Jan Warnken

Comparison of Fuzzy-AHP and AHP in a spatial multi-criteria decision making model for urban land-use planning

Modern planning theories encourage approaches that consider all stakeholders with a variety of discourse values to avoid political and manipulative decisions. In the last decade, application of quantitative approaches such as multi-criteria decision making techniques in land suitability procedures has increased, which allows handling heterogeneous data. The majority of these applications mainly used decision-making techniques to rank the priority of predefined management options or planning scenarios. The presented study, however, shows how spatial decision-making can be used not only to rank the priority of options and performing scenario analysis, but also to provide insight into the spatial extent of the alternatives. This is particularly helpful in situation where political transitions in regard to urban planning policies leave local decision-makers with considerable room for discretion. To achieve this, the study compares the results of two quantitative techniques (analytical hierarchy procedure (AHP) and Fuzzy AHP) in defining the extent of land-use zones at a large scale urban planning scenario. The presented approach also adds a new dimension to the comparative analysis of applying these techniques in urban planning by considering the scale and purpose of the decision-making. The result demonstrates that in the early stage of the planning process, when identifying development options as a focal point is required, simplified methods can be sufficient. In this situation, selecting more sophisticated techniques will not necessarily generate different outcomes. However, when planning requires identifying the spatial extent of the preferred development area, considering the intersection area suggested by both methods will be ideal.

Survey of users and providers of recycled water: quality concerns and directions for applied research

Users and providers of recycled water in Queensland, Australia, were canvassed to ascertain concerns about recycled water quality and directions for applied research. Some 79% of respondents had concerns about recycled water quality including microbiological components, such as viruses, parasites and bacteria, salinity related components, aggregate components, such as pH and solids, nutrients, organic components, including pesticides and endocrine disruptors, as well as quality variability. Relative differences in the proportion of concern for some quality characteristics were observed between the areas of different population density with those from the low population areas being more concerned than those from medium or high areas. Some users and providers observed changes in recycled water quality during distribution including nutrients, chlorine, solids, colour and odour. Some 52% of providers and 19% of current users propose to expand their usage and 30% of non-users propose to commence doing so in the next 5 years. Recycled water quality characteristics identified for applied research included microbiological components, organic components, nutrients and salinity.

Condominium developments in maturing destinations: potentials and problems of long-term sustainability

Since the emergence of mass tourism, destinations are constantly faced with the challenge of providing an adequate supply of suitable accommodation. The introduction of condominium style accommodation seemed to be the answer to the problem of meeting the increasing tourism demand at some popular destinations, although in some destinations investment in property development has increasingly become a supply driven activity. However, the resulting complexities brought about by the many stakeholders involved in managing the condominiums (including strata title legislation, investment incentives, and long-term maintenance of condominium developments) have introduced previously unforeseen problems to destinations reaching maturity. This study investigates the impacts of the growth of condominium developments and their potential for inhibiting destination rejuvenation. The study was conducted on Australias Gold Coast, a classic example of a mass tourism resort where ironically, the growth of condominium style accommodation was a major factor in attracting large numbers of tourists, but may, in fact, prevent successful rejuvenation in the future.

Copper and sewage inputs from recreational vessels at popular anchor sites in a semi-enclosed Bay (Qld, Australia): Estimates of potential annual loads

Environmental impacts of vessels are well documented; Cu pollution as result of Cu based antifouling paints and nutrient pollution (such as N) from marine sewage are two examples of such disturbances. Understanding environmental impacts as well as the use of coastal waterways by recreational vessels is of concern to regulatory authorities, waterway users and local residents. In this study more than 55 aerial surveys were conducted of selected popular anchorages in eastern Moreton Bay, Queensland, Australia. Numbers of recreational vessels at certain times during the year were used in multiple linear regression analyses to develop predictive models for recreational vessel numbers. Over one year approximately 10,000 locally registered recreational craft (>6m length overall) generated an estimated 59,000 vessel nights. With Cu leaching rates from the literature, and estimates of sewage inputs (assuming little or no use of pump-out facilities), load estimates associated with overnight use of 20 popular anchor sites were calculated as 141+/-46 kg of Cu and 1.17+/-0.38 t of nitrogen (N) annually. More importantly, the models showed vessel activity to be highly variable, and focused at peak holiday times, with 14% of vessel activity and associated pollutant loads entering the environment during Christmas and Easter. This study highlighted the inherent difficulties in managing a popular maritime amenity and Marine Parks such as the Moreton Bay Marine Protected Area, Queensland, Australia with its variety of stakeholders and types and intensities of uses.

Greenhouse Gas Emissions from Marine Tours: A Case Study of Australian Tour Boat Operators

This paper estimates the overall and per capita energy costs and GHG contributions associated with tour boat operations in Australia, a country with a 35,000 km coastline and world class marine attractions. Using a comprehensive database of Australian tour boat operators, 145 face-to-face interviews or completed postal survey questionnaires and 45 in- situ audits, the overall GHG emissions for this industry sector was estimated conservatively at 70,000 tons CO2-e or 0.1% of the transport sector in Australia, the fastest growing sector in terms of GHG outputs. On average, this translated into an extra 61 kg CO2-e per tourist if their travel itineraries included a trip on a boat with a diesel engine, or 27 kg CO2-e for a trip on a boat with a petrol engine – the equivalent of a single person driving 140 km or 300 km, respectively, in a standard passenger vehicle. Information obtained from Australian tour boat operators, however, indicated a range of technical and operational opportunities for reducing GHG emissions. In the light of Australia’s anticipated growth in domestic and international visitors, the importance of reducing tour boat GHG outputs, is stressed.

Uncertainty analysis in the application of multi-criteria decision-making methods in Australian strategic environmental decisions

Multi-criteria decision-making techniques have become increasingly widespread in strategic environmental decision making. In Australia, these techniques are used to integrate both conservation and development aspects of natural resource use. MCDM can also evaluate the effects of uncertainties at each stage of the decision-making process and examine the sensitivity of results to the inputs. This paper reviews the potential uncertainties in environmental management decision-making procedures and explores how uncertainty analysis in the framework of MCDM can address some of these uncertainties. It then examines the application of MCDM in 16 Australian case studies to determine how uncertainty has been addressed in practice. Results demonstrate that appropriate use of MCDM can address uncertainties associated with decision-makers’ preferences and from using different techniques (epistemic uncertainty). Results also highlighted the need for incorporating visualising techniques, such as GIS and simulation algorithms (e.g. Monte Carlo simulations), to examine the effects of uncertainty on the spatial pattern of the outcomes. This approach also presents promising ways to gain an understanding of the effects of some dimensions of stochastic uncertainty, and assists in increasing the transparency of the decision-making process.

How Property Title Impacts Urban Consolidation: A Life Cycle Examination of Multi-title Developments

Continuing urbanisation is triggering an increase in multi-titled housing internationally. This trend has given rise to a substantial research interest in the social consequences of higher density living. Fewer enquiries have been directed to examining how property title subdivisions generate social issues in multi-titled housing. This is a significant gap in the literature, as the tensions inherent in multi-title developments have significant implications for individuals, developments and entire metropolitan areas. This article employs a life cycle framework to examine the profound operational and governance challenges that are associated with the fusion of private lot ownership with common property ownership. The article calls for a more explicit recognition of these challenges by academics, policymakers, practitioners and the broader community.

Funding common property expenditure in multi-owned housing schemes

Purpose – The purpose of this paper is to advance a set of criteria for appraising the merits of alternative options to financing common property capital expenditure in multi‐owned housing (MOH) complexes and to then draw on this conceptual framework to determine which mode of common property capital expenditure funding is preferable.Design/methodology/approach – A priori reasoning has been provided to pursue the studys objective.Findings – Sinking funds represent the preferred approach to financing common property expenditure in MOH schemes and special levies are the least preferred approach.Research limitations/implications – Due to the a priori based conceptual development undertaken, some subjectivity is bound to be invoked.Practical implications – The study provides key insights to government policy makers charged with drafting MOH legislation and provides strong support for those jurisdictions that require sinking funds to be raised in MOH complexes. The study also informs the owners executive comm...

Investigating three-dimensional mesoscale habitat complexity and its ecological implications using low-cost RGB-D sensor technology

Summary 1. Structural complexity, that is, spatial patterns of structural ‘units of interest’, is one of the most fundamentaldrivers in habitat use of animals and other functions of h abitats. Assessment of habitat structural complexity(e.g. mangrove root complexity) and its ecological implic ations (e.g. mangroves as nursery sites) has, however,been hampered by the lack of satisfactory methods for rea listically measuring and analysing field habitat struc-ture.2. We demonstrate a simple low-cost approach comprising anRGB_D scanning sensor (Kinect), free andread-ilyaccessiblesoftware(Meshlab,Matlab (orOctave),Qub icleConstructorandVoxeliser)andfractaldimensionto measure mangrove root structure and complexity at spa tial scales relevant to juvenile fish use of the habitat.The cube-counting method was used for three-dimensional characterisation of fractal dimensions of spacearound aerial roots of mangroves from a ‘fish point of view’. Space –fish relationship under different ecologicalsituationswasassessedbysimulatingafallingtideandusin gdifferentrectangularprismstorepresentvaryingfishallometriesutilizingthespace.3. Fractal dimension (FD) of space around roots decrease d with decreasing height of the ‘object’ mimicking afalling tide. The same root system may therefore look m ore complex to aquatic animals as the water leveldecreases. We also assessed the variation in FD responding to manipulation of the density and arrangement ofobjects (pneumatophores). Difference in FD was genera lly small, due attention to replication is necessary forcomparisonsofhabitatstructuralcomplexityusingthismetric.4. This simple low-cost approach willenable field measurements ofhabitatstructure at spatialscales relevant toitsinfluenceonhabitatuseandanimalbehaviour,aswellas allowingrealisticreplicationoffieldstructureforlab-oratory-basedexperiments.

Assessment of sea‐level rise adaptation options: Multiple‐criteria decision‐making approach involving stakeholders

Purpose – The Gold Coast is a low‐lying coastal Australian city and many residential areas are subject to 1:100 year flood events. Evidently, there is a need for the city to adapt to sea‐level rise (SLR) by developing more effective policies to reduce its destructive impacts. Thus, the purpose is to identify and evaluate preferred adaptation alternatives to reduce the vulnerability to SLR and storm surges.Design/methodology/approach – In this research, we explore stakeholders’ opinions for adaptation alternatives to adapt to the impacts of SLR. As part of exploring alternatives to improve Gold Coasts resilience to climate change effects we are undertake a multi‐criteria analysis by using the analytical hierarchy process (AHP). The goal, criteria and adaptation alternatives were derived, and based upon, adaptation programmes, existing adaptation works by local governments and an extensive literature review. The final AHP structure was developed after further consultations with three local stakeholders (po...