Prospective Masters Theses Topics for
Lincoln University/BOKU Joint NARMEE degree
A. Ecological Engineering
1. Evaluation of the performance and effects on soil and water quality of ‘hump and
hollow’ land recontouring
On the wet west coast of the South Island of New Zealand intensive agricultural land uses have for the last 15
years been employing a land recontouring technique called ‘Hump and Hollow’. The aim of the recontouring
is to improve surface and shallow subsurface drainage from poorly drained soils on floodplains of the major
rivers. This is achieved by excavating subsoil material to form a linear channel (the hollow) and using it to
construct an adjacent ridge (the hump). The ridge crests end up being spaced at 22 m centres with falls of 2 m
to the adjacent hollows. After construction the soil material consists of raw silts that need to be regrassed and
heavily fertilised for them to be productive. Most commonly the land use under which this practice is used is
dairy farming, and under favourable conditions grazing begins within 6 months of recontouring. This project
would involve one or more of the following environmental issues surrounding hump and hollow:

Assessment of development of soil physical and chemical properties using a chronosequence
approach

Biological amendments and their effect on soil quality

Changes in hydrological behaviour of recontoured versus uncountoured land including effects
on flood hydrographs

Nutrient and pathogen transport to surface water ways
2. Quantifying and comparing long term (geological) and anthropogenically induced rates of
soil erosion from a loess-mantled hilly landscape, Banks Peninsula, South Island
Until the recent arrival of humans the New Zealand landscape was dominantly forest covered. Maori, who
arrived ca. 700 years ago, began the process of forest removal that was accelerated after arrival of Europeans
150 years ago. Much emphasis is placed on the effects of European forest clearance on increased soil erosion
risk. New Zealand is, however, a tectonically active and dynamic landscape for which natural rates of erosion
are very high. It is important to quantify these background natural rates to assess the severity of
anthropogenically accelerated soil erosion. The project will exploit the trace occurrences of a ca. 20 000 year
old volcanic ash in loess deposits that form the soils of Banks Peninsula to quantify long term soil erosion
rates. Total glass grains and the depth (mass) of loess in which they occur will be determined for uneroded
interfluve landscape positions. An inventory of numbers of glass grains will then be carried out on eroding
spur and gully terrain to quantify the amount of material lost or gained from different landscape elements.
The results will be compared with findings from similar assays of atmospheric bomb test 137Cs. These data
can be used to assess soil mobilisation since the early 1960s. A comparison of the results will show whether
or not soil erosion under the current agricultural landscape is higher than that which occurred under the
natural vegetation of the last 20 000 years.
B. Risk Management
1. Flooding and sedimentation hazard on the alluvial fans of the West Coast, South
Island
In south Westland on the West Coast of the South Island, growth in tourism is fuelling a rapid increase in
demand for residential and business property. Because of the geography of the area much of the new
development is occurring on alluvial fans forming along the steep range front to the Southern Alps. The fans
also coincide with the Alpine Fault along which the Southern Alps are being uplifted. The weak rocks, steep
slopes and high rainfall in the Southern Alps combine to give a high frequency of landslides. The potential
for large earthquakes generated on the Alpine Fault increases the likelihood of severe, widespread landsliding
events. Massive and sudden inputs of sediment to the catchments which form the alluvial fans create a very
high hazard of aggradation or even catastrophic landslide dam burst floods. In this project evidence from
soils and tree ages from undisturbed forest growing on the fans will be used to reconstruct the historic
sequence and magnitude of sedimentation events. The data produced will be used within a GIS framework to
construct risk-of-aggradation models.
2. Risk and vulnerability assessment project – debris-flows in Westland
(Project offered by Dr Tim Davies, University of Canterbury)
A number of methods have been developed (e.g. de Scally and Owens (2004); de Scally et al (2001); Lorente
et al (2002); Kostachuk et al (1986)) that distinguish catchments and fans in which debris flows can be
generated from those able to generate only floods or debris-floods. In deciding on appropriate land-uses for
alluvial fan areas, it is vital to identify those vulnerable to debris-flows, because debris-flow hazards are
effectively unmanageable by fan or catchment modification.
It is proposed to apply these methods to the available DEM of Westland using a GIS platform, to delineate
areas vulnerable to debris-flow occurrence. This can then be compared with the presence of existing or
proposed developments to identify locations at different degrees of risk.
For more Information to this Master Theses Topics
Please contact Karl.Kofler@boku.ac.at
Tel. +43-1-47654-2614
More Information to the JOINT Master of
Natural Resources Management and Ecological Engineering
(NARMEE)
You can find here: http://www.boku.ac.at/narmee
or please contact: narmee@boku.ac.at