Getting A Grip On Landslides
On their way to the Char Dham yatra to Badrinath for the first time, Mr. Verma and his family were enjoying the cloudy weather on their route. Unfortunately, it began to rain heavily when they were halfway to their destination. They continued their journey with caution, but just a few minutes later got stuck in a 2-km-long jam. They could see from their car, with the little visibility the heavy rain permitted, that a massive piece of slope had slipped down and blocked the roadway.
A landslide is an uncontrollable downhill flow of rock, earth, debris; and is caused by heavy rainfall, earthquake etc. Landslides are among the major geological hazards that affect large parts of India about 12.6% of the landmass, excluding snow-covered areas. The Himalayas, the Northeastern hill ranges, the Western Ghats, the Nilgiris, the Eastern Ghats and the Vindhyans are heavily affected by landslides of a bewildering variety and pose chronic problems for the local communities.
There have been several tragedies attributed to landslides. In 1998, India witnessed the worst landslide which took more than 200 lives, and wiped out the village of Malpa in the Pithoragarh district of Uttarakhand. Almost 20 years later, as a result of massive rainfall, Kerala witnessed widespread landslides which resulted in heavy loss of life, property and environment. Recurring landslides demand that the problem therefore needs to be tackled for mitigation and management, wherein hazard zones have to be identified and monitoring and early warning systems to be placed at selected sites.
Keeping in mind of the above, NDMA funded a pilot project on ‘Development of Low-Cost
Landslide Monitoring Solutions.’ This early-warning system, in collaboration with National Disaster Management Authority (NDMA), Defense Terrain Research Laboratory (DTRL) - Defense Research and Development Organisation (DRDO) is developed by Indian Institute of Technology (IIT) Mandi.
It is a low-cost landslide monitoring, warning, and prediction system, which has been field tested at a Gharpa hill and a number of other landslide sites across Himachal Pradesh and Uttarakhand. This system uses motion sensors to measure soil movements. Based upon the detected movement, the system is able to activate blinkers and hooters on the roadside wirelessly so that vehicular road traffic can be alerted. The blinkers and hooters come online for 10-15 seconds with lights and sound each time soil movement is recorded at the deployment site. In addition, the system also sends SMS messages about soil movements on mobile phones, where these messages can be used to alert disaster managers, local residents as well as policy
While still being tested on a larger scale, the system has been able to generate messages about soil movements as well as severe weather advisories in advance. These predictions about soil movements and severe weather are developed via AI algorithms and machine learning models running in the cloud. Due to its low-cost and predictive abilities, this system provides immense possibilities for being used at other landslide-prone areas in India and promises reduction in losses caused by landslides in future.
While landslides are considered naturally occurring disasters which may get triggered with the onset of earthquake, or continuous weathering and erosion of the slope; human-induced changes such as construction, mining and erosion have recently caused their upsurge.
At the individual level, there are ways to reduce the frequency of landslides, such as indulging in the habit of growing indigenous plants, whose roots help in keeping the soil together on slopes. It is best to avoid building houses at the base of slopes that are prone to landslides. The community should ensure that they don’t indulge in the practice of informal settlements along the roadside.
While constructing on a slope, planned slope cutting along with implementing a design that suits the natural slope can go a long way in being safe from landslides. It is important to not obstruct natural streams or drainage paths during construction or in general as this can create blockage. One should also direct the surface water from land towards the natural gulleys enabling water to quickly drain away from the slope.
With the help of early warning systems and responsible citizen actions, it is possible to get a grip on landslides in India!