Back to news
24 Jul 2019 | Cryosphere

Reassessing Tsho Rolpa glacial lake

2 mins Read

70% Complete
Morphological view of the lake’s end moraine dam and surroundings (Photo: Sudan Maharjan/ICIMOD)

Tsho Rolpa is a large, potentially dangerous glacial lake in Nepal that has been the subject of extensive research and monitoring for decades, with the Government of Nepal even placing it on its priority list in 1997. By 2000, mitigation activities had successfully reduced the lake’s level by 3 m, but the threat of an outburst still looms. The lake has been consistently expanding over the last 60 years and now encompasses an area of 1.6 km2, which roughly translates to around 148 standard-sized football fields. Studies have documented a 3.3% increase in the lake’s area from 2010 to 2015. An outburst flood would be catastrophic for downstream communities.

Researchers are now reassessing the state of Tsho Rolpa – located around 115 km northeast from Kathmandu in Dolakha District at an altitude of 4,560 masl – using state-of-the-art tools and technology. A field expedition to the site from 7 to 21 May 2019, led by ICIMOD and its partners, investigated the present condition of the lake and its dam and surrounding morphological conditions. The lake is directly fed by Tarkading Glacier, which continued to retreat at a rate of 60 m annually from 2009 to 2019.

The ICIMOD field expedition team also investigated Naa, Beding, Gongar Khola, and Singati villages, located directly downstream of the lake Around 6,000 households are at risk from a potential glacial lake outburst flood (GLOF), and cultivated lands, forests, and infrastructure lie in the path. This is particularly worrying because Nepal experiences the most severe GLOF-induced national-level socioeconomic impacts. A 2011 ICIMOD study reported that of 21 critically dangerous glacial lakes in Nepal, only two have been subjected to proper mitigation activities. There is consequently an increasing need to develop a reliable GLOF hazard risk assessment and warning tools to improve preparedness and build resilience at the community level.

The field expedition to Tsho Rolpa is a first step towards narrowing the research gap in exploring the latest monitoring and modelling technologies to support practical GLOF risk mitigation applications. The team observed that the lake continues to expand as a result of the rapid melting of an adjoining glacier and continues calving of surrounding ice cliffs. On the basis of the observations, the team recommended conducting bathymetric surveys in at least two-year intervals, monitoring displacement of the end moraine dam, and installing a hydro-meteorological station to monitor changes in lake features and to detect changes in the hydrological processes.

The findings from this expedition will help researchers expand their activities to other critical glacial lakes in Nepal and help the government scientifically plan effective early warning and risk mitigation strategies.

The field expedition was jointly carried out by researchers from the School of Engineering, Newcastle University; Central Department of Geography, Tribhuvan University; Himalayan Cryosphere, Climate and Disaster Research Center (HiCCDRC), Kathmandu University; and ICIMOD.

1. The exponential growth of Tsho Rolpa over 38 years (1977–2015) (Background image: Google Earth)

Stay current

Stay up to date on what’s happening around the HKH with our most recent publications and find out how you can help by subscribing to our mailing list.

Sign Up

RELATED CONTENTS

Continue exploring this topic

24 Oct 2016 News
Monsoon Discharge Measurements of Langtang Khola and Lirung Outlet

To catch the highest discharge of Langtang Khola and Lirung outlet, a team of glacio-hydrologists from the International Centre for ...

24 Jan 2018 Cryosphere
Fieldwork in the Himalaya

Getting there My heart still skips a beat whenever I recall my first field visit to Rikha Samba Glacier ...

8 Jun 2016 News
ICIMOD Meets with President of Nepal

ICIMOD along with key government organisations in the water supply sector were invited by the President of Nepal, Right Honorable ...

5 Aug 2016 News
SERVIR Workshop Helps Finalise M&E Framework

  A regional workshop on ‘SERVIR Hindu Kush Himalaya (HKH) impact pathway, partnership and communication strategy’ was held 11-15 July 2016 ...

ICIMOD and Global Biodiversity Information Facility Asia Nodes

  The 7th GBIF Asia Nodes meeting was organised in Tagaytay, Philippines 28 – 30 June, 2016 to review progress, elect ...

11 Feb 2019 Water
2nd Regional Upper Indus Basin Network (UIB-N) Workshop

Glaciers in the upper reaches of the Indus River basin are an important source of freshwater. However, as climate change ...

29 Mar 2016 Gender in Koshi
Mainstreaming Gender and Livelihoods into Water Management

Linking livelihoods and gender issues in the Koshi river basin can improve water resource management, was the key message of ...

Incubation centre established for R&D of the brick sector in Nepal

The incubation centre will strengthen FNBI’s Technical Resource Development Committee (TRDC), and enable R&D for the continuous refinement of brick ...