Resuspension of sediment-associated Escherichia coli in a natural stream

In this study, a tracer bacteria was used to investigate the resuspension and persistence of sediment-associated bacteria in a small alluvial stream. The study was conducted in Swan Creek, located within the Grand River watershed of Ontario, Canada. A 1.1-m2 section of the bed was seeded with a strain of Escherichia coli resistant to nalidixic acid (E. coli NAR). The survival, transport, and redistribution of the tracer bacteria within a 1.7-km river section downstream of the source cell was assessed for a 2-mo period following the introduction of the tracer bacteria. This study has illustrated that enteric bacteria can survive in bed sediments for up 6 wk and that inactivation of the tracer bacteria resembled typical first-order decay. Critical conditions for resuspension, as well as resuspension rates, of sediment-associated bacteria were determined for several storm events. The critical shear stress for E. coli NAR resuspension in Swan Creek ranged from 1.5 to 1.7 N m(-2), which is comparable with literature values for critical shear stresses for erosion of cohesive sediments. Bacteria resuspension was primarily limited to the rising limb of storm hydrographs implying that a finite supply of sediment-associated bacteria are available for resuspension during individual storm events. The information presented in this paper will further the development of representative microbial water quality models.     

Laboratory development and field demonstration of self-sealing/self-healing landfill liner

The self-sealing/self-healing (SS/SH) barrier concept is based on the principle that two or more parent materials placed in vertical or horizontal layers will react at their interfaces to form insoluble reaction products. These products constitute a seamless impermeable seal, which is resistant to the transmission of leachate and contaminants. A SS/SH liner formulation was developed in the laboratory and demonstrated at the Sudokwon landfill site in South Korea. Laboratory testing results indicated that a seal with a hydraulic conductivity less than 10(-9) m/s formed after two to four weeks of curing at room temperature, and the seal healed itself after it was fractured. The use of the soil from the Sudokwon landfill site instead of sand as the matrix of the parent materials in the SS/SH liner retarded the sealing and healing of the seal, but did not show an obvious effect on the overall sealing and healing capacity of the seal at early stages. The construction and installation of the field demonstration SS/SH liner were carried out in the same way as for a soil cement liner. The quality of the liner was ensured by the enforcement of quality analysis/quality control procedures during installation. A single sealed ring infiltration test was performed on the field demonstration liner 36 days after the installation was completed. The measurement of water infiltration rate indicated that the liner healed after it was fractured. However, the long-term sealing and healing capacity needs to be further investigated.     

Radon (222Rn) level variations on a regional scale: influence of the basement trace element (U, Th) geochemistry on radon exhalation rates

The approach proposed in this study provides insight into the influence of the basement geochemistry on the spatial distribution of radon (222Rn) levels both at the soil/atmosphere interface and in the atmosphere. We combine different types of in situ radon measurements and a geochemical classification of the lithologies, based on 1/50,000 geological maps, and on their trace element (U, Th) contents. The advantages of this approach are validated by a survey of a stable basement area of Hercynian age, located in South Brittany (western France) and characterized by metamorphic rocks and granitoids displaying a wide range of uranium contents. The radon source-term of the lithologies, their uranium content, is most likely to be the primary parameter which controls the radon concentrations in the outdoor environment. Indeed, the highest radon levels (> or = 100 Bq m-3 in the atmosphere, > or = 100 mBq m-2 s-1 at the surface of the soil) are mostly observed on lithologies whose mean uranium content can exceed 8 ppm and which correspond to peraluminous leucogranites or metagranitoids derived from uraniferous granitoids.     

Residents’ Assessment of an Urban Outdoor Water Conservation Program in Guelph,Ontario1

Abstract: Many municipalities have implemented demand management of outdoor water use. Measures such as restrictions on lawn watering and promotion of xeriscaping are effective in reducing water demand during summer months, especially during dry spells. However, little research examines a key factor shaping the success of these programs: residents’ perceptions of and satisfaction with such conservation measures. This article describes an urban outdoor water conservation program in Guelph, Ontario, assesses that program from the perspective of residents, and explores socio‐economic, attitudinal and other factors associated with residents’ assessment of the program. A survey of Guelph residents revealed broad support for the program, which includes restrictions on various outdoor water uses and, under certain circumstances, a ban on lawn watering. However, there was much uncertainty among residents about the effectiveness of the program in reducing water use and the effectiveness of program enforcement. Key factors influencing residents’ assessment of the program were neighborhood, gender and environmental attitude. Implications for the design and implementation of outdoor water conservation programs are discussed, including the importance of better communication of information on program effectiveness and enforcement.     

Climate change adaptation planning in agriculture: processes,experiences and lessons learned from early adapters

This paper explores the lessons learned by leaders in agricultural adaptation planning in order to assist other jurisdictions to develop adaptation strategies. It seeks to identify effective institutional, participatory and collaborative processes involved in designing agricultural adaptation strategies at the national and sub-national levels in Germany, Finland, the United Kingdom, the United States and Canada. Its methodology is based on review of agricultural adaptation policy documents, research initiatives, stakeholder engagement processes, and cross-sectoral collaborations as well as interviews with key informants such as leaders and actors in adaptation planning. The gathered data show that early adapters have an improved regional and national understanding of climatic impacts, and of the risks to agriculture before the initiation of the planning process. The results indicate that the interplay between bottom-up and top-down initiatives has been crucial in the development of adaptation strategies. The former has provided rich and robust participation in designing, implementing and monitoring adaptations, while the latter was important for prioritizing and legitimizing the development of strategy. It also provided access to high-level decision makers and funding. The results of the study suggest that fostering cross-sectoral collaborations—especially by focusing on broader questions such as the role of agriculture in society—has become an important part of adaptation planning. Finally, our results also stress that adaptation planning in agriculture could be enhanced by skills development and mutual learning across stakeholder groups, research and policy-makers, and through the ongoing interactive development of institutional capabilities.     

Strategic Niche Management in an unstable regime: Biomass gasification in India

This paper analyses the development and implementation of biomass gasifiers in India. Based on literature reviews and fieldwork, an historical narrative is presented starting with laboratory experiments in the 1980s up to commercial applications after 2000. This narrative is analysed using the Strategic Niche Management framework. We conclude with the benefit of hindsight that technological expectations where generally too high. The biomass gasification technology is not easy to design and operate and needs to be embedded in a stable institutional set up to allow learning, knowledge transfer, regulation and funding. We also conclude that, in contrast with theoretical predictions, up-scaling the niche suffers from regime instability rather than regime stability, as there is a need to give more security to investors and end-users. For instance through setting clear and long-term condition for grid-connected biomass gasification systems and feed-in schemes. Up-scaling through local off-grid applications where enough technical competence is available is the most likely trend in the near future.     

Biomass energy experiments in rural India: Insights from learning-based development approaches and lessons for Strategic Niche Management

This paper investigates the suitability and limitations of the Strategic Niche Management framework in the context of emerging economies of South and East Asia. We explore several learning-based approaches to development projects that are part of the academic and practitioner field of development studies. The approaches show similarities with SNM but they reflect the developing-country context within which they were framed, and are also more geared towards local community development and capacity building. We apply these approaches to four biomass energy projects in rural India to identify determinants of success and failure. We then discuss how these findings compare with the insights that an SNM analysis would have offered. We arrive at the following conclusions. First, the great strengths of SNM are its explicit conceptualisation of environmental sustainability and its endogenous treatment of the larger context. Second, the learning-based development approaches hone in on the complexities of local management and stakeholder organisation. Third, they also bring out the great importance of local institutions such as traditional status and power differences. Fourth, we conclude that SNM holds considerable promise for application in a developing Asian context, but that its usefulness and relevance in that setting could be enhanced by incorporating these additional issues.     

Sustainability experiments in Asia: innovations shaping alternative development pathways?

Global sustainability is increasingly influenced by processes of industrialisation and urbanization in non-OECD countries, especially in Asia. Growth models suggest that developing economies and regions will become first relatively more resource- and pollution-intensive, before converging on more resource-efficient and low-pollution production and consumption patterns expressed in developed countries. Alternative less resource- and pollution-intensive growth models for latecomer countries promise social and economic benefits in the short- and long-term. Drawing on insights from system innovation research on long-run change in socio-technical systems, we discuss the potential role of ‘sustainability experiments’ to generate innovations that will constitute new ‘greener’ growth models. We observe a great number of technology-based initiatives that we characterize as sustainability experiments in East and South Asian countries. These experiments emerge in the context of the growth of new socio-technical regimes in key sectors, including energy, transport, manufacturing, food and the built environment. We set out a conceptual framework for assessing the role of experiments, and for evaluating how they link with and become anchored into alternative more sustainable regimes. In this paper we argue that sustainability experiments represent a significant new source of innovation and capability-formation, linked to global knowledge and technology flows, which could reshape emergent socio-technical regimes and so contribute to alternative development pathways in latecomer countries. We conclude by summarizing the six papers published in this Special Issue.     

A goal oriented indicator framework to support integrated assessment of new policies for agri-environmental systems

The goal oriented framework (GOF) for indicators has been developed as part of a comprehensive research project developing computerised tools for integrated assessment of the effects of new policies or technologies on agricultural systems (SEAMLESS-IF). The ambition has therefore been to create an indicator framework where the environmental, economic and social dimensions of sustainable development can be related to each other in a consistent way. Integrated assessment tools rely on such frameworks to capture and visualise trade-offs (antagonisms or synergies) among indicators between and within the three dimensions of sustainable development. The specific aims of this paper are to (i) present the GOF (ii) present how the GOF can be used to select indicators within the integrated assessment framework SEAMLESS-IF and (iii) discuss the advantages and limitations with the proposed approach. We show that the GOF has several advantages. Its major rewards are its relative simplicity and the possibility to link indicators to policy goals of each dimension of sustainability and thereby facilitate the comparison of the impacts of the new policy on the different dimensions. Another important feature of the GOF is its multi-scale perspective, which will enable the comparison of effects of a new policy between scales. Yet, as typical for all indicator frameworks, the GOF has also biases either instigated by the issues the included models cover or by the stakeholders’ selection of indicators. However, due to the way the GOF and its indicators are technically implemented in SEAMLESS-IF, it can easily be extended and include new indicators to increase and update its policy relevance.