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Uganda's Vision 2040 aims to modernize rural water supply through a transition from community-managed point sources to professionally managed piped water services. At the start of the transition period, a learning alliance established in Kabarole District participated in action research to develop scenarios predicting possible future development trajectories. The diversity of its membership, whose formal institutional roles spanned national, district and niche levels, increased the robustness of the strategies proposed for the adaptively managed transition of the public water service. The learning alliance has been facilitated by a non-governmental organization providing funding and expert advice; the effectiveness of this approach is demonstrated. [ABSTRACT FROM AUTHOR]

A cornerstone of feminist thinking, intersectionality offers a critical analytical tool for exploring how gender intersects with other social structures of power. However, this leaves intersectionality grounded firmly insocialanalysis. Becoming increasingly salient are the complex political and material relations between social power, infrastructure and water (Linton and Budds, 2014). Intersectionality – centring the entanglement of difference – offers an opportunity to explore the interplay between social relations and difference in the physical world (Thompson, 2016). Drawing on participatory visual research with women and men across four communities in Cameroon, we elaborate how gendered social relations intersect with the material dimensions of water and sanitation. Given gendered and age-based divisions of labour, women and girls play a primary role in household water management. This article centres on women’s concerns about everyday water access, use and control to elaborate how intersectional social dynamics in relation to water also intersect with water in the physical world. Expanding intersectional thinking beyond the social realm, we also demonstrate how gendered intersections shape and are shaped by the material and physical dimensions of water. This suggests that theorising about social difference alone risks missing how environmental factors influence different groups’ experiences of power, privilege and oppression. [ABSTRACT FROM PUBLISHER]

An ecomimetic method is developed as an innovative and transdisciplinary design approach rooted in the field of biomimetics. This new method emulates the interrelated complexity of the parts of an ecosystem with the intent to design buildings that are more efficient, effective and holistic. Ecomimetics refers to the design of buildings that mimic ecosystem processes and functions. This approach provides potential opportunities for climate change adaptation and mitigation by optimizing the use of resources in buildings. One challenge to the application of ecomimetics in architecture is the lack of systematic methods supported by scientific research, which may prevent development in this field. A theoretical basis and the initial development of an ecomimetic design method is presented, with a description of each step of the design process. Ecological systems are selected for functional properties that match architectural design goals, and then design tools are used to abstract and transfer those properties to architectural systems. The design tools integrated in the method are from the fields of ecological engineering, systems dynamics and architecture. The case of the Eastgate Center in Harare, Zimbabwe, is used to illustrate the method. [ABSTRACT FROM PUBLISHER]

A meshless method is used to simulate free-surface fluid flows containing solid particles, motivated by the need to simulate river ice dynamics problems. A smoothed particle hydrodynamics model (SPH), with an arbitrary Lagrangian–Eulerian formulation for the fluid phase, is two-way coupled with the discrete element method (DEM) for the solid phase. Validation test cases include a bouncing sphere on a level surface, a collapse of a granular column, wedge entry into still water and solids of different densities falling into still water. The computed results using the SPH-DEM model agree quantitatively with the expected behaviour in the test cases. Numerical convergence is demonstrated for the wedge entry validation case. The SPH-DEM model is then used to simulate the stability of floating ice blocks approaching a stationary cover and ice accumulation upstream of an obstruction. The results show promise to serve as a useful quantitative engineering tool. [ABSTRACT FROM PUBLISHER]

Engineers frequently use physical scale models of hydropower intakes to assess and minimize the occurrence of harmful free surface vortices. The impact of surface tension, viscosity and turbulence on the scaling behaviour of the vortices is examined here using an analytical free surface vortex model developed from measurements in a laboratory-scale hydropower intake. First, the effect of surface tension on the free surface depression is computed using a finite-difference model over a wide range of depression scales and shapes. The impact and scaling behaviour of surface tension are found to be qualitatively different depending on whether the depression is dimple- or funnel-shaped. The influence of viscosity on scaling predicted by the analytical vortex model contradicts trends recorded by previous authors, which suggests that additional processes such as turbulent diffusion may play a significant role at larger scales. Scale effects due to the interplay of viscosity and turbulence require further investigation, whereas those due to surface tension are fairly easily quantified and predicted. [ABSTRACT FROM AUTHOR]

Axially stretched free-surface vortices occur at low-head hydropower intakes under specific flow and geometric conditions. When they are sufficiently strong, they can harm performance or cause premature failure of mechanical components such as turbine blades or guide vanes. Laboratory-scale experimental models are currently used to assess the risk of vortex formation during the design phase, but uncertainty remains as to how vortex characteristics translate from the laboratory scale to the much larger scale of an actual hydropower plant. This paper proposes a semi-empirical model that roughly predicts how the approach flow and intake geometry determine the key vortex characteristics (the core radius, bulk circulation and the depth of the free surface depression). The model is developed using detailed velocity measurements of the approach flow and the flow inside the vortex in a laboratory-scale physical model, using analytical models and insights drawn from previous work. [ABSTRACT FROM AUTHOR]

Trinidad and Tobago's 1.3 million residents are provided water supply and sewerage services by a national utility whose service levels have been inadequate and deteriorating through the recent past, largely due to a lack of investment in utility infrastructure. A “willingness to pay” study assessed the degree of coverage and quality of service and the residents' willingness to accept water tariff increases for an increase in service level. Willingness to pay for change is low, below current tariffs, due to scepticism about the likelihood of change and due to the ability to cope with bad service through the pervasive use of local storage. [ABSTRACT FROM AUTHOR]