Geochemical changes during recharge with tertiary-treated wastewater at a coastal sandfill

Results of experiments investigating geochemical changes during artificial recharge of treated wastewater at a coastal sandfill, reclaimed with sand dredged from the seabed, are reported in this paper. Laboratory batch experiments were conducted using secondary effluent (SE) and SE treated with an additional ultrafiltration process (UF), and wastewater treated by reverse osmosis (RO) process, mixed with surface sand obtained from the sandfill. Experiments with RO showed a net increase of 0.41 meq/L, 0.12 meq/L and 0.31 meq/L for Ca(2 + ), Mg(2 + ) and HCO(3) (-), respectively. UF and SE also exhibited net increase in Ca(2 + ), Mg(2 + ) and HCO(3) (-) indicating carbonate mineral dissolution. All three waters were found to be over-saturated with respect to calcite. Carbonate dissolution reactions were observed in the field experiments. However, the presence of imported clays from the borrow source gave rise to ion exchange reactions where Na(+) attached to the clay particles were exchanged for Ca(2 + ) and Mg(2 + ) inducing mineral dissolution, driven by sub-saturation conditions. This resulted in an increase in pH with maximum values in excess of 9.0. It was also found that the sodium adsorption ratio remained high (>10) even after the groundwater had been diluted sufficiently to freshwater levels (ionic strength, I <0.015) indicating a potential for the dispersion of clay particles. This could have a deleterious consequence on porosity and hydraulic conductivity.

Quantifying changes in building footprint in the historic coastal town of Queenscliff

The sea change phenomenon has attracted new residents to Australian coastal towns and brought with it expectations of residential housing formed in metropolitan settings. Consequently, the traditional ‘identifying’ neighbourhood character of these towns is changing. Much larger houses are now being built and site coverage has increased. To date, changes in character have been measured using data based on the subjective judgement of residents through surveys and interviews. More objective information would be beneficial in understanding change. This paper describes a methodology that has been developed to quantify the change in the building footprint in the historic coastal town of Queenscliff in Victoria. Using selected aerial photographs, the building footprint of the town's residential buildings has been estimated at four intervals from 1957 until 2006. This footprint has been compared to the block size at each interval so that changes in house-to-block ratio may be compared. Over 20% of the residential homes were assessed. Building footprint has risen from 30% to over 38% in the documented 50 years. The method developed here is a low-cost method of tracking footprint change over an extended period and informing local planners and residents of when and where the changes have occurred.

Floristic and structural characteristics of a coastal heathland exhibiting symptoms of Phytophthora cinnamomi infestation in the eastern Otway Ranges, Victoria

The floristics and structure of heathland vegetation exhibiting symptoms of Phytophthora cinnamomi Rands infestation was assessed at two sites in heathlands at Anglesea, Victoria. There were significant effects in both floristics and structure. Thirteen heathland species were significantly less abundant in diseased areas and 23 species were more abundant. Diseased (infested) vegetation, when compared with non-diseased areas, had less cover of Xanthorrhoea australis and shrub species and a greater cover of sedges, grasses and open ground. Structural differences were observed between heights 0 and 0.6 m, with a decline in cover recorded in diseased vegetation. Non-metric multidimensional scaling ordination of the floristic data showed a clear separation of diseased and non-diseased vegetation and that changes in floristic composition post-infestation were similar at both sites. Although there was some evidence of regeneration of X. australis, the recovery capacity of other susceptible species at Anglesea is unknown. The long-term consequences of loss of species and structure in the eastern Otways mean that the vegetation is unlikely to return to former status, especially if the pathogen continues to reinfect.

Meteorological influences on coastal sea levels west of Port Phillip and their engineering significance

This report presents the results of an analysis of three years of tide and meteorological data aimed at delineating the influences of atmospheric pressure, waves, onshore winds and longshore winds on coastal sea levels West of Port Phillip Bay, Victoria« The data was used to develop predictive and hindcasting techniques for meteorological tides on the Otway Coast, using statistical methods, an empirical method and a mathematical model. The nature and magnitude of contributions of the various components of the meteorological tide, and the general variability of monthly and seasonal variations were also studied. It was found that meteorological tides on the Otway Coast can account for significant sea level changes, with the main factors being wind and atmospheric pressure. The wind component of the meteorological tide was found to be approximately twice the pressure component, and longshore winds were found to be more significant than onshore winds for wind setup on the Otway Coast. The meteorological tide models developed enable estimates of wind setup and atmospheric pressure setup on the Otway Coast to be readily computed using data from synoptic charts. The wave setup component could not be separated from the meteorological tide and is included in the wind setup component. The results of the investigation are relevant to the design and maintenance of coastal engineering works, and point to the need for the establishment and operation of coastal management schemes on the Otway Coast.

The suburbanisation of the coastal communities of Sorrento and Queenscliff : measuring the effects of overdevelopment.

Architecture is often read as a marker of change. The Victorian towns of Sorrento and Queenscliff are undergoing immense change as a result of rapid modernisation and building due to the ‘sea-change’ phenomenon. It has been argued that this is adversely affecting place, diminishing ‘sense of place’, destroying neighbourhood character and leading to unsustainable development. Planning strategies such as Melbourne 2030 have exacerbated this trend by advocating increasing population densities without regard to specific local environmental or historical conditions. Richard Neville comments generally that ‘Architecture is a lightning rod for passions about community, development, taste and lifestyle. Few issues engage and enrage people more than development – whether a prominent public site … or a more local issue such as housing design or density.’ Anecdotally the increase in building footprint is one measure of cultural lifestyle change that has occurred in the last half century in the coastal areas of the Mornington and Bellarine Peninsulas. While the change from the 1950s ‘fibro shack’ to the 2000s supersize ‘McMansion’ in Sorrento and Queenscliff demonstrates increasing prosperity and sophistication, these developments show little awareness of the local coastal landscape or place identity. If the impacts of this ‘sea change’ phenomenon on place are to be considered as more than anecdotal, ways of evaluating these impacts are required. Monitoring and documenting the impact of changes to place will enable the researchers to quantify overdevelopment as site specific and recommend that modern planning schemes need to value and address place differently.

From fibro shacks to McMansions: considering the impact of housing change on the sense of place in the historic Victorian coastal towns of Sorrento and Queenscliff

Eighty per cent of Australians now live within 50 kilometres of the coast.1 While most of the population remains concentrated in the large capital cities, some people have chosen small coastal towns as their permanent and or second-home destination. Greater mobility and income has increased the feasibility and attractiveness of living in these once overlooked and forgotten towns. The arrival of these new residents has changed the towns in both positive and negative ways. Declining traditional industries have been replaced by tourism and service sectors, providing a much-needed economic revival. The expectations of new residents, both permanent and non-permanent, however, have also brought challenges to the towns. Metropolitan value systems sometimes impact negatively on the unique sense of place and neighbourhood character of these towns. This paper presents both quantitative and qualitative evidence of the impact on character and sense of place in two historic coastal towns, Queenscliff and Sorrento, in southern Victoria. Census data shows how employment and the number of permanent residents have changed radically over the last 50-60 years, altering the social fabric of the towns. An analysis of the building footprint over a similar timeframe shows a growth in building size as larger houses become more common, and a growth in planning appeals for the towns is indicative of a clash of expectations between the council, long-time and new residents. While these indicators demonstrate the impact on the character of the towns as defined by their built environment, some oral accounts of local residents are used to show the emotional impact of these changes on the traditional sense of place associated with these towns. Some specific examples of changes to the built environment are provided to demonstrate that local planning schemes are not always successful in protecting neighbourhood character and that further measures are required in order to safeguard the uniqueness of coastal towns from the negative aspects of development.

Can a modelling exercise be developed to aid and foster sustainable planning processes and guide the future growth of a small coastal Australian city?

Over the past few decades coastal cities around the world have grown at an incredible rate. With this growth have come major challenges relating to land use planning, social relationships, economic development, bio diversity and the ecological footprint. Three forces are working to influence the growth rate in coastal cities. They include: -population growth (i.e. the type and quantity of human demand for land), the existing and future properties of the land (i.e. current land status or changes due to nature and human activities), and finally technical changes to a land system (i.e. rezoning or the influence of other external factors). The goal of this research was to determine whether a planning framework could model the three (population growth, the existing and future properties of land and technical changes to a land system) variables in order to assist smaller councils undertaking long term land use planning decisions. The test site for the research was the City of Portland in western Victoria, Australia.

Design with nature : a proposed model for coastal settlements in Australia adapting to climate change and extreme weather events

The Australian coast is rich in history and is scattered with coastal settlements amongst a contrasting landscape with infinite visual and ecological diversity. These attributes provide the opportunity to create sustainable and resilient settlements, linking the wholeness of a place to the foundation of living in harmony with nature. On the contrary the coastal regions of Australia are facing dynamic changes of population growth including the looming impact of a changing climate. Acknowledging these challenges, the Australian Government highlighted that one of the key requirements for a sustainable future is to establish sustainable settlements that are resilient against the impacts of climate change. Recent government studies and reports highlighted various possible impacts to the Australian coast and regional settlements due to sea level rise with associated coastal recession, extreme weather events, flooding, and prolonged heat waves. Various adaptation frameworks are proposed to deal with this issue, but very few consider the relationship between ecological systems and human built environments. The resilience planning of settlements must consider the co-evolution of human and nature under future climate effects. This paper is thus seeking answers to the question: How can the theoretical principles of Design with Nature (McHarg, 1967) and The Nature of Order (Alexander, 1980) provide for input to a adaptation model for settlements along the coast? Reflecting on a literature review of these two well established theories, the author select key principles from both as input to a ecological design based adaptation model for coastal settlements, which establishes a system of unfolding steps to create sustainable communities that connect with the landscape, and are resilient against future impacts of change.

Landscapes in transition : local perceptions of indigenous and European settlement changes along the Victorian coast

Around the world coastal areas are witnessing dramatic changes due to the consequences of the growth of human settlements. Rapid urban expansion in coastal settlements due to ‘life style migration’ impacts negatively on environmental coastal amenities that are the driving factor behind the attraction of these areas. The Victorian Coast in Australia is under stress, with the growth pattern of coastal settlements in a sprawling linear fashion resulting in devastating effects on the natural coastal environment, biodiversity and the loss of cultural heritage. The Victorian coast is rich in history, and the coastal towns are often described in literature as places with ‘sense of place’, or referred to as place character. This place character has been formed over many years with the interaction between social histories and natural environments woven together across time. This paper reviews the transition of the landscapes along the Great Ocean Road coastal region, and ask the question how can a potential Generative Plan be developed to establish a process to keep the place character of coastal towns. The proposed plan considers the interrelationships of nature and people as fundamental to forming place character, from the time of Indigenous habitation before European settlement, to the current day of rapid increased developments scattered along this coast.

A tale of two Victorian historic coastal towns : dilemmas of planning and conservation in Queenscliff and Sorrento

Change has engulfed the coastal fringe of Australia. In balancing the built and natural environment, community needs, cultural significance and economic sustainability, planners aim to improve quality of life and create vibrant communities. Yet managing place change, particularly in coastal areas, is fraught with tensions. Most planning discussions about the rapidity of change, the impact of the Sea Change process and increased development have focused upon the extensiveness of residential expansion and the housing styles that challenge the essence of the character of these coastal towns. Character and sense of place qualities are the very reasons that sea changers desire to engage with and reside within these communities. One aspect missing from this discussion and analysis is the impact that large-scale transformations of iconic buildings are having upon these places. This paper examines the consequences that major commercial development projects have upon the communities of Sorrento and Queenscliff. It considers changes (proposed or realised) to four landmark historic hotels: The Koonya and Continental in Sorrento; and the Ozone and Vue Grand in Queenscliff. This paper focuses on issues of planning, social engagement and community debate.

Paleoreconstruction of estuarine sediments reveal human-induced weakening of coastal carbon sinks

Human activities in coastal areas frequently cause loss of benthic macrophytes (e.g. seagrasses) and concomitant increases in microalgal production through eutrophication. Whether such changes translate into shifts in the composition of sediment detritus is largely unknown, yet such changes could impact the role these ecosystems play in sequestrating CO 2. We reconstructed the sedimentary records of cores taken from two sites within Botany Bay, Sydney - the site of European settlement of Australia - to look for human-induced changes in dominant sources of detritus in this estuary. Cores covered a period from the present day back to the middle Holocene (~6000 years) according to 210Pb profiles and radiocarbon ( 14C) dating. Depositional histories at both sites could not be characterized by a linear sedimentation rate; sedimentation rates in the last 30-50 years were considerably higher than during the rest of the Holocene. C : N ratios declined and began to exhibit a microalgal source signature from around the time of European settlement, which could be explained by increased nutrient flows into the Bay caused by anthropogenic activity. Analysis of stable isotopic ratios of 12C/ 13C showed that the relative contribution of seagrass and C 3 terrestrial plants (mangroves, saltmarsh) to detritus declined around the time of rapid industrial expansion (~1950s), coinciding with an increase in the contribution of microalgal sources. We conclude that the relative contribution of microalgae to detritus has increased within Botany Bay, and that this shift is the sign of increased industrialization and concomitant eutrophication. Given the lower carbon burial efficiencies of microalgae (~0.1%) relative to seagrasses and C 3 terrestrial plants (up to 10%), such changes represent a substantial weakening of the carbon sink potential of Botany Bay - this occurrence is likely to be common to human-impacted estuaries, and has consequences for the role these systems play in helping to mitigate climate change. © 2011 Blackwell Publishing Ltd.

A method for building community resilience to climate change in emerging coastal cities

Rapidly urbanising coastal locations represent prototypes of future cities. While these "sea change" locations will face a range of issues associated with rapid growth such as infrastructure provision and enhancement of social capital, anticipated environmental impacts are likely to add significant challenges. Climate change is likely to have dramatic impacts on sea change communities through diminished potable water supplies, rising sea levels, storm surges, and increased intensity of flood events - with indirect impacts on health, financial sectors, and biodiversity. Given the inherent diversity within sea change communities with regard to age, culture, and socio-economic status there are likely to be differences in ways of adapting, the ability to adapt, and the desired direction of any changes. Cognizant of the potential enormity of climate change impacts, the need for rapid responses, and the diversity within communities, this paper proposes a participatory and transformative method to work with communities in responding to climate change and variability within rapidly urbanising coastal locations. The method focuses on determining probable futures for various communities of place and interest within sea change areas and aims to build the capacity for dynamic on-going learning to achieve those futures, both within and between the communities. Through this process community members may be empowered with dynamic and future-orientated learning skills that build upon community knowledge, innovation, and resilience.