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Rapid urbanisation generates risks and opportunities for sustainable development. Urban policy and decision makers are challenged by the complexity of cities as social–ecological–technical systems. Consequently there is an increasing need for collaborative knowledge development that supports a whole-of-system view, and transformational change at multiple scales. Such holistic urban approaches are rare in practice. A co-design process involving researchers, practitioners and other stakeholders, has progressed such an approach in the Australian context, aiming to also contribute to international knowledge development and sharing. This process has generated three outputs: (1) a shared framework to support more systematic knowledge development and use, (2) identification of barriers that create a gap between stated urban goals and actual practice, and (3) identification of strategic focal areas to address this gap. Developing integrated strategies at broader urban scales is seen as the most pressing need. The knowledge framework adopts a systems perspective that incorporates the many urban trade-offs and synergies revealed by a systems view. Broader implications are drawn for policy and decision makers, for researchers and for a shared forward agenda.

This paper presents a critical review of the physical impacts of decentralized water supply systems on existing centralized water infrastructures. This paper highlights the combination of centralized and decentralized systems, which is referred to as hybrid water supply systems. The system is hypothesized to generate more sustainable and resilient urban water systems. The basic concept is to use decentralized water supply options such as rainwater tanks, storm water harvesting and localized wastewater treatment and reuse in combination with centralized systems. Currently the impact of hybrid water supply technologies on the operational performance of the downstream infrastructure and existing treatment processes is yet to be known. The paper identifies a number of significant research gaps related to interactions between centralized and decentralized OPEN ACCESSWater 2015, 7 154 urban water services. It indicates that an improved understanding of the interaction between these systems is expected to provide a better integration of hybrid systems by improved sewerage and drainage design, as well as facilitate operation and maintenance planning. The paper also highlights the need for a framework to better understand the interaction between different components of hybrid water supply systems.

Based on "Sapkota, M.; Arora, M.; Malano, H.; George, B.; Nawarathna, B.; Sharma, A.; Moglia, M. Development of a framework to evaluate the hybrid water supply systems. In Proceedings of the 20th International Congress on Modelling and Simulation, Adelaide, Australia, 1-6 December 2013". Abstract:Urban water managers around the world are adopting decentralized water supply systems, often in combination with centralized systems. While increasing demand for water arising from population growth is one of the primary reasons for this increased adoption of alternative technologies, factors such as climate change, increased frequency of extreme weather events and rapid urbanization also contribute to an increased rate of adoption of these technologies. This combination of centralized-decentralized water systems approach is referred to as "hybrid water supply systems" and is based on the premise that the provision of alternative water sources at local scales can both extend the capacity of existing centralized water supply infrastructures, and improve resilience to variable climatic conditions. It is important to understand, however, that decentralized water production and reuse may change the flow and composition of wastewater and stormwater, thereby potentially also having negative impacts on its effectiveness and performance. This paper describes a framework to assess the interactions between decentralized water supply systems and existing centralized water servicing approaches using several analytical tools, including water balance modelling, contaminant balance modelling and multi-criteria decision analysis. The framework enables the evaluation of impacts due to change in quantity and quality of wastewater and stormwater on the existing centralized system arising from the implementation of hybrid water supply systems. The framework consists of two parts: (1) Physical system analysis for various potential scenarios and (2) Ranking of Scenarios. This paper includes the demonstration of the first part of the framework for an area of Melbourne, Australia by comparing centralized water supply scenario with a combination of centralized water supply and reuse of treated waste water supply scenario.

A common and driving assumption in agricultural research is that the introduction of research trials, new practices and innovative technologies will result in technology adoption, and will subsequently generate benefits for farmers and other stakeholders. In Lao PDR, the potential benefits of introduced technologies have not been fully realised by beneficiaries. We report on an analysis of a survey of 735 smallholder farmers in Southern Lao PDR who were questioned about factors that influenced their decisions to adopt new technologies. In this study, we have constructed measures or states of adoption which identify key elements of an adoption decision-making nexus. Analysis was conducted to statistically group explanatory factors of adoption. The key explanatory factors represented attributes of the farmer, the factors considered when undertaking production decisions and elements of the agricultural value chain that present as opportunities or constraints. We describe the combination of farmer's personal attributes, perceptions of the value chain, and the introduction of new technologies by external actors as an "agricultural research value chain", where agricultural research activities intervene to derive greater benefits for local farmers. A generalised linear model, via Poisson (multiple) regression analysis on the identified explanatory factors, was applied to explore how they influence adoption measures and we found several significant relationships.