Braided River Management: from Assessment of River Behaviour to Improved Sustainable Development

Braided rivers change their geometry so rapidly, thereby modifying their boundaries and floodplains, that key management questions are difficult to resolve. This paper discusses aspects of braided channel evolution, considers management issues and problems posed by this evolution, and develops these ideas using several contrasting case studies drawn from around the world. In some cases, management is designed to reduce braiding activity because of economic considerations, a desire to reduce hazards, and an absence of ecological constraints. In other parts of the world, the ecological benefits of braided rivers are prompting scientists and managers to develop strategies to preserve and, in some cases, to restore them. Management strategies that have been proposed for controlling braided rivers include protecting the developed floodplain by engineered structures, mining gravel from braided channels, regulating sediment from contributing tributaries, and afforesting the catchment. Conversely, braiding and its attendant benefits can be promoted by removing channel vegetation, increasing coarse sediment supply, promoting bank erosion, mitigating ecological disruption, and improving planning and development. These different examples show that there is no unique solution to managing braided rivers, but that management depends on the stage of geomorphological evolution of the river, ecological dynamics and concerns, and human needs and safety. For scientists wishing to propose ‘sustainable’ solutions, they must consider the cost-benefit aspects of their options, and the needs and desires of society. This requires an interdisciplinary approach linking earth scientists and social scientists concerned with environmental economics, planning, and societal and political strategies, in order to fully evaluate the economic and social validity of different options for different time-scales.

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