More than 200 people have died in landslides in Kerala in the past two years. These tragedies cannot be prevented by any government policy unless the people stand by the measures and offer their full cooperation. Adoption of technology is a must to alleviate the impact of recurring natural disasters.
Any hillock in Kerala is prone to landslides after a few days of incessant rain. If the hill has an incline of more than 30 degrees, it calls for close monitoring. If the hill has been dug up precipitously, the threat is more serious. Hills with reservoirs uphill are another problem.
Signs of landslides
• Cracks on land in the valley.
• Sudden drying up of wells in an area and an equally unexpected surge of water.
• Water piping down through the earth
• The grumble of underground flow of water.
• A discharge of water, mud and stones through tunnel-like formations in the valley.
• The flow of muddied water from upstream.
• Strange sounds from uphill.
Not all these signs may lead to a landslide but these surely warrant precautions in high-risk areas.
Counteracting measures
• Do not block streams that flow from the top of the mountains. Instead form small brooks to drain out water from flooded areas to nearby streams.
• Avoid unauthorised mining in areas declared to be landslide-prone by the National Centre for Earth Science Studies in 2010.
• Replace unauthorised small quarries with super quarries in the public sector or in private-public partnership that abide by environmental laws.
• Avoid building reservoirs on top of hills with a risk of landslide.
• Ban the construction of rainwater recharge pits in hills with an incline of more than 30 degrees.
• Regulate the construction of contour bunds in farms spread over hills.
• Do not tamper with the natural forest uphill. The pits left behind by decaying stumps of trees will funnel water to the ground and lead to soil piping.
• Leave space for water to drain out while preparing the farm land in hilly areas. Do not tamper with water channels.
• Roads built on hilly areas must have enough slopes in the side. They have to be strengthened with solid support.
• Do not fill up natural streams or divert them while paving roads. Build culverts wherever there is a natural stream.
• Control the use of excavators while ploughing up land on the hills. Make sure to dig up canals to drain out excess water.
• Put in place rigorous safety checks before authorising houses built after razing hillocks.
• Implement a special guideline for construction in mountain slopes.
The government’s role
• Form special task groups of local residents and officials of the departments concerned under the leadership of local self-government bodies.
• Train the task groups to enable them to identify landslide-prone areas, to take preventive measures and to coordinate rescue missions.
• Conduct a mapping of landslide-prone areas under the leadership of the task groups in each panchayat.
• Train all residents of areas declared landslide-prone to identify the forewarning signs of landslide and escape an impending tragedy.
• Monitor those areas before the rain starts and during the rainy days.
• Make laws to grant apt compensation for people who lose their houses or farms to landslides and the cracking up of land.
People’s role
• Be vigilant when rain pours down incessantly.
• Keep an eye on the changes in nature.
• Inform the authorities as soon as any danger signal is spotted.
• Move to safer areas as soon as a warning is received.
• Abide by the officials’ directions completely.
• Release domestic animals whenever a natural disaster looms.
• Inform revenue department officials as soon as anything strange is spotted.
How to predict a disaster
Landslides are tricky. The only way to escape a landslide is to run for your life, even scientists say on a lighter note. The joke may not be completely off the mark. Yet new technology being developed around the world may be of help to the people living under the shadow of a tragedy.
Multi-instrument monitoring systems comprising sensors, tilt metres, automated rain gauges and piezometre are prevalent in many areas including the North-East of India. However, the efficiency of this tool kit is questioned by scientists.
Italian-developed acoustic emission-based warning system is held to be promising around the world. This is cheaper than the other warning systems. The National Centre for Earth Science Studies has decided to install the systems in 10 areas in Kerala deemed to be the most vulnerable to landslides.
After the tragedy
• Move to safer areas even if the landslide was a minor one.
• Remove the remnants of boulders and trees after a landslide.
• Avoid any kind of construction in the area for at least six months.
• Dig up canals to drain out water in affected areas to avoid further slides.
• Implement closure programmes to fill the gaps formed by the landslide.
• Focus on the rehabilitation of the affected people.
• Plant tree saplings in the area.
• Use bioengineering methods to strengthen the soil.