Understanding changing riverine landscapes: instability, thresholds, and tipping points

Riverine landscapes are dynamic systems’ is a mantra of the river science community. Studies of changing river systems have a history extending to W.M. Davis and G.K. Gilbert. Despite progress towards an understanding of change as a fundamental property of river systems, the bewildering array of terms, models and views about the role and significance of river system behaviour does not enable disciplinary cohesiveness. This is further compounded by the increasing influence and intensity of human activities. A framework for navigating change in river systems is presented in this chapter, along with a discussion of some concepts of river system change. Three case studies provided from Australia, New Zealand and the United States illustrate the importance of understanding different drivers of change, the nature of riverine landscape upon which these drivers act and the complex response of interactions. The emergence of interdisciplinary perspectives of change, fostered by resilience thinking, is likely to arise from viewing riverine landscapes in the context of regime shifts at multiple scales. These efforts should contribute to improved scientific understanding and stewardship of riverine landscapes.