{"title":"高寒河流泥沙管理引起的水文形态变化及其对鱼类生境的影响","authors":"","doi":"10.1016/j.ijsrc.2023.10.001","DOIUrl":null,"url":null,"abstract":"<div><p>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 (<em>Salmo marmoratus</em>) and brown trout (<em>Salmo trutta</em>), grayling (<em>Thymallus thymallus</em>), and bullhead (<em>Cottus gobio</em>). 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 fine sediment deposition, with the latter predominantly impacting juveniles and the most bottom dwelling species, i.e., the bullhead. The study confirms the need for improving the management of the hydro-sedimentary regime of regulated rivers to preserve the habitat of fish species, particularly of those characterized by conservation status already endangered.</p></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"39 4","pages":"Pages 514-530"},"PeriodicalIF":3.5000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1001627923000665/pdfft?md5=2947c24cd89524d6a698e3efcb6a9b31&pid=1-s2.0-S1001627923000665-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Hydro-morphological alteration and related effects on fish habitat induced by sediment management in a regulated Alpine river\",\"authors\":\"\",\"doi\":\"10.1016/j.ijsrc.2023.10.001\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>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 (<em>Salmo marmoratus</em>) and brown trout (<em>Salmo trutta</em>), grayling (<em>Thymallus thymallus</em>), and bullhead (<em>Cottus gobio</em>). 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 fine sediment deposition, with the latter predominantly impacting juveniles and the most bottom dwelling species, i.e., the bullhead. The study confirms the need for improving the management of the hydro-sedimentary regime of regulated rivers to preserve the habitat of fish species, particularly of those characterized by conservation status already endangered.</p></div>\",\"PeriodicalId\":50290,\"journal\":{\"name\":\"International Journal of Sediment Research\",\"volume\":\"39 4\",\"pages\":\"Pages 514-530\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S1001627923000665/pdfft?md5=2947c24cd89524d6a698e3efcb6a9b31&pid=1-s2.0-S1001627923000665-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Sediment Research\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1001627923000665\",\"RegionNum\":2,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Sediment Research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1001627923000665","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Hydro-morphological alteration and related effects on fish habitat induced by sediment management in a regulated Alpine river
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 fine sediment deposition, with the latter predominantly impacting juveniles and the most bottom dwelling species, i.e., the bullhead. The study confirms the need for improving the management of the hydro-sedimentary regime of regulated rivers to preserve the habitat of fish species, particularly of those characterized by conservation status already endangered.
期刊介绍:
International Journal of Sediment Research, the Official Journal of The International Research and Training Center on Erosion and Sedimentation and The World Association for Sedimentation and Erosion Research, publishes scientific and technical papers on all aspects of erosion and sedimentation interpreted in its widest sense.
The subject matter is to include not only the mechanics of sediment transport and fluvial processes, but also what is related to geography, geomorphology, soil erosion, watershed management, sedimentology, environmental and ecological impacts of sedimentation, social and economical effects of sedimentation and its assessment, etc. Special attention is paid to engineering problems related to sedimentation and erosion.