The Centre For Water Research

Water level measurements in the vicinity of Winam Gulf, Lake Victoria, showed strong periodicity at either 12.8 or 26.3 hours, with strong amplification along Winam Gulf. To study the origins of these pseudo-tidal surface fluctuations and their impact on flushing of Winam Gulf, three-dimensional numerical simulations of the entire lake were carried out and validated against data collected in August 2005. The wind field was found to be the major forcing factor for the physical processes occurring in the lake, in particular by generating long period surface seiches that strongly influenced the flushing from large coastal embayments such as Winam Gulf. Given the surface seiches are a lake-wide feature, it is expected that they play a similar role in flushing the other large embayments of the lake. ELCOM numerical model was used for the simulations. To validate the model surface elevations, temperature profiles and vertical velocity profiles are compared to measurements at selected points. Sensitivity analysis were carried out to model variables like wind speed, solar radiation, light extinction coefficient, bottom friction stress to guarantee that model adequately reproduced the field measurements. After the model validation was carried out, the mass exchange mechanisms between the main lake and the Winam Gulf were studied by identifying the dispersion mechanisms and the main advection mechanism. The numerical model results showed that the mass exchange follows a complicated pattern which is determined by the wind induced seiches in the main lake. From the three dispersion mechanisms studied, the one representing the residual circulation is the most important one, being even as important as the main advection mechanism.

The Southwest Irrigation Area (SIA) consists of three irrigation districts (Waroona, Harvey and Collie) located about 90 km south of Perth. These three districts supply about 40% of Perth's dairy needs. Flood irrigation is used to boost the pasture production and over irrigation is common in the area. Due to this excessive irrigation practice during summer most of the irrigated area becomes waterlogged during an average winter rainfall season. The actual weather conditions usually determine the level of waterlogging and flooding in the area. Dry weather (below average rainfall) causes less waterlogging and relatively wet weather (above average rainfall) results in excessive waterlogging problems. The waterlogging takes a relatively long time to disappear in the following spring resulting in accessibility problems, lost opportunity for cropping and low productivity. A study was carried out to assess the impacts of wet, average and dry year/climate on the waterlogging, flooding and groundwater recharge in the SIA. A fully integrated and spatially distributed hydrological model (MIKE SHE enterprise) was used in this study. A simple approach was used to define a wet, average and dry climate using past meteorological data. The model was calibrated and validated for a subcatchment of around 8000 ha in the study area by using the physical and historical hydrological data. The validated model was used to run a number of wet, average and dry climate scenarios with three levels of irrigation. The aim was to assess the impacts of various weather conditions along with different levels of irrigation on the groundwater levels. The model (MIKE SHE enterprise) produced a wide range of results for various scenarios. These results are presented in this seminar.

A recent CWR seminar presented last February stressed the importance of improving the number of biological variables measured, in-situ and in real-time, within aquatic environments. These measurements may drive the development of hybrid numerical models, based also on the temporal dynamics of bio-molecules instead of elements only (e.g., carbon -C, nitrogen �"N, and phosphorus -P). The most challenging task will be to integrate the new stream of information into the existing models, and to select the most appropriate and informative indices that can be measured rapidly and in a cost-effective manner. To do so, a streamlined approach involves the analytical quantification of the cellular macromolecules that make up the bulk of the cellular nutrients. Knowing a priori their respective C:N:P composition and the fractional allocation in specific taxa, would allow to infer the stock of nutrients in the sampled cell. Similarly, the approach could also be used to investigate the dissolved organic matter (DOM) composition and usage by planktic organisms. However, besides its straightforwardness, this strategy may also highlight the fundamental connections between C:N:P stoichiometry, bio-molecular composition and various physiological parameters, such as growth. While some cellular components show constant quantitative ratios with cellular C (and can indeed be used as proxies of it), others vary significantly in response to environmental stimuli and/or growth. This seminar will present two recently developed models linking C:N:P stoichiometry, bio-molecular composition and organism growth. Noteworthy, the modelled variables (e.g., RNA, proteins, carbohydrates etc) can be measured rapidly and cheaply, even during field surveys. This feature appears particularly important to improve our ability to initialize or validate the numerical simulations with streams of “up-to-date” data. The practicability of integrating new simple sub-modules for autotrophs' and consumers' growth dynamics, into complex numerical models like CAEDYM, will be discussed. In the so-called “self-learning” environments, these sub-modules may eventually serve as internal dynamic controls giving to the system the ability to self-check accuracy and correct its own output.

Across the globe, surface and coastal waters face increasing pressures from development such as eutrophication and pollution from contaminants that are potentially deleterious to human and ecosystem health.  The sustainable management of such impacted systems requires a quantitative assessment of ecosystem dynamics and services to guide decision support activities. Models are used to support decision makers as they serve as virtual environmental laboratories where the functioning and sensitivities of systems can be explored, either in a natural or perturbed condition.  They are also important since they support our capacity to reconcile theory with observation. Advances in cyberinfrastructure, sensors and observation networks have opened up new challenges for the development and application of aquatic ecology models. Real-time data streams can be now be utilised not only for model validation and testing, but they can also be dynamically integrated within a modelling system to enable strategic adaptation of the model parameters as the simulation evolves. Although, such model 'learning' has been demonstrated for numerous physical systems (e.g. hydraulics), highly non-linear systems (e.g. aquatic ecology)  paradoxically suffer from insufficient data which is essential for validation and reducing model uncertainty. There is therefore a mismatch between system and model complexity, and available data-streams. Here a novel approach is outlined that integrates aquatic biochemical and cytometric data with the 3D water quality model ELCOM-CAEDYM, with the aim of developing a self-learning water quality modelling system.

Acid rain was one of the 4 issues that started the environmental movement in North America. I will use 25-35 years of data from Sudbury and Dorset, Ontario, lakes to determine if recovery of the physical, chemical and biological attributes of Canadianlakes has followed the large scale reductions in North American SO2 emssions.  Much recovery has occurred, produced,in Sudbury, both by regrowth of the urban forest which has reduced local wind speeds, and SO2 emission reductions, but the acid rain story is not over. Drought-induced re-acidification episodes now routinely follow El Nino years, and much of the long-term regional decline in lakewater sulphate has been balanced, not by a rise in alkalinity and pH, but by declines in lakewater Ca levels.  Indeed, it appears that Ca levels may soon fall below thresholds that harm Ca-rich biota, such as animal plankton, in many lakes, and this new problem may be exacerbated by climate warming.  There is indeed promising news on acid rain in North America, but the story is not over, rather it is morphing into a more complex issue involving the interaction of ongoing acidity, and Ca decline in warming waters.

For over 40 years I have been concerned with major issues facing humanity such as war and violence, hunger and poverty, environmental destruction and resource depletion. Far from being resolved during this time, these issues have broadened and deepened into an interactive, global crisis that threatens the future of our civilization, our species, and our planet. At least 15 years ago, I concluded that we cannot solve planetary problems through expertise alone, no matter how interdisciplinary it may be. What is needed is a transformation of human consciousness including our beliefs, values, ways of thinking, and perceptions. That conclusion started me on a decade-long journey to document the essential features of an emerging worldview that integrates modern science with spiritual wisdom. The outcome was my book 'The Science of Oneness'. Since then, I have been exploring why progress seems to be so slow. This seminar will address some of the issues I am pondering during this visit to CWR, including: - Why are we so incredibly clever, and yet so unwise in the way we use our cleverness? - Why are we so slow to learn from inappropriate behaviour? - Why are we so violently destructive of nature and each other? - Why are we addicted to consumption of material goods (including fossil fuels) as well as mind- and mood-altering substances? - Why do we so often opt for short-term benefits at the price of potential long-term catastrophe? - Are we aggressive, violent, greedy, addictive and short-sighted by nature, or are these a product of our culture? I suspect that a common factor underlying all these questions is the effect of trauma, before, during and after birth. Also, a key turning point in human history may have been associated with the trauma of climate change.

The Laurentian Great Lakes are comparable in size to many coastal ocean systems. As such, they experience many of the same physical processes and phenomena such as coastal upwelling, horizontal gyres, and coastal currents. Here we provide an overview of how physical processes are likely to influence three different ecological phenomena of current concern to lake and fishery managers. The first is the issue of oxygen depletion in the deep waters of Lake Erie, which continues to occur despite major expenditures to control nutrient loading to the lake. The second concerns the resurgent problem of shoreline fouling by the nuisance alga Cladophora, which also seems to defy the efforts of environmental management. Third is the question of why recruitment of some valuable fish stocks, such as walleye (Stizostedion vitreum) is so poorly predictable from spawning stock size. The physical processes of greatest relevance differ among these cases but a knowledge of the three dimensional structure of water density and motion is essential to each problem. We will describe our ongoing application of the three dimensional hydrodynamic and ecological model ELCOM-CAEDYM to these problems. A strength of this modeling approach is that it provides an avenue to assess the role of climate, which is likely to be very important to each of these issues.

The hydrodynamics of Zihuatanejo Bay were simulated based on the dynamic scenarios obtained from two field measurement campaigns. The campaigns were planned based on the wet and dry local season. Measurements of water level, discharge into the bay, temperature, salinity, wind velocity, air temperature and humidity were used as the basic parameters to initiate and feed a 3d hydrodynamic model. The dynamic scenarios resulting from the measurements show a well known estuarine circulation common in the coastal zone. The presence of gyres was observed resulting from the interaction of tidal circulation with small embayment's inside the bay. The temperature and salinity patterns were also demonstrated to be typical of shallow coastal areas. The main objective of this study was to develop understanding of the physical processes occurring within the bay, with the final objective of recommendations for the planning of a sewage discharge system that is now situated inside the bay. ELCOM-CAEDYM were used to simulate the dynamic scenarios observed, using the measured data to force the models. The current velocities, temperature and bacteria concentration results from the simulation are presented. The results show good agreement with observed field measurements.

Cyanobacteria, also known as blue-green algae, are oxygenic phototrophic prokaryotes considered among the oldest life forms on earth. They may be unicellular, colonial or filamentous and are common in all kinds of habitats, including lakes, rivers, thermal springs, arid deserts and tropical acidic soils. Most commonly they are known for their existence as planktonic members of the water column in marine and freshwater environments. Cyanobacteria may have detrimental properties when judged from a human perspective. Their extensive growth (blooms) can create considerable nuisance for management of water resources, including the production of potent toxins. The physiological and ecological function of cyanobacterial toxins remain largely a mystery. Studies have focused on interactive effects between genotypes and local environmental variables. The seminar will summarise the topical research of the Centre for Cyanobacteria and Astrobiology, which include the genetics, molecular biology, biochemistry, physiology and toxicology of cyanotoxins such as saxitoxin, microcystin, cylindrospermopsin and nodularin that are found in cyanobacterial and other harmful algal blooms; the genetic diversity of several bacterial environmental niches with particular focus on the phylogenetic description of a number of cyanobacterial genera; the study of stromatolites from Shark Bay (WA) as a model of early life on earth.

This is an informal presentation on the issues of a new paper mill constructed on the Uruguay River and on the hydraulics of the river reach near the paper mill. The construction of this mill on this bi-national river has generated tensions between Uruguay and Argentina. Currently, the International Court of The Hague is considering the case. There is very little environmental data on the site, and in particular no river field studies. In 2006 as part an environmental assessment, numerical simulations of the river reach revealed short comings in the environmental impact studies done by the paper mill company and by the World Bank. Currently, in 2008, a significant effort has begun to monitor the site, part of this effort will be devoted to confirm or reject the finding of the numerical hydrodynamics simulations.

A field experiment was conducted to investigate the near-field flow characteristics of a hypersaline brine generated by a desalination plant being discharged into costal waters via an offshore diffuser. The aim was to determine the dilution of the negatively buoyant plume as it exited the diffuser under three different discharge regimes (1/3, 2/3 and full capacity), and to relate these measurements to scaling arguments derived from laboratory measurements. Equations based on the densimetric jet Froude number F, published from laboratory experiments, were found to adequately describe the thickness of the resulting saline bottom layer and the dilution of the brine for all cases for which F > 20,. For F < 20, no laboratory results exist and the dilution was found to be greater than that anticipated from an extrapolation of the laboratory results. Dilution was found, for all flow configurations, to be greater than that predicted by the accepted design formulae (45 in this case) such that at 50 metres from the diffuser: 54 times for 1/3 flow, 59.5 times for 2/3 flow and 61.4 times for full flow.

http://www.me.caltech.edu/people/faculty/brennen.html Wave propagation is a fundamental property of all physical systems and its characteristics in many conventional forms of matter are well understood and well documented. In contrast, waves in granular materials are much more complex due to the heterogeneous nature of these systems. The key element in the mechanics of a granular system is the force chain and it is along these preferentially-stressed chains of particles that waves are transmitted. However, this process is heavily dependent on the geometry of the bed and this is prone to rearrangement even by the slightest of forces. This talk will first present results from laboratory experiments and simulations intended to explore wave propagation in a granular bed. Measurements of the wave speed and attenuation in the bed reveal the unique properties of waves in granular systems which result from the nonlinearity of the bed and the heterogeneity of the force chains. Sinusoidal waves demonstrate the nondispersive nature of a granular bed and show the transient effects of force chain rearrangement. Pulsed waves display a semi-permanent shape qualitatively similar to predictions from nonlinear wave theory. In addition to examining wave propagation in a granular bed at rest, an investigation is also carried out on a granular bed undergoing low frequency vibration which increases the granular temperature of the bed and allows for the exploration the effect of granular state changes on the wave propagation characteristics. These tests and simulations display the striking differences in wave propagation from one part of the vibration cycle to the next. Finally, the talk will describe the remarkable phenomenon manifest by 'booming sand dunes', specifically the noise emanating from tall, dry dunes that has puzzled both ancient tribes and modern scientists. This talk will describe a series of investigations of booming dunes in California's Mohave Desert and utilize the knowledge gained from the laboratory studies described above to try to explain the booming phenomenon.

CWR Computational Aquatic Ecosystem Dynamics Model (CAEDYM) can currently simulate dozens of state variables, to account for a comprehensive suite of ecological and biogeochemical processes occurring within a water body. The only biological variable that is currently measured in the field and in real-time, is chlorophyll a (chla). For its positive correlation with cellular C, chla is used as a proxy of phytoplankton biomass, and provides a picture of the spatio-temporal dynamics of the photosynthetic assemblage. Other biological parameters are only measured before or after the experiment, or simply retrieved from the literature. Any models' capability and overall performance depend on the availability of suitable information used to initialize, force (in real-time), or validate the system. Clearly not only are important the quantity and quality of this information, but also the possibility of matching the modelled processes, both in space and time. Given CAEDYM's refinement, there is evidently a disproportion between the complexity of the model and the adequacy of measured biological variables. This seminar explores the potential for novel bio-molecular measurements to contribute to the validation of CAEDYM's state variables and their internal fluxes. Besides this, the possibility for these new datasets to unravel the complexity of nutrients sources, ecosystem status, pools composition, population dynamics, and biomass is also considered. The selection of new measurements is strictly prioritized towards the availability of rapid and simple assays, and transportable instruments suitable for field-applications. This appears particularly important to reduce the mismatch between time of measurement and the simulated scenario. The integration of such data-stream may open up a new paradigm for the way ecological models may adapt their operation and configuration, in response to observed phenomena.

Integrated Water Resource Management (IWRM) is emerging as an accepted alternative to the sectoral, top-down management style that has disastrously dominated in the past. It is based on the recognition that the intrinsic complexity of interconnected biophysical, social, economic and political factors can only be addressed by combining and truly integrating social constructivist ideas of participation and empowerment with a cross-disciplinary engineering approach. To couple effectively technical issues and preference aspects a procedural guidance must be provided to the decision-making process and appropriate toolboxes designed to support planning as a systematic, integrative and iterative process. According to these requirements, a general procedure for Participatory and Integrated Planning has been conceived and implemented by the Environmental Systems Group at DEI-Politecnico di Milano and will be presented in this seminar. The talk will go through the nine phases of this procedure, introducing the activities within each phase and their interconnections both in a theoretical perspective and by providing the audience with a practical example derived from a real world trans-national case study. Particular emphasis will be given to the key-role of optimization within the procedure.

Under stable climates, native vegetation establishes a predictable amount of leaf area. If the climate becomes harsher, the amount of leaf area that can be supported is reduced. During such transitions, productivity is reduced while mortality is increased. Examples will be presented to illustrate how leaf area changes with climate, and how satellite coverage allows regional and global-scale monitoring of this key ecosystem property.

Lake restoration and management strategies focus on reducing the negative impacts of enriched or polluted inflows. These strategies become of paramount importance when lakes are used for recreational and/or drinking water purposes. Long term control of eutrophication and turbidity problems associated with large inflow loads are usually oriented to catchment management. Although it has been suggested that this is the correct long term approach, public concerns usually require immediate results. In addition, due to political and economic costs related to changes in catchment management, in-lake restoration technologies have been emerging as viable pre-treatment complement to water treatment plants, both reducing the operational costs of the water treatment plant and ameliorating the water residing in the lakes. This research investigates the effects of two in-lake technologies on the dynamics of inflowing rivers, where basin shape plays a significant role. The three lakes in this study suffer from eutrophication combined with a distinctive water quality problem: from turbidity in Silvan Reservoir (Australia), to heavy metal loads in Coeur d'Alene Lake (USA) and industrial wastes in Lake Como (Italy). We first examined the influence of basin morphology, wind speed, and wind direction on the fate and transport of two rivers flowing into the L-shape Coeur d'Alene Lake, and show how transport and mixing patterns in a lake can be greatly influenced by the shape of the lake, leading to important consequences for the plankton ecology in the lake. Secondly, in Silvan Reservoir we investigated the potential to modify the basin shape using vertical barriers, increasing the retention time and hence the barrier capacity to microbial pollution. A final in-lake technology was tested for Lake Como, using a vertically downward pointing impeller to remove polluted water from the coastal margin. Lessons from these three examples indicate that there is significant potential for in-lake remediation at relatively low cost, over relatively short timescales.

Abstract: Water movements exert strong controls on biogeochemical processes and ecosystem function over a range of spatial and temporal scales. Water transports elements across space and provides conditions that enhance biogeochemical cycling rates. Areas within the inland waters may be converted to hot spots by the movement of water. Thus, an understanding of the hydrodynamics of water bodies in bringing together reactants is of utmost importance if we want to predict when and where biogeochemical hot spots and hot moments will occur and how they might change with scale. Field measurements at different spatial and time scales and numerical modelling are used to characterize the hydrodynamics of Laguna Setubal (Santa Fe, Argentina) under different hydrological and meteorological scenarios to identify the formation and persistence of hot spots and hot moments, and to determine their implications in the biogeochemical cycles and water quality. It is expected this knowledge will be used to design management strategies for assuring the quality of the resource and the biodiversity.

Some areas of the Wheatbelt of Western Australia suffer from an excess of saline, acidic, metal-containing groundwater that can lead to problems for managing drainage. This study demonstrated that sulfate-reducing fluidised-bed bioreactors are technically capable of treating Wheatbelt groundwaters so as to reduce acidity and to remove most of the undesirable metal contaminants. The minimum hydraulic retention time for a stable process with groundwater from the region of Narembeen was more than 16 hours, and approximately 2 hours for more benign groundwater from Kellerberrin. The removal of metal contaminants and pH increase produced by the bioreactor process would lessen the environmental impacts of these waters should they subsequently be disposed to lakes and wetlands. Salts that are relatively free of metal contaminants can be produced from water that has been treated by the sulfate-reducing bioreactor, whereas salts produced by evaporation of untreated saline groundwater from Narembeen contains significant metal concentrations. Unfortunately, it is unlikely that metal precipitates captured from Wheatbelt waters by the process would be of economic value because of the difficulties of extracting specific metals from the mixed-metal precipitate. It may be possible to interface this process with desalination for local production of potable water. The cost of the bioreactor treatment of Narembeen water was estimated at approximately $3.70 kL-1, although extrapolation of full-scale process costs from laboratory experimentation should be treated with great caution. Groundwater control may be required at many Wheatbelt towns in the future. Management costs to protect biodiversity and infrastructure assets from salinisation in the Wheatbelt could be as high as $2,968 million (Sparks et al., 2006). If sulfate-reducing fluidised bed reactor technology was considered appropriate at larger scale, a decision for its use would be based on the necessity to take action and the comparative effectiveness and costs of competing technologies.

Commissioned in November 2006, the Perth Seawater Desalination Plant was the first plant to supply desalinated water to an Australian city. The plant is located on the coast at Kwinana, 30km south of Perth. The plant is designed to produce 45 billion litres of water per year (125 million litres per day), approximately 17% of the Perth supply. Environmental concerns associated with the plant were two-fold, the first being the large amount of power required by the reverse osmosis process to produce desalinated seawater, and the second being the saline discharge from the plant into Cockburn Sound which could potentially increase stratification and therefore result in low oxygen conditions. This presentation outlines detailed studies into the second issue, that is the dynamics of the saline discharge and its potential impact on oxygen levels in Cockburn Sound. Cockburn Sound is a shallow, relatively closed embayment that has been heavily impacted by industry over the past 40 years, most noticeably through significant losses of seagrass meadows. The desalination process is approximately 43% efficient, such that for every 100 litres of seawater entering the plant, 43 litres of fresh water is produced along with 57 litres of water that contains all the salt of the original 100 litres of seawater, and it thus hypersaline. This effluent discharges into Cockburn Sound via a 160m long, 40-port diffuser located approxiamtely 300m from the shoreline in 10m of water. Two detailed field experiments were conducted under calm conditions, whereby fluorescent dye was injected into the diffuser and tracked for several days in Cockburn Sound. These data, along with data collected from seasonal monitoring and high-resolution sampling, were used to validate a comprehensive three-dimensional numerical model of both the hydrodynamics and ecology of Cockburn Sound. The combination of experimental and numerical modelling results demonstrate that the saline discharge is diluted to such an extent by the action of the diffuser and natural environmental mixing processes that the Perth Seawater Desalination Plant has no measurable impact on the oxygen levels in Cockburn Sound.

In this seminar two cases of numerical modelling in estuaries and lagoons in Colombia are shown. The applications, by using the ELCOM numerical model, are in the Gulf of Uraba, on the Caribbean near the border with Panama, and the Ayapel Lagoon, a tropical in land lagoon in the Caribbean savannas of Colombia. The simulations of the Gulf of Uraba have the challenge of a very big river (The Atrato river, 2500 m3 s-1) discharging in to the Gulf producing salinity stratification in the Gulf. Also the river divides the gulf into two distinctive zones: one, to the north, showing oceanic conditions and a second one, to the south showing estuary typical conditions. The major forcings for the gulf were identified as the wind field and the tides, although small in amplitude. Three field experiments, 5 days long each, where carried out to collect data for the model calibration. A biological study is carried out at the moment to link the biology to the physics. The major problems found during the simulations were the lack of data, specially those related to the river. The Ayapel Lagoon is located in the flood plains of the Cauca and Magdalena rivers, 200 km away from the coast and at end of one of the ending branches of the Andes Mountain chain. The lagoon has the input of a bi-modal hydrological system. The challenges of this case are the lack of data to specify boundary conditions during the rainy and dry seasons, with important differences between them. For this reason, the simulations were carried out at seasonal time scale aiming the study to characterize the lagoon main currents. The boundary conditions were determined from a hydraulic and a hydrological models. Some field measurements were used to check the model results.

Celebrating its 25th anniversary and moving into refurbished premises will not distract The University of Western Australia's Centre for Water Research from its commitment to creating sustainable design and management systems for our catchments, rivers, lakes, estuaries and coastal seas. The Federal Minister for Education, Science and Training Julie Bishop will open the renovated CWR at 11am tomorrow (Friday, September 28) on the UWA campus. Since its inception in 1982, the Centre has made positive changes in the lives of approximately 50 million people globally; its technology is used in the supply of half of Australia's water; 2000 users in 80 countries are helped by its software; and its hardware monitors water-quality in 30 locations. Its Director, Professor Jorg Imberger, has received international awards for projects involving iconic destinations such as Venice Lagoon, Lake Como, Lake Victoria and Lake Kinneret, and the Sea of Galilee. Located within The University of Western Australia, the Centre has a strong basis of curiosity-driven research. It is unique in natural systems research for its ability to link modelling and field-work and in its balance between research, field operations and service to industry. In keeping with this University's aspirations of both serving the community and achieving global excellence, this Centre is internationally recognised as the leading research organisation in natural system science and engineering, UWA's Vice-Chancellor, Professor Alan Robson said. Despite our relative geographic isolation we remain vitally connected to the rest of the world. This Centre exemplifies our determination to be at the epicentre of global change and to support research that will benefit all mankind.

A draft chapter from an ethnography focusing on experiential implications of the 20 year mortality difference between Indigenous and non-Indigenous Australians will be presented. A recent conceptual reworking of the developmental origins of health and disease model that places it within a life history framework, is used to interpret some of the history of people living today in the remote Arnhem Land community of Numbulwar and to suggest some of the means by which their past circumstances may have had an impact on their current health. This effort focuses our attention on physical and social components of the environment that stress mothers and later, their offspring. It invites us to consider the manner in which environmental stressors may have intergenerational consequences for health.

This talk reports the results of several direct numerical simulations of the withdrawal of a two layer fluid with a finite thickness interface through a slot in the base of a finite rectangular cavity. Particular attention is paid to the role of long (basin scale) interfacial waves on the processes leading to drawdown of the interface into the slot. It is shown that these waves play an important role and can either delay or accelerate drawdown. This means that drawdown can occur over a range Froude numbers. The results are compared with previous work for ideal flow and experimental results.

We often wonder why we have arrived at a stage in the human development where things are changing faster than we can comprehend and or respond; physical changes such as land use developments, climate change and technology, changes to the world's biodiversity and changes to our ability to cope with life. First,an analysis of the Australian Government's funding policies since the 1960's quickly showed that much can be explained by the adoption of the 'rational economic' model; there has been a marked shift from long term societal programmes to short term financial justification. Second, an analysis of what makes people creative, shows that the recent policies of most western governments where collaborative research, accountability and setting of goals and targets is stressed and viewed as responsible actions has led to a sharp decline in creativity; I will show that essentially all important ideas are established by individuals working with modest budgets, free of the constraints of the norms of society. Third, together these two policies are leading to unprecedented levels of mental illness, collapse of cultural diversity and biodiversity; all this in a climate where the creative individuals, the people who could save us from disaster, are being imprisoned by societies norms.