Page 319 - Volcano and Geothermal Tourism

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Hall et al, 2004; Prideaux, 2004) the situation in vulnerability. In other words communities must
regard to the Tongariro volcanoes is unusual for take responsibility for their own protection. While
two main reasons (Keys and Green, 2004): there are differential implications of physical and
economic hazard consequences for community
• It is predictable well in advance of the vulnerability, resilient communities (and resilient
significant risks it raises. visitors) result from education and training in the
• The 1953 disaster and its aftermath created nature and likelihood of disaster and adequate
action precedents, some of which conflict with information about how to cope in the event of
strongly held environmental and cultural one (Munro and Parkin, 1999).
values.
Mitigation: EDS, ERLAWS
The Minister of Conservation is responsible for
the management of national parks in New Zealand and planned responses
and the Department of Conservation has produced The Department of Conservation manages two
a number of plans including an ‘Environmental early warning systems for the Tongariro National
and Risk Assessment for mitigation of the hazard Park – an eruption detection system (EDS) and the
from Ruapehu Crater Lake’ in April 1999. This Eastern Ruapehu Lahar and Warning System
followed the development of a draft Assessment of (ERLAWS) (Department of Conservation, 2008).
Environmental Effects (AEE) in October 1998 For the intending visitor, updates on volcanic activity
that presented 24 options for risk management are available from these systems at www.geonet.org.
within the following 6 categories: nz. In May 2000 the Government formalized
emergency management response and contingency
• allow a lahar to occur, but develop alarm and plans, and following discussions with stakeholders
response systems, improve land use planning and a technical design review, ERLAWS was installed
but implement no specific engineering during 2001/2002. ERLAWS consists of three types
intervention at the crater or in lahar flood of sensors at three sites in the upper Whangaehu
zones; River Valley (the crater-lake outlet stream):
• allow a lahar to occur but intervene in lahar
flood zones to reduce its size and/or confine it; • Site 1 (Crater Lake outlet) – three geophones
• prevent or reduce lahars by hardening or to detect the vibration from the collapse of the
perforating the tephra barrier at the crater; tephra dam and from lahars, a buried tripwire
• prevent or reduce lahars by excavating a trench to detect collapse of the dam and water level
through the 1995-1996 tephra barrier at the sensors to detect a sudden drop in Lake level.
crater; • Site 2 (NZ Alpine Club hut in the upper
• prevent lahar and reduce lake volume by valley) – two geophones to detect the vibration
excavating trenches into underlying lava at the from passing lahars.
outlet; and • Site 3 (near Tukino skifield) – two geophones
• defer, prevent or reduce lahars by other to detect the vibration from passing lahars.
options, e.g. siphoning or barrier trusses.
When incoming data exceed pre-set thresholds an
These options were subsequently incorporated alarm will automatically be sent to police, local
into the early warning systems now set up on Mt government offices, transport operators and duty
Ruapehu as outlined in the next section. The scientists who will then respond following
more massive impact from eruptions has also been predetermined plans. This should be up to two
discussed and programmes implemented. Following hours before the lahar reaches Tangiwai. In
the 1995 and 1996 eruptions of Mt Ruapehu the December 2000 the Ministry of Conservation also
psychological aspects of community vulnerability requested that the Tongariro National Park
were also studied and the results suggest that self- Management Plan be amended to permit the
efficacy and problem-focused coping reduce construction of a ‘bund’ or embankment to prevent

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