You are currently browsing the tag archive for the ‘flood’ tag.
Similar to other geohazards, floods are unpredictable and complex. This makes preparing for them challenging especially for communities that deal with unexpected or unforeseen flood events that may occur. Flooding is an interesting case study for understanding how geohazards and society interact which can have disastrous consequences if little preparation is made in advance. As far as floods in society are concerned they are usually understood in terms of risk, such as the likelihood that someone’s home or business may be flooded.
If the flood risk is low perhaps little is done to mitigate flooding. In some situations insurance can be purchased to cover extreme events if they should happen, but little is done overall. If the risk is perceived as high or of concern to an individual, community, county or nation, then usually flood mitigation efforts, including research, should be prioritised. If flood risk is high it begs the question why is this the case? This comes down to exposure and vulnerability.
If property or people themselves are exposed to the flood hazard, with little to no flood protection, they are at risk of losing their home, business, livelihood, way of life or even their lives. But better ways of identifying flood vulnerability are needed to help make communities resilient to flood hazards.
Professor Alberto Montanari from the University of Bologna visited IHRR recently to give a seminar on the damages and fatalities caused by flooding that has been increasing in countries throughout the world. As a hydrologist, a scientist who studies the movement, distribution and quality of water, he presented some of his recent work in identifying areas of flood vulnerability in Italy. He said ‘that flood vulnerability and frequency are intimately connected’, which includes the effects of climate change and other factors that affect flooding, such as land use. Read the rest of this entry »
10th March 2014, 13:00 to 14:00, Seminar Room 010, Dept of Geography, Professor Alberto Montanari, University of Bologna, Italy
The damages and fatalities caused by floods are dramatically increasing in many countries of the world, including in Europe and developing regions. Scientists have long investigated the possible reasons for the raising severity of floods, in order to devise efficient strategies for mitigating the above damages. There is a general consensus that is widely amplified by media, that climate change is the most important triggering factor of the increased flood hazard and vulnerability. This seminar will give an overview of recent research on this subject and will provide a forward-looking perspective on the impact of floods on human activity. Read the rest of this entry »
A satellite view of the floods at Somerset Levels as heavy rains earlier this month brought severe flooding to South West England. This comes at a time when extreme weather events have become more frequent throughout the world, particularly rainfall. In order to prepare for such events finding ways to adapt built infrastructure and coordinate services across the public and private sectors is vital.
Extreme rainfall in southern England
Southern England is currently undergoing an extraordinary period of exceptional rainfall, especially in the south, which is causing floods on an unprecedented scale. This rainfall, which is likely to be a consequence of climate change, shows no signs of abating, with further heavy falls expected over the next few days. Not surprisingly there have been many landslides, especially on the coast and along railway lines, and more can be expected. The UK Met Office provides monthly precipitation data for Southern England . I have downloaded the data and plotted the monthly time series from 1910 (the start of the dataset):
The horizontal line in the long-term mean value (77.3 mm). The 2014 total, at 165.4 mm, is 2.8 standard deviations from the mean – a truly exceptional value. And of course it is still raining, such that since the end of January the floods have got much, much worse. Read the rest of this entry »
Over the last few days Central China has been experiencing exceptionally heavy monsoon rainfall, causing very high levels of damage. The TRMM data for landslide potential for the last seven days of rainfall highlights the areas considered likely to be affected by landslides (and note that there are also substantial parts of N. India and Nepal that are experiencing problems:
Unfortunately, the worst of the rainfall appears to have affected the areas struck by the 2008 Wenchuan earthquake in Sichuan Province. This is a zone that remains very vulnerable to landslides because of the legacy of the seismic even, compounded by inappropriate development in the rush to rebuild after the earthquake. The effects have been disastrous. The largest impact to date is the landslide at Sanxi in the area administered by Dujiangyan City, which is reported to have killed 12 people whilst a further 11 are missing, with very limited chances of survival. The landslide is reportedly very large, with a travel distance of 2 km and a volume of 1.5 million cubic metres. Read the rest of this entry »
The UK’s chief government scientist Sir John Beddington announced that world leaders need to urgently tackle climate change, especially because of increasing trends towards more extreme weather events such as floods, droughts and storms over the next 25 years. The more extreme and erratic forms of weather that the UK has experienced in recent years may become more common due to a changing climate.
Prof Sarah Curtis who is the Executive Director of the Institute of Hazard, Risk and Resilience was interviewed by both television and radio media recently about what can be expected for the future. Prof Curtis mentioned the importance of planning with local authorities and national planning being taken by government to adapt to a changing climate, and that focused preparation and planning are needed to cope with variable climate and extreme weather events. Read more
On Thursday morning, there was a knock on my office door – “The BBC wants to talk to someone about snowmen” – “okay…” I reply, not quite sure where this is going. Five minutes later I am on the phone to a reporter.
It had been in the newspaper that morning about reducing flood risk by building snowmen. The Environment Agency was concerned about a rapid warming in the weather melting the snow and this released water creating a flood risk. The proposed solution from the Environment Agency was based on the fact that snow in large piles, either stacked up or as a snowman, takes longer to melt and hence would slow the delivery of the water to the rivers (see BBC News article). My first thought on this was that we would need to build a huge number of snowmen to capture enough water to have an effect. Having travelled from Durham to London and back this week, it was clear how much of the country was covered in snow. I was about to calculate the number of snowmen required to capture a significant fraction of the water (Prof. Kevin Hiscock at UEA has done this for the River Wensum catchment and estimated 6 million snowmen in that area alone) before I started to think about the problem from another perspective.
The heavy rains that hit the North East of England recently caused some major floods in the last few days. Regions of the A1 motorway were shutdown for two days between Disforth (North Yorkshire) and Bradbury (near Durham). People’s homes and businesses were also flooded in Morpeth and other cities, towns and villages in the North East due to heavy rain fall. According to BBC News, among the areas worst hit by flooding were Morpeth, Durham, Rothbury, Chester-le-Street and Stockton-on-Tees.
Some of the water levels (hydrographs) recorded by the Environment Agency show the level above previous records, while in other parts it seems to have returned to previous levels. This morning the River Swale in Yorkshire a major tributary of the River Ure which becomes the River Ouse (which caused major flooding in Yorkshire) was measured at 5.28 metres at Crakehill close to the record of 5.45. Read more
Dr David Milledge and Prof Stuart Lane present the results of a recent study they authored on flood prevention in the Yorkshire Dales located in Northern England that investigates the role of controlling surface drains (grips) to manage flood risk.
The moorlands of large swathes of Upland Britain are covered by hundreds of kilometres of surface drains or ‘grips’. These grips were originally dug between the 1950s and the 1970s to dry out the peat soil with the expectation that this would improve the vegetation for grazing and game. Grips have dried out the peat, but ‘gripping’ has since been associated with a range of negative impacts both in the moors and in the rivers that flow from them. Drying the peat both changes the ecosystem that it sustains and makes it more susceptible to erosion. This eroded peat is then transported downstream and needs to be removed from the water before we can drink it. Read more
Despite aid efforts in the past, many victims of the 2010 floods are still homeless over a year after the catastrophe occurred. According to a report released by the People’s Accountability Commission on Floods, 1.5 million people are still without shelter in districts of the Sindh province that were extremely damaged by the floods. There are also problems with providing enough resources, such as milk, exposing infants to malnutrition and starvation. The government of Pakistan ended relief activities on 31 December and are no longer providing food, tents or temporary shelter.
Here are two images of southern Pakistan taken by NASA’s MODIS. The first image was taken 24 January 2010 and the second on 23 January of this year.