Channel response of an engineered river to climate change and human intervention

Abstract

Humans have intervened in rivers for centuries. River engineering measures have aimed at protecting populations against flooding, ensuring reliable and safe navigation, providing freshwater for drinking, domestic and industrial use, irrigation, and energy supply, and providing opportunities for recreation. All around the world, measures such as channelization (i.e., channel narrowing and shortening), dam construction, or channel diversion have allowed for the proliferation of human settlements, technological progress, and an improved quality of life.
Despite the various socio-economic benefits of human intervention in rivers, engineering measures have side effects, often unaccounted for, or simply unknown before they manifest. This is because, by modifying the channel characteristics (geometry, planform, size of the bed surface sediment), or its controls (water discharge, sediment supply, base level), engineering measures alter the equilibrium state of a river. In response, rivers adjust toward the new equilibrium state through bed incision or aggradation, changes in channel width or sinuosity, or changes in the bed surface grain size distribution. This response may extend over hundreds of kilometers, and develop during decades to centuries....