Automation Techniques in River Design

Stream restoration projects with the goals of habitat enhancement and improved flood protection for infrastructure and dwellers are not run-off-the-mill products. A multitude of restoration features and parameters determine design characteristics and the success of such projects. The role of computers in the planning processes has developed beyond drawing assistance and one-, two-, or three-dimensional hydrodynamic models. Perfect three-dimensional models with precise hydrologic, hydraulic and terrain evolution modules would simultaneously model terrain change and stream restoration features could be virtually implemented. Such models represent an ideal solution to achieve high feature sustainability and optimize an ecological utility. Alas, even though computation power is consistently increasing, it is still limited and natural process complexity requires simplifications in numerical models. Current best practices use two-dimensional (2D) hydrodynamic models and observed terrain change rates to assess hydraulic pattern created by potential stream restoration features. Latest software developments combine detrended digital terrain elevation models, 2D modeling results and flow scenarios for the partial automation of stream restoration design on a reach scale. The latest automation procedures in stream restoration planning and the identification of instream geomorphological features are herein described. However, sustainable stream restoration goes beyond the river reach scale and needs to consider large-scale landscape processes. New research efforts use manual classification of fluvial landscapes and processes for labeling the results of numerical model outputs. The labeling aims at enabling machine learning algorithms to learn landscape processes that determine the framework for stream restoration. As a result, particular stream restoration projects can be implemented as nested projects with a target utility for fluvial landscapes. This visionary study introduces a concept for nesting stream restoration and flood protection projects in a complex framework for the restitution of fluvial landscapes and fish abundance. In the future, the realization of this promising concept will take essential efforts and requires interinstitutional as well as interdisciplinary cooperation.