13 July 2018
Rohingya refugee camps: your help needed
I have written before about the severe level of risk faced by the displaced Rohingya people from Myanmar, now living in refugee camps in the Cox’s Bazaar area of Bangladesh. About a million people are living in temporary camps across a hilly area that was previously mostly unpopulated. The soils are weak, consisting of sands and soils, and of course this is an area with a monsoonal climate. The monsoon is now building in intensity, and will last for the next three months or so. Some fatalities associated with landslides have already occurred.
The hazards posed by landslides are severe. In occupying this hilly land the people have had to cut the slopes to build benches to allow the construction of bamboo framed buildings. Inevitably the cooking needs of so many displaced people has meant that the protective trees have been removed to be burnt. As supplies of wood have dwindled the Rohingya people have been forced to dig up the roots to burn as well. The consequences for slope stability are dire – the combination of weak materials (especially where the slopes are predominantly sandy), cut slopes, removal of vegetation and disruption of the soil is a toxic mix that means that landslides are inevitable. There have already been some severe slope accidents.
The magnitude of the problem does not allow slope engineering as a widespread solution, although it may help in some particularly severe locations. Across the area there is a very small number of rain gauges; the coverage is too low to provide a decent understanding of real time rainfall. In a hilly area like this orographic effects mean that there will be considerable variation in rainfall patterns over a short distance. In addition, the most serious rainfall events in the monsoon are likely to be convective – the so-called cloudburst events – meaning that a dense network is needed to be effective.
Your help is needed
I have been talking to one of a very small number of landslide experts in country trying to deal with the crisis, Marina Drazba. This is a situation in which an early warning system of some sort might be helpful, but it is far from clear as to what an effective system, which can be implemented quickly, might consist of. Given that we are talking about hundreds of small slopes over a large area, technology like slope radar is not going to be applicable. So the questions that we are asking are:
1. What effective systems are in place in similar circumstances elsewhere? Are there examples of good practice in other less developed countries?
2. What could an effective system look like in this situation?
3. How is it possible to communicate the hazard in real time if the alert is triggered?
4. How can you avoid, or manage, false alarms?
The aim here is to try to implement an early warning system quickly, if that is possible. If you have answers to these questions, please could you post a comment. Please help – we are open to any ideas or thoughts or ideas, or any experiences that you might have.