Showing posts with label blog. Show all posts
Showing posts with label blog. Show all posts

Friday, January 30, 2009

Some interesting landslide sites

I thought that it was high time to post a summary of some interesting landslide sites:

Aowanda landslide
There is an interesting youtube video of a smallish progressive rockslide occurring at Aowanda in Taiwan here. It should also be visible below:



Not quite as dramatic as some others, but useful nonetheless.

Five disastrous landslides that changed the Canadian Landscape
There is quite a nice non-scientific piece here that describes in non-technical language five large and significant historic landslides in Canada over the last century or so. Good images!

Rockfall blog
There is an interesting new blog here that looks at measures that can be used to prevent rockfalls. Although it is in Italian, Google Language Tools do a pretty good job of translating the text. I guess one should be a little careful of the fact that it is promoting a company, but there is some nice stuff there.

The largest known landslide?
National Geographic has a nice story here that speculates that a large deposit on Mars might be the debris from a landslide that would have been the size of the United States. Working on Mars must be great because no-one can check your interpretation with field data.

Flashflood footage
It is a fine line between a debris-rich flash flood and a debris flow, so I thought that I would highlight this youtube video of a flash flood in Australia. The first minute isn't terribly exciting, but stick with it! It should be visible below:



Extraordinary video of the Baldwin Hills dam disaster
There is an excellent video of the collapse of the Baldwin Hills dam in 1963 on youtube here. This is a great illustration of the dangers associated with the formation and collapse of landslide dams. Again, it should be visible below:

Sunday, June 15, 2008

Landslides in Darjeeling, India

In September 2007 intense monsoon rainfall in the Kalimpong region of Darjeeliing in Northern India triggered large numbers of landslides, killing at least seven people. This has brought to the fore the issue of environmental degradation and the consequent landslides in Himalayan environments. Darjeeling is a microcosm of problems arising throughout the Himalaya, with rapidly increasing numbers of landslides causing major problems.

Darjeeling is probably most famous for its tea plantations, which thrive there because of the rolling topography, moderate temperatures and high rainfall. These conditions are great for tea but bad for slope stability. Preservation of the landscape can minimise the occurrence of landslides, and indeed the tea plantations generally do this reasonably well if managed carefully. However, many Himalayan regions are currently facing a near perfect storm of conditions that promote landslides - rapid population growth (which means that there are more people needing more houses and more food), deforestation, uncontrolled building to low standards, intense monsoon rainfall, and the construction of low cost roads with poor engineering standards. The upshot is all too predictable - increasing numbers of landslides with a growing level of impacts. The image below from Google Earth shows the town of Kalimpong, located on a high ridge. The slopes below are scarred with active landslides, but more importantly much of the landscape is made up of old landslides and landslide scars. Kalimpong has been seriously affected by active landsliding in recent years.


Now, as the SW monsoon rains start to build, the issue of landslides in Darjeeling is becoming pressing once again. In Darjeeling though there is one glimmer of hope, which is a remarkable campaigning group called Save the Hills, led Wing Commander Praful Rao (Retired), who campaign to raise awareness of issues associated with slope instability in Darjeeling. They have a very detailed blog in which they document both the magnitude of the challenges and the range of their activities to reduce landslide occurrence and to increase preparedness and resilience. I thoroughly recommend taking a look as it represents a model of community-level action in response to landslide threats. The main blog is here:

http://savethehills.blogspot.com/

I particularly enjoyed their images of historic landslide events, which can be found here. Darjeeling is fortunate to have such an active group, and I hope that it is able to make a difference. Many other places would benefit hugely from the activities of such organisations.