiencing extreme droughts that have not been seen for a half century or longer. Amid much press coverage government efforts to mitigate drought range from no water for gardens to aid, emergency loans and town prayer services (yes, in the U.S.). Drought is the world’s dominant natural hazard, thus can be no surprise in dryland regions. The severe impact comes from human efforts that are often inappropriate to the environment – farming in the desert, large populations where there are limited resources, the desire for swimming pools and green lawns in scrub land. The last century has seen myriad attempts by man to conquer the desert. Great effort and expense have made miracles happen, but these are temporary victories dependent on ever-increasing external inputs for success. For long-term survival in the desert we should look to the indigenous dwellers – camel, cactus, or lizard – and treat water as a scarce resource, maximize efficiency, and limit extraneous effort. Until this is learned human extravagance in arid lands will persist and the physical and economic effects of drought will continue to alarm us. Nature makes drought endemic, it is we who must adapt – the sooner the better.

world Read more in The Economist

world Read more in The New Zealand Herald

world Pressurised pastoralism in South Gobi, Mongolia: what is the role of drought? By Troy Sternberg, Nicholas Middleton and David Thomas Transactions of the Institute of British Geographers