Stemming the landslide: GSI is working on early warning systems in India, but how do they work?

Sub: Geo

Sec: Geomorphology

Activation of New Landslide Early Warning System (LEWS):

Just before the Wayanad landslide in July, the central government activated a new LEWS for three regions in India.
Developed by the Geological Survey of India (GSI), the system predicts landslides based on rainfall data.
Currently operational in Kalimpong, Darjeeling, and Nilgiris; nationwide expansion by 2030.

LANDSLIP Project:

The Geological Survey of India (GSI), Ministry of Mines in collaboration with the British Geological Survey (BGS) under the National Environmental Research Council (NERC), UK-funded, multi-consortium LANDSLIP project has developed a prototype regional Landslide Early Warning System (LEWS) for India, and the same is currently being evaluated and tested by GSI in two pilot areas in India (Darjeeling district. West Bengal, and the Nilgiris district, Tamil Nadu).
In 2014, GSI launched the National Landslide Susceptibility Mapping, which covers 0.42 million square kilometres of landslide-prone areas in the country on a scale of 1:50,000.
- A unit of distance on the map equals 50,000 units of distance on the ground. It considers slopes, vegetation, slope-forming material and geology.
- LANDSLIP will use this database as a base map and update it as it receives new information.

How the System Works:

EWS generates and shares timely information to mitigate disaster impacts, focusing on risk knowledge, monitoring, warning, dissemination, communication, and response capability.
Scientists create susceptibility maps considering terrain, soil type, and environmental conditions to estimate landslide likelihood.
Short-term (24-48 hours) and medium-range (next 10 days) rainfall forecasts are used.
Models calculate rainfall thresholds to trigger landslides, considering local geology and past events.
These maps only show where landslides are likely to occur but do not provide an estimate of the magnitude or expected duration.

Roadblocks and Challenges:

Operationalizing the system is time-consuming, taking 8 to 20 years to collect data and understand forecasting uncertainties.
Challenges include limited rainfall and weather stations, erratic rainfall patterns, and the need for extensive data on past landslides.
Effective early warning systems require significant human power, money, and expertise.

Source: DTE