Channel forms and vegetation adjustment to damming in a Mediterranean gravel-bed river (Serpis River, Spain)

This paper focuses on the analysis of changes observed in channel morphology in the Serpis River (Alicante, Spain), a gravel-bed river dammed since 1958. The paper analyses flow series and several aerial images, prior and subsequent to dam construction, to analyse changes in channel morphology and vegetation colonisation using Geographical Information Systems (GIS) techniques. Results show a concatenation of morphological changes throughout an adjustment sequence (60 years), which started with the transformation from wandering to single thread channel pattern, was followed by a slow vegetation encroachment, and culminated with the stabilization of channel migration. The role of vegetation (particularly Salicaceae species) has been critical in controlling floods' effectiveness, reducing river mobility and shifting, and consolidating a channel planform model adapted to the post-dam flow conditions.