Suchergebnisse

There have been attempts to simulate meander dynamics (Langbein and Leopold 1966, Oodgard 1989, Campoerale et. al 2007, da Silva and El-Tahawy 2008, Duan and Julien 2010, Blanckaert and de Vriend 2010, Esfahani and Keshavarzi 2011). Meandering geometry is complex phenomena (Chanson 2004, Wu 2008), this would include the dynamics of flow properties and of morphology. Simulating meander flow dynamics is mostly popular using either Finite Element Method (FEM) or Finite Volume Method (FVM) where are based on Eulerian description, and based on stationer grid-based methods (Wormleaton and Ewunetu 2006, Wu 2008, Duan and Julien 2010, Gomez-Gesteira et. al 2010). As such this model is lack of capability in simulating the dynamics of meander morphology; much effort is put through to overcome this issue with such as Smoothed Particle Hydrodynamics (SPH), Boundary Element Methods, Arbitrary Lagrangian Eulerian, etc. This paper has two objectives; to identify meander flow characteristics and sediment transport distribution patterns, and to simulate meander flow characteristics and sediment transport distribution patterns using FEM. This study has identified that the key of dynamics of flow characteristics are helical flow and coherent structures, and the key of dynamics of transport characteristics are erosion-deposition zone patterns. The finite element model using in this study, RMA has shown its capability to simulate the meander key characteristics above, for small deflection angles (30°) location of maximum erosion-deposition zones near the crossover of the sinuosity, for intermediate deflection angles (70°) location of maximum erosion-deposition zones between the crossover and apex of the sinuosity, and for large deflection angles (110°) location of maximum erosion-deposition zones near the apex of the sinuosity, these are agreed with experiments of Odgaard 1989, da Silva 2006, da Silva et. al 2006, and Esfahani and Keshavarzi (2012). These results can be used as a reference to develop a method to model meander morpho-dynamics.

Nature Based Solutions (NBS) are increasingly used for improving water quality, reducing urban flooding and providing ecological and amenity benefits. Although predominantly developed and implemented in industrialised countries, NBS are gaining traction in the Global South. Strategic planning is required to deliver the anticipated benefits and ensure successful integration into urban landscapes. Spatial software and planning support systems (PSS), can inform such decision-making. We seek to understand the efficacy of utilising PSS for advancing NBS practices within Indonesian urban settings. Through workshops and in-depth interviews with urban planning practitioners, we examined (i) the current NBS planning context, (ii) tacit experiences with contemporary PSS, and (iii) potential utility of PSS to address identified challenges with NBS planning. While strategic planning processes were perceived as improving over past decades, significant challenges remain including inadequate collaboration between actors, insufficient capacity and resources of local governments and limited access to high-quality spatial data. Although strategic planners employ contemporary PSS, further embedding those into decision-making processes requires rethinking the socio-institutional and political context within which they operate. Results revealed keen interest to adopt innovative PSS. However, without access to high-quality spatial information, strategic planning will continue to be compromised, potentially leading to illsited NBS interventions. ; ISSN:0264-2751