Response of the Dnieper river fluvial system to the river erosion caused by the operation of the Kaniv hydro-electric power plant (Ukraine)

摘要: Abstract The commission of the Kaniv dam in 1973, as last six dams on lower Dnieper River cascade, changed river regime completely. A description these changes and their impact evolution fluvial anastomosing system form aims study. operation hydroelectric power plant (HPP) significantly affected erosion accumulation sediment valley floor thus below dam. HPP initially operated a hydropeaking (until early 1990s) then run-of-river system. This study used indicators hydrologic alteration (IHA), RB flashiness index, archival topographic bathymetric maps, hydrological sedimentological field studies, satellite images to assess how magnitude duration flow processes bed pattern channels well landforms separating them. Until Kaniv, its undisturbed state was sand-bed channel but transformed from braiding an achieved by bars where consolidation vegetation fine clastic deposits created interchannel areas islands. During system, characterised frequent artificial flows short duration, became incised narrowed. Interchannel were divided up into Then, after switched working islands began merge again areas. happened result intensified both main side channels. HPP, changing sedimentation valley, modified natural process River.