RESEARCH, INNOVATION AND ENTREPRENEURSHIP AT THE UNIVERSITY OF WAIKATO
9
testing and investigation before the slide caused
further damage to public or private properties.”
In February Ehsan and his supervisors
brought in drilling contractors to collect 1.5
metre core samples from the entire 44-metre
length of the cliff. These cores are being
carefully stored in university laboratories in
Hamilton to prevent moisture loss, and Ehsan
will spend the next six months analysing them.
Tests will measure physical and mechanical
properties, such as ‘shear strength’, which
determines shear properties of the soil particles.
As well as providing cores for analysis,
the drilled holes are serving another purpose.
Ehsan has lowered a piezometer into one hole
to measure pore water pressure,
with readings recorded every five
minutes for the next five years.
The piezometer is suspended by
a cable at the 24 metre mark, and
its pressure readings at this point
will help feed into Ehsan’s research.
Two more measuring devices
– an inclinometer and down-hole
accelerometer – have been lowered
into a second hole to measure
soil movement, land tilt and
vibration, which will also help
provide clues to the cause of the land slippage.
If ongoing research suggests the instability
is being accentuated by pore water pressure
deep underground, Ehsan says an effective
solution could be to install a 50 metre
horizontal drainage pipe at a depth of 24
metres to carry moisture away from the soil.
“This slide is getting very close to private
properties. We want to try and understand
what is causing the ground to be so
unstable and hopefully further slippage can
be prevented.”
Ehsan completed his bachelors degree
in Civil Engineering in his homeland Iran
before heading to Malaysia in 2008 to work
on his masters in Geotechnical Engineering.
He worked as a researcher on projects in
Malaysia and Singapore and then took up
the doctoral opportunity offered through the
INTERCOAST programme at the University
of Bremen to expand his knowledge in this
field. He hopes to complete his PhD in
May 2014.
INTERCOAST is a multidisciplinary
programme for doctoral students studying
natural science, social science and law. Projects
include looking at the impacts of harbour
development on ecosystems, protection
and utilisation of the harbour and coastline,
sediment studies as well as the legal issues
surrounding coastal and marine resources,
and the social changes taking place in
coastal communities.
jorat@uni-bremen.de
IT’S been just 18 months since Rena oil washed
onto 18 Bay of Plenty beaches, but already the
coastal environment is showing goods signs
of recovery. Scientists involved in the Rena
environmental monitoring programme are
now analysing data from their sampling and
these are looking positive.
Results last October, a year on from the
grounding, showed the Polycyclic Aromatic
Hydrocarbons (PAHs) from Rena oil had
dissipated in most areas of the Bay of Plenty
and coastal species which had been exposed
to Rena oil showed little or no evidence of
residual PAHs.
The results were good news for University
of Waikato scientists who have been closely
involved in monitoring the environment
since Rena ran aground in October 2011. A
quick-response survey team gathered critical
information on the state of the marine
environment before oil left the ship and this
base-line data has been invaluable to compare
against numerous studies from subsequent
monitoring phases.
Since June last year, when Rena Recovery
funding became available, the university has
led a high-level, collaborative tertiary institute
team called Te Mauri Moana, to monitor the
long-term environmental impacts of Rena.
The group includes academics and students
from Bay of Plenty Polytechnic, Te Whare
Wānanga o Awanuiārangi and the University
of Canterbury.
Following the first round of results last
year, staff and students have continued to
work on a wide range of research projects
including further monitoring and testing of
thousands of marine species.
“One of the major projects over the
summer has been to sample shellfish and
marine species along coastal shorelines
throughout the Bay of Plenty,” says the
university’s Professor Chris Battershill, who
leads the Te Mauri Moana group and is the
Chair of Coastal Science. “While there is still a
great deal of analysis to be done, it has been
positive to see that the levels of Rena oil-
derived PAHs found in shellfish has dropped
off very quickly.”
Studies have been diverse, ranging from
analysing the pollutants of Rena (particularly
oil), to looking at how microbes are helping
to clean up the oil, through to how the oil
has affected the food chain. Te Mauri Moana
has also engaged very closely with Tauranga
Moana iwi during every step of the monitoring
programme which Professor Battershill says
has been integral to the success of this
comprehensive programme.
“This is the first dedicated environmental
recovery research programme associated
with a major marine incident in the world
that has integrated western science with
Matauranga Māori, by addressing the
Mauri or ‘life force’ of Moana a Toi in
response to Rena.”
The investigative programme has created
other world ‘firsts’, such as the detailed
data collected before impact, and the
multidisciplinary nature of the programme.
“From the outset the programme
was designed to be integrated and
multi-disciplinary, where the chemical
decomposition of oils at a molecular level
could be determined and put into the context
of the whole of the Bay of Plenty ecology at
large scale,” says Professor Battershill.
As well as the tertiary institutions,
a number of organisations, government
agencies, regional and local government
councils, iwi and community groups have
been and continue to be involved in the Rena
response and recovery.
Te Mauri Moana is tasked with providing
a detailed assessment of the environmental
impact of the Rena incident and study findings
will inform future policy, regulations and
operations. Technical analysis of draft reports
is currently underway.
cbatters@waikato.ac.nz
Scientists analyse findings from
Rena environmental monitoring
GEOTECHNICAL engineer Ehsan Jorat
is used to spending time in unusual places
around the world. Now in New Zealand
conducting his doctoral research, Ehsan
is analysing yet another geotechnical
conundrum; this time atop a 44-metre cliff
in Omokoroa in the Bay of Plenty.
Ehsan, from the University of Bremen
in Germany, is half-way through his PhD
investigating near-shore and on-shore
soft sediments to provide a geotechnical
evaluation. Serious landslides in the Bay of
Plenty town claimed four homes in 1979 and
subsequent slips bring the cliff face inexorably
closer to those remaining. Ehsan is seeking to
find out what is causing the land
to fall away into the sea.
The Omokoroa landslide is
one of several soft sediment sites
within the Bay he is evaluating.
In Tauranga Harbour’s Stellar
Passage Ehsan is mapping the sea
floor to determine properties of
the sediment in preparation for
potential harbour development
in the future. Similar research
towards his thesis is underway
in Germany.
Ehsan is part of the INTERCOAST
programme, which is a collaboration between
the universities of Waikato and Bremen to
bring doctoral students to New Zealand to
study the marine systems of the Bay of Plenty
and better understand the significant changes
taking place in our coastal environment.
Waikato students conduct similar research
around the North Sea in Germany.
Earlier geotechnical studies at the
Omokoroa site suggested wave action was
affecting the cliff ’s stability. However following
testing in 2012 using Geo-tech Off-shore
Seabed Tool (GOST), which was developed
and manufactured at Bremen University,
Ehsan has determined the more likely cause
to be pore water pressure at around 24 metres
below ground level. Pore water pressure refers
to the pressure of groundwater held within
soil, in gaps between particles or pores.
Incredibly, the site at which these
measurements were taken has already fallen
away into the sea, prompting Ehsan to return
to Omokoroa earlier this year to conduct
new tests.
“Near-shore landslides cannot be
neglected in New Zealand, but understanding
the mechanism of failure is the first step before
any action can take place to prevent them,”
says Ehsan.
“In this case, the speed of the landslip
and how quickly it is approaching existing
structures has been very surprising. It was
therefore critical to employ new techniques for
PROFESSOR CHRIS BATTERSHILL
International doctoral
student seeking answers
to Omokoroa landslide
EHSAN JORAT
AFTER RENA: It’s early days but the coastal environment is showing good signs of recovery.
SHIFTING LAND: Omokoroa slip soil samples (right) ready for lab analysis in Hamilton.