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In January 1998, MeteorComm and its partner British Columbia Hydro International
Ltd. (BCHIL) of
Vancouver, British Columbia, signed a contract with His Majesty’s Government
of Nepal (HMGN), Department of Hydrology and Meteorology (DHM) to design, supply,
install and commission an audible warning system downstream of the Tsho Rolpa glacial
lake. Tsho Rolpa is the largest glacial lake in Nepal and formed at the toe of the
Trakarding glacier over the last forty years as the glacier stagnated, melted and
retreated. Tsho Rolpa is located in the Rolwaling Valley at an elevation of over
15,000 feet, approximately 20 miles southwest of Mount Everest. The lake is over
2 miles long, 0.3 mile wide and up to 500 feet deep and continues to expand. An
unstable natural moraine dam retains the lake. The current risk is high that the
dam will burst and a catastrophic out flow will occur. If the dam is breached, the
resulting flood of approximately 2 billion cubic feet of water, will threaten as
many as 6000 lives, numerous villages, farmlands, bridges, trails, roads, as well
as the construction site for a 60 MW hydroelectric project for 60 miles or more
downstream.
The warning system relies on MCC’s extended line of site VHF radio technology,
communications protocols and equipment. Nineteen warning stations were installed
at villages along the Rolwaling and Tama Koshi valleys, downstream of Tsho Rolpa.
Each of the warning stations will relay warnings to all the stations along the valley.
The unstable physical features of the moraine dam prevented the installation of
sensors directly on the dam to detect an impending breach. The system therefore
monitors the outburst flood itself and provides warning downstream that the out
flow has occurred. Once the sensors detect flooding, they trigger alarms, consisting
of air horns and auxiliary electronic sirens. The system is fully redundant to mitigate
the issuance of false alarms.
A second component of the system is the installation of an MCC Meteor Burst Master
station to be located in western Nepal. A meteor burst station uses the ionized
trails of meteors to extend the range of the transmitted radio signals to over 1,000
miles. Several of the warning stations, as well as a sensing station, transmit and
receive signals from the Master station, to provide further redundancy to the system.
The Master station also monitors the status of the entire warning system.
The system was designed, supplied and installed in an accelerated program to have
it operational for the 1998 summer monsoon season. HMGN commissioned the warning
system in late May. It has successfully operated through the most severe monsoon
season of the past twenty years. The master station will give HMGN the capability
for remote weather monitoring and two-way data communications covering over 80%
of Nepal.
Meteor Communications Corporation based in Kent Washington, USA is the pioneer and
world leader in the design, manufacture and deployment of turnkey meteor burst communications
systems. Since 1975, the company has successfully provided these wireless, packet
switched networks to its customers throughout the world.
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