31 December 2008

10 New Year Resolutions for Safer Slopes

Posted by Dave Petley

Given the time of year, I thought I would try to put together ten resolutions that could lead to a decrease in the impact of landslides. They are in no particular order and apply at a range of scales. I would welcome any comments.

  1. Before building infrastructure, we should always map the slopes to check for potential or actual landslides. This is not a complex or difficult thing to do, but it can save a huge amount in the future. The costs of a landslide on a road, in a city or on a railway can be really serious;
  2. Reverse deforestation. There is no doubt that chopping down forests is bad news for slope stability. Increasing levels of forest loss are a huge threat in many less developed countries, and will continue to be so as population increases. Reversing deforestation is not just a task for less developed countries – there is a need to grow more, and increasingly sustainable, forests in the developed nations too.
  3. Determine how to save people trapped by landslides. In the recent landslide in Kuala Lumpur, Malaysia it took more than two weeks to find the remains of one of the victims, despite the massive mobilisation of resources. This highlights how poorly we know how and where to look for victims. There is an urgent need to research this properly.
  4. Maintain slopes properly. Far too often an assumption is made that once slope protection has been emplaced then nothing more is needed. One grows tired of hearing how a slope has failed because a simple drain was blocked. Frequent, low level maintenance can make all the difference.
  5. Mine waste and fly ash can be very dangerous if they are allowed to fail. A disconcerting trend this year has been the number of large flowslides in mine wastes and in power station ash. We have known how dangerous these materials are for over 40 years. They can be safely managed – there should be no excuse for allowing these types of disaster to occur.
  6. Landslides are a major issue during earthquakes in mountain areas. Both the Wenchuan (Sichuan) and Balochistan (Pakistan) earthquakes have highlighted the impact that landslides have when earthquakes strike, and also the impediment that they represent to rescue and reconstruction. Preparation for an earthquake in a mountain range must include preparation for landslides too.
  7. We can’t ignore climate change, which will have a substantial impact on slope stability, especially in high mountain areas. I am increasingly vexed by the rantings of the small group of people who insist on denying the evidence for anthropogenic (human) climate change. In the real science community there is no essentially doubt that climate change is real, and indeed I have noted a growing sense of quiet pessimism. In permafrost areas the rate of rockfall activity is now notably increasing, and are likely to get much worse.
  8. The biggest landslide impacts occur in less developed countries. The lack of investment in safe slopes in developing countries is frankly appalling. There is an urgent need to undertake proper research in less developed countries to understand the mechanics of the slopes properly, to identify hazardous locations and to develop sustainable ways to support and or drain them.
  9. People are the key. In all environments in which the toll from landslides has been reduced this has been achieved by creating a cadre of professional people with the skills to identify and mitigate unstable slopes, and the means to so do. Information exchange is critically important. If we wish to reduce the impact of slope failures in less developed countries then we will need to do the same thing there. It is simply naive to believe that we can achieve the same thing with community-based disaster reduction strategies or without the use of appropriate engineering.
  10. Urban growth is a major threat. The rapid growth of cities, in particular in hot and humid countries, is placing an increasing pressure on slopes that will lead to an increase in accidents unless due care is taken.

I still maintain that of all the natural hazards, landslides are the most amenable to mitigation. That thousands of people are losing their lives each year in avoidable slope accidents is a tragedy. We can and should do better!

Happy New Year to you all.