Hydro-morphological alteration and related effects on fish habitat induced by sediment management in a regulated Alpine river  

作　　者：Livia Servanzi Silvia Quadroni Paolo Espa 

机构地区：[1]Department of Science and High Technology,University of Insubria,Varese,Italy [2]Department of Theoretical and Applied Sciences,University of Insubria,Varese,Italy

出　　处：《International Journal of Sediment Research》2024年第4期514-530,共17页国际泥沙研究（英文版）

基　　金：supported by the European Regional Development Fund within the Cooperation Program V-A Italy-Switzerland 2014-2020;specifically the project“Gestione risorse idriche ed ambienti aquatici in comune-Il bacino del Fiume Mera-GE.RI.KO MERA”(ID:473458).

摘　　要：Sediment pulses can cause relevant geomorphological alteration and fine sediment deposition,affecting the entire river ecosystem.Quantifying the impact of these events is becoming increasingly important,as sediment disturbance is predicted to intensify because of growing anthropogenic activity combined to the effects of current climate change.In this paper,the effects of a sediment pulse event on riverbed morphology and,in turn,on fish habitat availability are assessed in a regulated river,located in the southern European Alps.Specifically,four target fish species were selected:marble(Salmo marmoratus)and brown trout(Salmo trutta),grayling(Thymallus thymallus),and bullhead(Cottus gobio).The investigated event was triggered by the effects of localized landslides combined with an uncontrolled sediment release from a hydropower reservoir.A pre-post event integrated approach was applied,involving topographic surveys,fine sediment deposition measurements,and eco-hydraulic modeling.Habitat availability analysis was done using two-dimensional steady-state channel-flow simulation and standard habitat suitability modeling,with univariate suitability curves as biological input.The investigation focused on two river reaches,quite close each other,but characterized by significantly different streamflow patterns,due to the layout of the local hydropower system.The results showed that noticeable riverbed fining occurred at both study reaches after the pulse,with the maximum thickness of the fine sediment deposits up to one meter,and higher amounts of deposition detected in areas wetted at baseflow.Moreover,for both reaches,recovery to the pre-event riverbed grain-size condition occurred in about a year,but with differences related to different streamflow patterns.Pre-post topographic comparison showed that areas of erosion prevailed over areas of deposition,and fine sediment deposition was not systematically associated to the riverbed elevation raise.Simulated habitat availability was affected by both topographic changes and f

关 键 词：Sediment pulse Fine sediment deposition Topographical changes Riverbed substrate Habitat suitability HYDROPEAKING 

分 类 号：TV14[水利工程—水力学及河流动力学]