D.3 Hazard Risk and Vunrebility (landslide) 1 Flashcards
what is your case study for managing urban landslide?
Kalimpong, a hill of 1,250 m located in West Bengal, India.
what are the two key elements that cause landslide problems in Kalimpong?
Poor water management and slope disruption.
can you expand on poor water management as a cause of landslides in Kalimpong?
In Kalimpong town, water is discharged without any control into gullies that run through Dumsi Pakeha (the poorest area).
There is a lack of sewers and storm drains, large volumes of water flow unregulated into natural channels during heavy rainfall, casuing problems downstream.
can you expand on slope disruption as a cause of landslides in Kalimpong?
Some houses are built by first creating a terrace by excavating into the slope. By creating a mini-terrace to build on, a steeper slope is made behind the terrace, and that further increases instability.
what threats do landslipes pose in Kalimpong?
Small landslides threaten many houses, while larger slips have poential to go into the channel, which would brifly block it and then allow a catastrophic debirs flow to develope.
how is human acivity in Kalipung affecting landslides?
There are cases of old landslides that have been reactiviated as a resulkt of human acitivity.
For example, the community centre, which was completed in 2002, shows signs of movement.
Close to the town, the dumping of construction waste in an uncontrolled manner is adding to the problem. Adding extra weight on top of an active landslide will inevitably make the instability problem worse. Such practises should be prevented.
how are the people of Kalipung reacting?
the people living in Dumsi Pakha are not passive victims of their problems. In many cases, they are trying to manage the risk.
For example, they have built a retaining wall to try and stabilize a section of the eslope that is particually hazardus.
why is it so hard in Kalipung to stop the landslides? What is the only way to get around this problem?
The scale of the problem is so huge. Landslide accidents are inevitable in such settings unless there is better management of the slopes.
As the south-west monsoon approaches, the slopes become extremely hazardous. It is not possible to blast the steep slopes, so the only option is to monitor them and close the road then instability is noted.
what are some more consequence of the poor water management in Kalipung?
Paddy fields have been eroded and enlarged as gullies have been unable to carry greatly increased storm flows.
Erosions in gullies have now triggered extensive landslips.
Adjacent to the gullies there are slopes that are actively deforming- sliding into the channel- which will cause further erosion.
