The Use of Evolutionary Trajectories to Guide ‘Moving Targets’ in the Management of River Futures

Abstract

AbstractRiver histories provide important guidance with which to inform river management. Evolutionary trajectories and appraisals of system responses to changing flux conditions and disturbance events can be used to determine the range of potential future states and associated behavioural regimes, assessing the likelihood that that these states will be attained over a given timeframe. In these analyses, natural or historical reference reaches may not provide a realistic basis to set target conditions for management actions, as what has gone before does not necessarily provide a complete and reliable picture of prospective future conditions. This paper outlines the use of a conceptual tool, the river evolution diagram, as a geomorphic platform to assess river history and the potential range of river futures for any given system. Evolutionary adjustments of a sand bed river in southeastern Australia are used to demonstrate the application of this approach. Applying adaptive management principles, ‘moving targets’ for river management are framed in relation to the range of likely future states and trajectories of adjustment. Copyright © 2015 John Wiley & Sons, Ltd.