Flow conditions, bed form dimensions and shear stress experiments

Large asymmetric bed forms commonly develop in rivers. The turbulence associated with flow separation that develops over their steep lee side is responsible for the form shear stress which can represent a substantial part of total shear stress in rivers. This paper uses the Delft3D modeling system to investigate the effects of bed form geometry and forcing conditions on flow separation length and associated turbulence, and bed form shear stress over angle-of-repose (30 lee side angle) bed forms. The model was validated with lab measurements that showed sufficient agreement to be used for a systematic analysis. The influence of flow velocity, bed roughness, relative height (bed form height/water depth), and aspect ratio (bed form height/length) on the variations of the normalized length of the flow separation zone, the extent of the wake region (where the turbulent kinetic energy (TKE) was more than 70% of the maximum TKE), the average TKE within the wake region and the form shear stress were investigated. Form shear stress was found not to scale with the size of the flow separation zone but to be related to the product of the normalized extent of the wake region (extent of the wake region/extent of water body above the bed form) and the average TKE within the wake region. The results add to understanding of the hydrodynamics of bed forms and may be used for the development of better parameterizations of smallscale processes for application in large-scale studies.

Disciplining Investment Incentives: A Lost Cause?

An E15 Initiative think piece: Investment incentives rank among the most important policy instruments governments employ to influence the locational decisions of multinational firms. In the wake of the recent increase in locational competition and the growing impact of investment incentives and support measures for state-owned enterprises (SOEs), the need for enhanced disciplines on investment incentives has gained political and academic salience. This think piece explores the evolution of investment incentives from a development and rule-making perspective. It summarises the existing literature and examines current practices and recent trends in FDI flows and the use of various investment incentives. This is followed by a discussion of the reasons for the observed stalemate in attempts at disciplinary rule-making. The paper concludes by putting forth recommendations for data gathering and transparency that could further the move toward improved global governance founded on the increasing complementarities of trade, investment, and competition law and policy as the core pillars of a more open, inclusive, and just world economy.

Development of Border Economic Zones in Thailand: Expansion of Border Trade and Formation of Border Economic Zones

In the wake of economic globalization and development in Thailand, movement of people and commodities at the Thai borders is also becoming pronounced. Economic interdependence between Thailand and neighboring countries is growing through border customhouses. As a policy, Thailand is trying to stimulate trade and investment with neighboring countries following the ACMECS (Ayeyawady-Chao Phraya-Mekong Economic Cooperation Strategy) scheme. In this report, first, movement of people and goods at the borders will be examined. Second, clarification of where and how development is proceeding will be presented. Last, this study will attempt to review the perspectives of policies on neighboring countries after Thaksin.