Meander chute cutoff at an alluvial river facilitated by gypsum sinkholes

Collapse sinkholes are common in areas where gypsum strata underlie rock that is incompetent to bridge the cavities created by groundwater dissolution of gypsum. On floodplains these can be obscured due fill overbank deposits, and channels tend migrate towards larger enclosed depressions. This study utilises GIS analyse influence exerted small collapse on channel dynamics alluvial River Ure, UK. At Ripon Loop, a large compound meander bend, sinkhole area have been tracked over >160 years from multiple datasets, including historic maps, aerial imagery, lidar Structure-from-Motion photogrammetry dataset acquired for this study. indicated two distinct populations, firstly long-lived, constant-sized secondly dynamically growing holes aligned with contact bedrock unconsolidated materials buried valley at depth artesian water saturated sulphate enters latter. Frequent flows Ure across neck bend interacted sinkholes, e.g. deposition bedload down-valley end localised headward incision opposite side relatively high gradient between downstream limb. The location has conditioned shallow least 7 years, before cutoff occurred several floods 2019. Initially flow traversed via chain widening deepening captured all surface resulting mobilisation more than 20,000 m3 sediment. Allogenic influences fluvial systems relation often neglected first link floodplain detailed mechanisms chute cutoff, hereby indicating potential feedback processes.