The paper includes images of the landslide, both from aerial photography and on the ground.\u00a0 The extraordinary nature of the Leuwigajah dumpsite landslide is clear:<\/p>\n
![\"Leuwigajah](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2015\/04\/15_04-Leuwigajah-1.jpg\")
<\/a>“Deposits of the 21 February 2005 waste avalanche at Leuwigajah. (a) Aerial view on 3 August 2006 (source: GoogleEarth). (b) Longitudinal profile. Dotted area: regolith and soil; (c) Picture of solid waste deposits overlapping rice fields. Notice the smoke emissions attesting permanent deep combustion (photo: F. Lavigne, 22 July 2005). From Lavigne et al.<\/em> (2014)<\/a><\/p><\/div>\n .<\/p>\n The landslide volume was 2.7 million cubic metres of waste, traveling over a distance of about 1000 m and leaving a deposit that was on average 10 m thick.\u00a0 The team investigated the movement of the landslide, and explored its internal structure.\u00a0 They found that the landslide moved as a flow, and that the rate of movement was rapid.\u00a0 Examination of the distance that the landslide moved compared with its height change suggest that the Leuwigajah dumpsite landslide showed unusually high mobility (i.e. the apparent friction was lower than would be expected), a really interesting observation.\u00a0 The authors suggest that this may have been because the waste contained very large numbers of plastic bags, which facilitated internal deformation of (i.e shear within) the landslide mass. This extraordinary image, included in the paper, shows the essentially uniform horizontal orientations of the plastic bags in the landslide mass after the slide:<\/p>\n “Pieces of plastic bags displaying horizontal orientations along the post-disaster scarp of the dump (Photo: F. Lavigne, July 2005).” From Lavigne et al.<\/em> (2014)<\/a><\/p><\/div>\n The details of the fate of the victims are pretty horrifying\u00a0 To quote the paper:<\/p>\n “In the months preceding the 2005 disaster, fires have been reported at the Leuwigajah dump site. Eyewitnesses reported that the waste mass was on fire while moving. Fires may have spread quickly because the landfill contained highly flammable combustible material. All the bodies of the victims were burnt, and the studied material was rather deeply charred.”<\/p><\/blockquote>\n So why did the\u00a0Leuwigajah dumpsite landslide occur? The authors suggest that the normal combination of processes were present – i.e. weak material forming a slope that was too steep; etc.\u00a0 But in this case, the release of methane, possibly explosively, from the waste may have rapidly reduced the shear strength of the waste, initiating movement.\u00a0 Secondly, prior to the landslide event the area suffered three days of heavy rainfall (exceeding 80 mm per day), which drive up pore water pressures.\u00a0 And finally, the authors suggest that the ongoing fires within the debris may have progressively weakened the waster materials, creating the conditions for the landslide.<\/p>\n Of course, these types of landslides are avoidable with proper management of the dumpsite.\u00a0 And, as Lavigne et al,<\/em> (2014)<\/a> make clear, the easily forgotten factor is the extreme vulnerability of the populations at risk.\u00a0 Sadly there remain many people making a living on these highly dangerous sites.\u00a0 It is now a decade since the Leuwigajah dumpsite landslide.\u00a0 It can only be a matter of time before a repeat of the\u00a0Leuwigajah dumpsite landslide occurs.<\/p>\n![\"Leuwigajah](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2015\/04\/15_04-Leuwigajah-2.gif\")
<\/a>Reference<\/h5>\n