POTENTIAL DISSERTATION PROJECTS
Graduated 2009
Graduated 2008
Graduated 2007
POTENTIAL
DISSERTATION PROJECTS (Please
email me if interested)
Title: Constructing and closing the water budget for a
watershed with modelling and remote sensing
Description:
The hydrologic budget of a watershed consists of Precipitation partitioned into
Groundwater Recharge and Flow, Runoff, Stored Water in Standing Water and Plants,
and Evapotranspiration. Generally, the primary interest for society is the
runoff component, or how much water will be available for consumptive use. In
this project, the hydrologic budget will be calculated for a given watershed of
choice. Remote sensing will be used to drive a model of evapotranspiration, and
may also be used for the input of precipitation. Implications to water
availability and the effect of climate change will be explored.
Skills
gained: Modelling, remote sensing, GIS, hydrology.
Potential
publication sources: Water Resources Research; Journal of Hydrology
Advisor:
Dr Joshua Fisher
Title: Global estimation of evapotranspiration with
satellite remote sensing
Description:
Evapotranspiration is the key hydrologic parameter that links the land to the
atmosphere, soil moisture to temperature, and precipitation to water
availability. Water vapour is one of the most
important greenhouse gases, and recycling of evapotranspiration back to
precipitation sustains the world’s forests, such as the Amazon. However,
evapotranspiration cannot be measured on a regional or global scale, thus
models are required to estimate this flux. Until recently, models of
evapotranspiration on these scales were poorly designed and not straightforward
to run with existing data. In 2008, we developed a new remote sensing based
evapotranspiration model that outperforms most other evapotranspiration models
in the literature, and can be run entirely with remote sensing data. In this project,
the student will run the model either regionally or globally using MODIS
satellite remote sensing data. Implications to regional or global water
availability and the effect of climate change will be explored.
Skills
gained: Modelling, remote sensing, computer
programming, hydrology.
Potential
publication sources: Remote Sensing of Environment; International Journal of
Remote Sensing; Journal of Geophysical Research; Journal of Hydrometeorology;
Journal of Hydrology
Advisors:
Dr Joshua Fisher; Dr Kevin Tu (
Title: On the relationship between meteorology and
evapotranspiration
Description:
In a recent model of evapotranspiration, the authors describe ecophysiological
and biometeorological constraints to evapotranspiration
with which to scale down potential to actual evapotranspiration. This model, as
well as a number of the components of the model, is now being used at the
global scale, but more theoretical and experimental exploration of the coupling
processes between meteorology, plant physiology and evapotranspiration are
needed. In this project, the student will explore these processes in depth with
experimental field measurements and critical analysis of the model structure
and theory.
Skills
gained: Modelling, hydrology, field ecology.
Potential
publication sources: Quarterly Journal of the Royal Meteorological Society;
Geophysical Research Letters; Journal of Geophysical Research; Journal of
Hydrometeorology; Agricultural and Forest Meteorology; Journal of Applied
Meteorology
Advisors:
Dr Joshua Fisher; Dr Kevin Tu (
Title: Scaling individual tree sap flow measurements to
ecosystem fluxes
Description:
How does one see the forest from the trees? We provide sap flow (e.g., transpiration)
measurements on trees below two eddy covariance towers that measure
evapotranspiration at the ecosystem scale. To aid the scaling process, we also
provide an assessment of the tower footprint, a demographic census of
vegetation within that footprint, and high spatial resolution remote sensing
imagery. The student will research and develop the methodology with which to
scale up these measurements. Implications include assessing measurements over
heterogeneous terrain, particularly where eddy flux towers cannot operate
accurately.
Skills gained: Modelling,
remote sensing, ecophysiology.
Potential
publication sources: Ecology; Agricultural and
Advisors:
Dr Joshua Fisher
Title:
The carbon cost of plant nitrogen acquisition
Description:
Nitrogen is the most important plant nutrient, and the lack of nitrogen in the
soil limits plant productivity and growth worldwide. Understanding
plant-nitrogen dynamics is among the top priorities in Earth system modelling presently. This project centres
on the following question: How does a plant acquire nitrogen? Recently, we
developed a plant nitrogen model for implementation into the UK Earth system modelling framework. This model has the potential to
address many of the major outstanding questions in plant-nitrogen dynamics: 1)
Why do nitrogen fixing plants stop fixing nitrogen? 2) What limits resorption
of nitrogen from senescing leaves? 3) What limits the rate of soil nitrogen
uptake for plants? 4) If nitrogen fixers have a competitive advantage to fix
their own nitrogen, and most ecosystems globally are nitrogen limited, then why
don’t nitrogen fixers take over the world? In this project, the student will
measure and answer each of these components and questions in a laboratory-based
setting.
Skills
gained: Plant physiology; modelling; laboratory work.
Potential
publications: Nature; Science; Ecology; Ecology Letters; Oecologia;
Biogeochemistry; Plant and Soil; BioScience; New Phytologist; Functional Ecology
Advisors:
Dr Joshua Fisher; Dr Nick Brown (Plant Sciences); Dr Yadvinder Malhi
Title: Constraints to nitrogen fixation along an elevation
gradient in the Peruvian
Description:
Nitrogen is the most important plant nutrient, and the lack of nitrogen in the
soil limits plant productivity and growth worldwide. Given that nitrogen fixers
have a competitive advantage to fix their own nitrogen, and most ecosystems
globally are nitrogen limited, then why don’t nitrogen fixers take over the
world? This study explores this question in depth along an elevation gradient
along the Peruvian Andes. The focus is on the Alnus
tree, which is present along the face of the
Skills
gained: Field ecology; plant ecophysiology; isotopic
analysis; GIS; tropical ecology.
Potential
publications: Oecologia; Basic and Applied Ecology;
Ecology; Ecology Letters; Plant and Soil; BioScience;
New Phytologist; Functional Ecology
Advisors:
Dr Joshua Fisher; Dr Yadvinder Malhi; Dr Yit Teh (
Title: Isotopic tracking of nitrogen through forested
ecosystems along an elevation transect in the Peruvian Andes
Description:
The Ecosystems Dynamics group at
Skills
gained: Field ecology; plant ecophysiology; isotopic
analysis; tropical ecology.
Potential
publications: Oecologia; Basic and Applied Ecology;
Ecology; Ecology Letters; Plant and Soil; BioScience;
New Phytologist; Functional Ecology
Advisors:
Dr Joshua Fisher; Dr Yadvinder Malhi; Dr Yit Teh (
Title: Remote sensing of land surface fluxes
Description:
This project is intended to feed directly into the Remote Sensing (journal)
special issue on land surface fluxes (http://www.mdpi.com/journal/remotesensing/special_issues/rs-environment).
Excerpted from Remote Sensing: Energy, water, carbon, and nitrogen (E-W-C-N)
fluxes are all critical for humans and ecosystems and have strong links to
climate. These fluxes have been perturbed by human activity throughout human
history. However, these influences have accelerated in the past five decades or
so, causing marked changes in regional and global climate. E-W-C-N fluxes show
notable relationships and feedbacks. To quantify these fluxes at a larger
spatial scale and establish the link among fluxes and their linkages to climate
and hydrological dynamics, remote sensing approaches will be essential and
practical. The Special Issue of Remote Sensing journal will publish those full
research and high rated manuscripts addressing E-W-C-N fluxes using remote
sensing data assimilation and modeling approaches. Flux and surface parameter
estimation; evapotranspiration modeling and validation; carbon, methane and
nitrogen fluxes from different ecosystems and in relation to field or watershed
management options; remote sensing data assimilation and integration to
landscape models; fluxes and climate dynamics; spatial and temporal dynamics of
fluxes using new machine learning techniques (ANN, neurofuzzy,
and others) will be accepted. Deadline: 31 July 2009 (potentially extended).
Skills
gained: Remote sensing; modelling; land surface
fluxes.
Potential
publications: Remote Sensing
Advisor:
Dr Joshua Fisher