Defining conservation objectives in river restoration: the river disorder approach

The manifestation of the river system is the result of an array of discontinuous, non-equilibrium processes operating at different scales, influenced by the constellation of geographic, hydro- and bio-ecoregions in the river basin. We propose a multidimensional and multiscale approach to define conservation objectives for river ecosystems. The River Disorder Approach provides a framework for deriving objectives from observed patterns and structures in the river system, resulting from the discontinuous processes among the various temporal and spatial scales. We identified disorder elements for the River Meuse at the different scale levels for the floodplain meadows and immediately derived conservation objectives from it. These where then integrated in a guiding image, to prove the practicability of this approach.
Contrasting with the common view of rivers as continuous and self-repeating in components and patterns, we identified the non-equilibrium and stochastic processes as guiding for the definition of conservation objectives. This choice conflicts with presently used deterministic approaches. As this type of deterministic approaches is used for generalized goal setting for rivers in national or even pan-European legislative frameworks, but encounters strong problems, our plead for idiosyncratic, non-deterministic target setting might prove helpful for the implementation of river basin management.