LOCATION OF SIKKIM & PROJECT AREA

GLOF RISKS IN SIKKIM

Clear loss of approximately 14 km2 of Glaciers in Sikkim Himalayas in only 13 years.

This has led to formation of 300+ glacial lakes of which about 14 are considered to be vulnerable with South Lhonak being most vulnerable.

Source: Sikkim State Council for Climate Change

GLACIAL LAKES IN SIKKIM

Source: Sikkim State Council for Climate Change

In Sikkim Himalayas, the melting of glaciers is associated with the formation of proglacial lakes

Expanding glacial lakes has enhanced the risk of Glacial Lake Outbursts Floods (GLOFs)

Some of the vulnerable lakes include South Lhonak lake, Shako Tsho, Teesta Khangse lake, Gurudongmar lake etc

GROWTH IN AREA OF GLACIAL/MORRAINE DAMMED LAKES

Source: Sikkim State Council for Climate Change Area in Sq. KM

Study conducted by Central Water Commission•Average depth of lakes was taken as 30 m •An existing constant river flow discharge was 1000 m3/s •Mathematical modelling software MIKE - II was used for the study.

FLOW SIMULATION MODELLING – SOUTH LHONAK & OTHER GLACIAL LAKES

These results clearly clarify the need to have:a) An early warning System with clear system of communication b) Evacuation and Response plan for the vulnerable communities c) Capacity building trainings for first responders from the communities and the government officialsd) Awareness and sensitisation for GLOF hazards for all stakeholders and communities

POPULATION AT RISK

GOVERNMENT OF SIKKIM - INTERVENTIONS

August, 2014 – Working Group to Study the South Lhonak Glacial Lake

September, 2016 – Government of Sikkim team with Consultants from Ice Stupa Project, SECMOL Ladakh

August, 2018 – Government of Sikkim organised a Recce Expedition. This mission was supported by SDC-UNDP 3SCA Project.

September, 2018 – Government of Sikkim undertook final mission This mission was also supported by SDC-UNDP 3SCA Project.

Water level monitoring sensor being installed at South Lhonak Glacial Lake

SOUTH LHONAK EXPEDITION – PERSONAL EXPERIENCE

OBSERVATIONS FROM THE RECEE MISSION

• Siphoning of the water using pipelines though an expensive measure due to the non availability of road in the area is one of the safest mitigation measures which does not disturb the fragile moraine structure.

• The removal of this debris will help in creating space for laying the additional pipelines and will also increase the outlet area which will allow more water to pass during the increase in water pressure in the outlet.

SOUTH LHONAK EXPEDITION

Base camp at Lhonak Valley Measurement of the Outlet Installation of Water Level Sensor

South Lhonak Glacial Lake Pipes being readied for installation Water being siphoned off the lake

WAY FORWARD

• GLOF specific Evacuation & Response Plans with Mock Drills for vulnerable communities is planned.

• Data Gap needs to be bridged with better communication.

• Robust EWS with sensors with AWS is needed for long term monitoring of lake

• Deliberations and Discussions needed with Regional partners in the Eastern Himalayan countries for shared learning.

Thank Thank you!you!