Gyoko's Climate Change

by Brad Crouch

In 1998 the tiny village of Gyoko in Nepal faced an unusual problem.  It wasn’t the blizzards, famine, poor soil, mountain predators or Maoist guerillas that the villages are used to.  The threat was flooding, at a village over four thousand meters above sea level.  Gyoko’s danger wasn’t caused by monsoon rains or mass springs melt.  At least not rains and melt from anytime recently.  Gyoko threat came from what had been a source prosperity, Tsho Rolpa, their local glacier lake (Shrestha).

The Gyoko glacier, located in the narrow mountain valley, has been in retreat for the last fifty years.    At the mouth of the valley a glacial moraine, the mass of ground up rock and soil pushed ahead of the glacier and deposited when it began its retreat, formed a natural dam.  As the glacier continued to melt and retreat up the valley, the melt water became trapped by the moraine and continued to accumulate.  At first this was a boon for the villages downstream because the small regular outflow allowed them a year round supply instead of the inconsistent summer melt water. 

However satellite photos over the last twenty years the size of Gyoko’s glacial lake more than tripled, raising fears that the natural moraine dam was no longer strong enough to hold back the lake waters (Shrestha).  This alarm was made even more urgent when in 1997 there were several small scale collapses of the moraine face, further weakening the damn. Specifically there was fear that an unusually warm summer or even a landslide from the surrounding mountains would overflow the dam, causing a catastrophic collapse and destroying the villages downstream. 

In the search for solution local officials found international help.  A grant for the World Bank and funds from the Nepalese government launched an ambitious project to drain the lake by more than a third.  From 1998 to 2002 was a constant drilling of spillways, construction of flood gates and the construction of warning systems for the 19 villages downstream.  However the project was completed on time at a cost of $3.2 million (Shrestha).

Unfortunately Gyoko is an exception.  As climatologist Indur Goklany pointed out in the June issue of “Mitigation and Adaptation Strategies for Global Change”, Nepal has experience 15 glacial lake outburst floods in the last century.  Exact figures were not kept but each time the towns and villages in the path were destroyed with almost no warning.  Despite this history the Nepalese government is incapable of controlling every lake and protecting every village.  With over 2300 glacial lakes and more than 6000 rivers and streams the locals are almost completely on their own.  Even more then the massive number of potential disasters the fact that Nepal is one of the poorest countries in the world leaves little of the meager budget to spend draining and monitoring thousands of lakes (Shrestha).  Indeed Gyoko received its aid mostly because of the hydroelectric plant under construction twenty five miles downstream.  If it hadn’t been for this important infrastructure asset it is most likely Gyoko would have been left on its own, like so many other villagers in Nepal.

However this problem of GLOF is not unique to Nepal.  While the large number of glacial lakes and poor government oversight makes deadly events more common there, GLOF’s have occurred in Canada, Peru, Iceland, Norway, Alaska and the Tibetan regions occupied by China (Casassa et al).  Low population densities in these areas have prevented any serious loss of life and as such, any serious media attention.  In addition, these countries are more technologically advance and better able to monitor, predict and warn imminent GLOFs.  While GLOFs have occurred throughout history, they are only becoming more likely as rising global temperatures cause more, rapid melting of glaciers.  Due to the power and severity of GLOFs there is very little that can be done to prevent the event.  While preventive measures such as draining the lake are an option, the remoteness of glacial lakes, extreme conditions and cost is prohibitive in most cases.  Instead; observation, warning systems, awareness and planning are the only real options to preventing more deadly events.

Works Cited

Gino Casassa, Wilfried Haeberli, Gerry Jones, Georg Kaser, Pierre Ribstein, Andrés Rivera and Christoph Schneider. "Current status of Andean glaciers." Global and Planetary Change 59.1-4October 2007 1-9. 11 Nov 2007 <http://www.sciencedirect.com/>.

Goklany, Indur M.. "Integrated strategies to reduce vulnerability and advance adaptation, mitigation, and sustainable development." Mitigation and Adaptation Strategies for Global Change 12.5June 2007 755-786. 11 Nov 2007 http://www.springerlink.com/content/4223136v69221w74/fulltext.pdf

Shrestha, M.L. and A.B. Shrestha, 2004: Recent Trends and Potential Climate

Change Impacts on Glacier Retreat/Glacier Lakes in Nepal and Potential

Adaptation Measures. ENV/EPOC/GF/SD/RD(2004)6/FINAL, OECD, Paris,

23 pp