Modelling the impact of sand extraction from large rivers

Sand is one of the most intensely exploited natural resources and is utilized in several sectors. Fluvial environments are key sources for the excavation of such material. There is currently a lack of effective regulation of sand extraction, reliable data able to quantify rates of extraction, and quantitative understanding of the impacts of extraction on river morphology. The aim of this research is to address this knowledge gap by seeking to better understand the impact
of sand mining on rivers using numerical simulations. A 52-year river evolution scenario was considered, including 10 years of sand mining where sand is extracted from bars and floodplain areas at low flow (dry mining) and from the channels (wet mining). Dry mining was found to promote more dynamic responses with higher braiding and avulsion. In contrast, wet mining favors bed incision leading to less dynamic behaviors and reduced braid intensity, especially in post-mining periods.