Another major landslide in the Rio de Janeiro area of Brazil

 O Globo in Brazil is reporting that another large landslide (in Portuguese "deslizamento de terra" for those looking the original website) struck the Niteroi area overnight, burying up to 50 houses, following the multiple slides yesterday.  The slide (shown below in an image from O Globo) occurred at Viçoso Jardim, in the Niteroi suburb of Cubango.  At least five people have been killed, with an unknown number of people missing.  The site is reportedly an old garbage dump that has subsequently been occupied by illegal dwellings.

Overall the toll from this multiple landslide disaster is very high.  To date the confirmed number of fatalities is 150, with 135 people injured and 40 or so still missing.  The Civil Defense agency is reporting 806 rainfall induced events, most of them landslides of various types. The reader-led O Globo map of the distribution of the events is a fantastic resource.  Hopefully it will be visible here:


Visualizar O mapa da devastação no Rio em um mapa maior


The landslides vary in size and nature considerably, but some are quite large, as this AP image shows:

Widespread landslides in Rio de Janeiro and Niteroi in Brazil

Over the last few days the city of Rio de Janeiro, and its twin city Niteroi just across the water, have been affected by extremely intense rainfall - a reported 288 mm in 24 hours.  The upshot has been a series of flash floods and landslides that have killed over 100 people so far.  More heavy rain is expected today.

O Globo has produced an interactive map of the Rio and Niteroi regions in which readers are invited to add information about their area.  This gives a first order estimate of the impacts of the rainfall:

Alagamento = flooding;
Lixo, lama e avores = garbage, mud and trees
Deslizamento = landslide
Postos de deocoes = Donation stations

It appears that many of the slides have affected the shanty towns constructed on the hillsides around the cities.  Over the next few days I will try to collate a list of the major fatality inducing landslides, but for now
O Globo has these two images of landslides that have affected residential areas:

Strangely, it is often a slightly abstract image that captures the horror of the event.  O Globo also has this exceptionally powerful photograph:

Finally, it is interesting to note that this rainfall event appears not to have been captured by the TRMM landslide warning system:

24 hours of rainfall (the yellow circles indicate those areas considered to be at risk of landslides):

72 hours of rainfall (the yellow circles indicate those areas considered to be at risk of landslides):

More later.

Beichuan - photos of the aftermath of a natural catastrophe

This is the first of my series of photographic reviews of the earthquake affected area in Sichuan Province. The other sets are as follows:
Part 1 (this part): Beichuan town
Part 2: The Tangjiashan landslide
Part 3: Hanwang town
Part 4: The Mianyuanhe area
Part 5: The Xingyiu area

Thanks to my friends in the State Key Laboratory for Geohazards at the Chengdu University of Technology I have spent the last few days in Sichuan Province visiting some of the key sites destroyed in the 12th May 2008 earthquake with the aim of developing some collaborative research projects. I have been fortunate to be able to visit places such as Beichuan and Tangjiashan. Over the next few days I will try to post a photographic summary of various locations.

An appropriate though tragic starting point is inevitably Beichuan, the town that was so devastated by both the earthquake shaking and by the effects of landslides. I am one of the few outsiders to be able to visit the town. It was a very emotional experience - I hope that below I can portray the state of the place, which has now been permanently abandoned with the intention of transforming it into a permanent memorial to the earthquake and its victims. The toppled lions below seem to symbolise the fall of the town:


The Google Earth image below shows the location of Beichuan within China. Its location in terms of lat and long is 31°50'2.0"N 104°27'30.5"E. Click on the image for a better view - this is the case with all the images in this post.

I managed to find two pictures of Beichuan before the earthquake. I guess that the place was not architecturally much to write home about, but the location is / was very beautiful, such that the town had many tourist hotels within it. Before the earthquake the town had about 20,000 residents.

Beichuan's misfortune was to be relocated right on the fault that ruptured to cause the earthquake. The fault runs through the middle of the newer part of the town - I have annotated the approximate surface trace of the fault on this image below, whilst the following photograph shows the surface expression of it:

The intensity of the earthquake shaking at Beichuan was clearly very high. A good indication of this is the rear jib of a tower crane that was standing in the town - the intensity of the shaking has caused the jib to bend as a result of the forces acting on the rear counterweight, despite the bracing.

Fortunately the crane did not collapse, unlike an adjacent one:

The impact of the shaking was first to cause many buildings to crumple. A substantial number underwent so-called "soft storey" collapse, where the bottom few floors pancake whilst the upper floors remain intact (the smaller rooms on upper floors mean that the building is often stronger at higher levels, whilst the larger open spaces on the lower floors (for reception areas, shops, restaurants, etc) mean that the building is weak at this level). Of course soft storey failures are particularly serious when the earthquake strikes during the day as the lower floors tend to be more densely occupied then. The following building underwent a soft storey failure - note how the lower floors have almost completely vanished:

Many other buildings partially or completely collapsed, many creating essentially impenetrable piles of debris that killed, injured and trapped thousands of people:

One of the great fears in the aftermath of earthquakes is what the insurance industry call "fire following", when the damaged buildings ignite and burn as a result of ruptured gas mains, burst gas cylinders, overturned candles and fires, and suchlike. Fire following does not seem to have been a big problem in Beichuan, although one or two of the buildings do show some fire damage:

Unfortunately, worse was to come for the people of Beichuan. In the new part of the town the Middle School was located at the toe of a large rock slope almost directly on the fault trace. The earthquake immediately triggered a massive landslide on the slope that crashed down directly onto the school and adjacent buildings.


The landslide was particularly damaging as the slope collapse took the form of massive boulders (each several metres across) that bulldozed everything in their path. The image below shows the location of the school - all that was left was the flag pole and a solitary basketball hoop. About 600 people died in this landslide, including almost all of the children in the school:

According to local people, about ten minutes after the main landslide a second massive slope failure occurred, this time above the old town on the other side of the river. Of course the landslide slid into and over buildings that were mostly already greatly weakened or even collapsed from the earthquake itself.


This landslide appears to have been extremely rapid, pushing an air blast ahead of it that destroyed almost all of the remaining buildings in the old part of the town. The devastation is almost total:

1,600 people died beneath this second landslide, bringing the death toll in the town as a whole to an estimated 12,000 people. The victims are remembered in a simple but very emotive memorial that is located in the centre of the town:

Unfortunately, for the people of Beichuan and for their rescuers the troubles were not over as upstream of the town the river valley was blocked by the massive Tangjiashan landslide. Those people who read the blog back in May and June will remember my multiple posts on this issue as we followed the ultimately successful attempts to drain the lake. I will post here about my visit to Tangjiashan in the next day or so, but for now this is a photograph of the channel upstream from Beichuan through which the flood wave from Tangjiashan travelled. The multiple landslides that are shown here were primarily triggered by the flood waters undercutting the slope toe:

One of the great problems in earthquake-affected mountainous areas is that the huge amounts of sediment released by landslides make the area very susceptible to debris flows. The final ignominy for Beichuan was that in September the area suffered from exceptionally heavy rainfall that triggered extensive debris flows. Many of the remaining buildings were buried up to and sometimes beyond the second storey. Parts of the old town were covered in 10 metres of sediment:


This is of course why the decision of the government to relocate the town of Beichuan is quite right. I just hope that after all that they have been through the people of Beichuan can find some stability.

A final footnote - I suspect that this may not be the first major slope failure at Beichuan - this huge boulder apparently predates the earthquake (there are mature bushes growing on it). It is located about 100 m from the toe of the slope - I wonder how it got there?

Other parts of this series are:

This is the first of my series of photographic reviews of the earthquake affected area in Sichuan Province. The other sets are as follows:
Part 1 (this part): Beichuan town
Part 2: The Tangjiashan landslide
Part 3: Hanwang town
Part 4: The Mianyuanhe area
Part 5: The Xingyiu area

Your comments and corrections are as every very welcome.

A new landslide video from Bolivia

I have come across another video of a landslide from Bolivia. I suspect that this is the recent slide in La Paz, as per the following report from The News:

"At least 300 people have been injured in the Bolivian city of La Paz following a serious mudslide, Mayor Juan del Granado said Tuesday. "The (movements) are still ongoing but we are talking about more than 60 families affected and 300 people injured," del Granado said. Until now we are talking about more or less 50 houses that are affected," he added. The landslide affected an area of four hectares and was caused by "the presence of subterranean water, which lubricated a level of earth" according to Johnny Bernal, a municipal expert. No fatalities have been reported"

The video is a news report Carried on Live Leak. It is available here, or you should be able to view it below:



Some pretty dramatic imagery of the impact of landslides in urban areas.

Brazil landslides

Over the last month Brazil has suffered terribly from heavy rainfall that has induced extensive flooding and landslides. Over130 people have been killed to date.

This week, Minas Gerais state has been heavily affected. The Latin American Herald Tribune has today released this image of some of the damage. It shows how small, shallow soil slips are causing extensive damage to houses.

Cairo landslide - the fall out continues

The Manshiet Nasser landslide continues to cause a huge political row in Cairo. Perhaps most importantly the population of the affected area remain deeply concerned about the nature of the response by the authorities, and their subsequent treatment. I suspect that this will rumble on for a long time. The rescue and recovery efforts have now ceased - to be honest this is probably the right decision as trying to excavate those boulders would be a terribly dangerous task, although one must feel deep sympathy for those whose relatives remain buried. Unfortunately, there is also a big political argument over the number of entombed victims - Almasry Alyoum reports that:

"Official papers said 92 corpses had been pulled out of the rubbles and only 12 corpses remained under the rocks. The Secretary General of the ruling National Democratic Party (NDP) Sheikhdom in Manshyat Nasser,however, said there are still 180 corpses under the rocks. This was confirmed by some Deweiqa inhabitants"

To me the higher figure would seem more likely, but who knows? I guess if the victims cannot be recovered then there is a need to try to ascertain a correct figure.

Meanwhile, The BBC is reporting that: "Prime Minister Ahmed Nazif will oversee a review of some 13 unauthorised suburbs of the city, with special focus on areas close to unstable land."

This seems reasonable, but such an approach will need to be undertaken with great care. Whilst people are undoubtedly at risk in some of these locations, making people homeless or putting them in refugee camps also carries very high risks. The key is to ascertain the actual nature of the hazard associated with the rockfalls. Whoever gets this task might like to look at some work that we undertook in Gibraltar to determine the hazards associated with rockfalls in residential areas:

Massey, C., Hodgson, I. and Petley, D.N. 2006. A rockfall simulation study for housing development in Gibraltar. Proceedings of the 10th IAEG Congress. Paper number 377. 9 pp.
Download the paper from here.

Loss of life in the Manshiet Nasser (Cairo) and Taoshi township (Shaanxi) landslides

Xinhua is now reporting that the death toll in the Shaanxi landslide has now reached 254. They also report that the recovery teams are yet to search two channels in which local people believe more bodies are buried

AFP is reporting that the number of fatalities in the Manshiet Nasser (Cairo) landslide is now 82 people, with at least another week of recovery work to follow. Interestingly. they also report that "Residents have blamed the rock slide on work that had been going on for several weeks on the Moqattam hill overlooking the shantytown". It would be interesting to find out more about this work.

The location of the Cairo landslide

Thanks to posters over at the EgyptSearch forum, and in particular poster AntonD who finally identified the place, I can finally identify what I think is the location of the Cairo landslide. The point is at: 30 degrees 2.728 minutes N, 31 degrees 17.261 minutes E. This is the Google Earth image of this point:


The cliff from which the failure occurred is clear, as are the houses below. According to various people there has been considerable development in this area since the image was collected.

Helpfully, the following image is online of the cliff before the failure. The image is on a Panoramio site belonging to Hazem Mamdouh:
It appears to me that this image was taken from on top of the railway embankment. Compare that with this image, taken from Ghafari's Picassa site, of the aftermath:

I will try to post an analysis of the two images by Sunday.

In the meantime, there is a good analysis of the background to the landslide here. The official death toll is now 62, whilst the recovery operation looks increasingly difficult due to the size of the boulders.

The death toll in the Shaanxi tailings dam disaster is now listed as 151 people, with more victims to be recovered.

Updates on the Cairo and Shaanxi landslides

It is unusual to have two major stories running simultaneously about landslides so here is a combined update:

1. The Manshiet Nasser landslide in Cairo

The death toll in the Cairo landslide disaster continues to rise - it is now officially 69 people. There seems to be considerable confusion about how many people are left trapped - but is fair to say that there is now no hope of rescuing anyone alive. The magnitude of the task in terms of recovery is shown well by the picture above.

There is some discussion on the newswires about the causes, with several suggestions that sewage in the joints may have played a role. To me this is far from clear. There are also now suggestions that quarrying may have occurred on the rock face - this would be the first thing that I would look at if I was investigating the slide.

Meanwhile, there appears to be considerable political fall-out over both the government's failure to recognise the threat posed by this slope (see here) and the slowness of the response. This has led the government to seal off the site. One wonders whether we will ever know the true toll of this event.

2. The Taoshi township flowslide in Shaaxi



The pictures emerging from the Taoshi township site continue to horrify. The official death toll is now 128, but there can be no hope of anyone else being found alive. Officials are now admitting that the number of missing people is "several hundred". The debris flow was reportedly three stories high and 600 m wide when it hit an office building, a market and several houses. At the time the market was just starting and there was a meeting, attended by over 100 people, in the offices of the mine company. Only three people survived the meeting.

Again, the difficulties of recovering victims here may make it difficult to estimate the true impact of this event.

The Cairo rockslide foreseen?

EPA/MIKE NELSON image showing the displaced blocks at El Doweiqa

The death toll in the rock slide at El Doweiqa in the Manshiet Nasser slum of east Cairo is slowly creeping upwards. At the time of writing it has exceeded 30 people, but unfortunately as the image below shows the likelihood is that it will be much higher once these huge blocks have been shifted (if ever). As an aside, the news reports tend to refer to these blocks as weighing hundreds of tonnes. In fact they are probably much heavier than this - a 10 x 10 x 10 m block typically weighs over 2300 tonnes. Some of these blocks may be substantially larger than this, suggesting that blasting will be the only option if the victims' remains are to be recovered.

EPA/MIKE NELSON image showing the displaced blocks at El Doweiqa

There are interesting sets of amateur images here and here.

Most interesting however is an article from the "Egyptian Gazette" dated 23rd July 2006. I have reproduced the article below. Compare the photograph with the image at the top of this posting - it is clearly the same location.

The text of this article says the following:

"NOTHING can be more difficult for a human being than to wait for the death that's drawing nigh. How can someone live in a house at the bottom of a hill while a huge rock is poised precariously at the top, ready to roll down and smash that house to smithereens? Gomaa Abdel-Bari, whose family live along with 2,800 others in el-Doweiqa, have experienced rocks falling on them from the hills above, damaging the walls of their homes.

"I've made numerous complaints to official bodies, including the local administration and human rights organisations, but in vain," Abdel-Bari told October weekly magazine. To prevent more rock falls, local inhabitants say they want to demolish the rocks that threaten them, with the help of machinery belonging to the local council. "We've already broken up some of the rocks, at a cost of LE4,000, money collected from poor residents," explains Ashraf Abdel-Tawwab.

But we cannot afford to demolish the rest on our own. Besides, it's dangerous work. If one rock comes loose, it can cause a domino effect, resulting in a disastrous avalanche," he says bitterly. Ahmed Hosni, a worker, explains that sewage leaks through the rocks, dislodging them and causing them to come tumbling down on their homes.

Meanwhile, a man called Farid Abdel-Tawwab complains of the snakes and dangerous insects that have killed many people in this randomly built area. He too says that the rock falls are to be blamed on sewage leaks. El-Doweiqa forms part of Manshiyet Nasser, the biggest shanty town in Cairo and a big headache for successive governments. It occupies around 850 feddans of land and is home to 1.3 million people, who live in appalling conditions, deprived of clean water, adequate sewerage and even fresh air, due to the huge piles of garbage collected and sorted there by the garbage collectors from all over the capital.

At the end of the last century the Government started to replan Manshiyet Nasser, including el-Doweiqa and other districts. The dea was to replace the old, unplanned districts with new, modern ones. Germany and Abu Dhabi supported the ambitious project. However, no-one knows exactly when the development project will reach the Khazan area of el-Doweiqa and whether it will be in time to prevent another tragedy like that in el-Moqattam in 1992, when a huge rock crushed dozens of citizens to death."

Thus, this two year old article appears to foresee the event that occurred this weekend. One wonders if the interviewees, and their families, survived. Tragic.

Early reports of a rockslide disaster in Egypt

The newswires are providing early reports of a terrible rockslide at Deweka (also reported as Bekheit and Manshiyet Nasron) on the outskirts of Cairo in Egypt. The slide appears to be a rather strange failure of a rock slope, releasing huge boulders that have buried several (and possibly many) buildings.

This Al Jazeera post contains a very useful report and also has this image of the site:


They are reporting that "Officials said at least eight rocks, some measuring 30m high, had buried more than 50 homes in the poor district of Manshiyet Nasron on Saturday. At least 18 people have been declared dead and 35 injured. Some estimates put the number of buried at 500."

Early reports like this often over-estimate the losses in an event such as this, but if these boulders have hit residential buildings then the toll could be terrible. Al Jazeera also note that "In a survey carried out by UN Habitat, a human settlement programme, Manshiyet Nasron is described as "the largest squatter/informal area in Cairo. There are 350,000 persons living in this area on about 850 acres with a gross residential density more than 400 persons/acre".

"The area is suffering from poor living qualities, inadequate services, lack of infrastructure, and deteriorated environmental conditions. The site is characterised by sharp contour variations ranging between 56 and 200m," the survey said."

The final point to note is that Al Jazeera claim that "Manshiyet Nasron residents had informed the authorities a year ago that there was a split between the rocks, a potential danger to the homes below." This would make sense as the image above seems to show dry conditions and there are no reports of an earthquake. Thus, the landslide is most likely to have been caused either by progressive failure (i.e. a slow loss of strength through time) or slope cutting.

I will post again when I have more.