Mise en place des îles fluviales en Loire moyenne, du 19e siècle à aujourd’hui

Downstream of the confluence with the Allier River, the Middle Loire River is characterized by a fluvial bed with semi-embanked channel. The wooded islands are ubiquitous throughout the river’s landscape, and are areas of active vegetalization in the fluvial bed. The aim of the present paper is to provide an update to the current knowledge of these fluvial forms: their formation and rate of development. Recent development of anabranching in the Loire river is related to the co-evolution of societal uses, and the morphology of the river bed. The main channel of the river has continued to migrate laterally within its area of mobility. This situation has led to the development of large areas of sedimention on the biggest islands, which play a major role in the retention of sediments, and the sedimentary imbalance of the river. The development of anabranching reveals fluvial readjustments, and the islands are excellent bio-geomorphological indicators. Our study provides additional input to current research on the anastomosis of rivers with islands in Western Europe.