Einarsson, Sigmundur

Jónasson, Kristján

Thordarson, Thor

English

ScholarWorks@UMass Amherst

River basin geology and geological processesin relation to potential hydropowerdevelopments in a volcanic environment.Item Type event;eventAuthors Thordarson, Thor;Jónasson, Kristján;Einarsson, SigmundurDownload date 2024-09-24 09:13:48Link to Item https://hdl.handle.net/20.500.14394/25354River basin geology and geological processes in relation to potential hydropower developments in a volcanic environment.Thor ThordarsonFaculty of Earth Sciences, University of Iceland Kristján Jónasson and Sigmundur Einarsson Iceland Institute of Natural HistoryThe Geological Aspect of the Assessmenti. The geology = the physical attributes of the river system ii. The geological processes = the builder i.e. supply and changeWhy? riverlakeglacierlavacraterChange the attributes =  change in the habitat AttractionOne of the favorite among anglersis advertised as follows:………… one of the country's most amazing rivers. For admirers of magnificent nature, where man experiences humility in presence of all creationIceland Geological Setting Columbia River Basalt Plateau163,700 km2; 174,000 km3Iceland Basalt Plateau260,000 km2; 650,000 km3Thordarson and Larsen, 2007Volcanism and magmatismLava(km3)Tephra(km3)Tephra (km3,DRE)Total (km3,DRE)%Mafic 369 367 149 518 91Intermediate 23 25 11 34 6Silicic 1.2 54 13 14 3Number of eruptions (last 11 ka)Magma output in km3 (last 11 ka)Effusive Explosive Total %Postglacial historic Postglacial historicMafic 457 41 1772 146 2229 91Intermediate 29 11 112 7 141 6Silicic 15 4 48 8 63 3Thordarson and Hoskuldsson, 200830 active systemsGeology of Iceland 101Thordarson and Larsen, 2007Types eruptions and their impactseffusive & explosive eruptioncentral volcanoes fissure swarmstypically effusive eruptions5 kmThordarson and Hoskuldsson, 2008Central volcanoesSnæfellsjökullAskjaEyjafjallajökull MonogeneticSkjaldbreiðEldborgEldfellLakiOf 25 highly ranked salmon rivers: 16 on the oldest rocks (river maturity)6 on the middle aged rocks (MAR)3 at the boundary of active rift and MAR 0 in the active riftGeology of Highly Ranked Salmon RiversHighly ranked locationsfor other freshwaterfish, such as trout, havedifferent distribution.Types of Riversglacialspring-fedrain-fedmatureimmatureRapid Changes2014-15 eruption at HoluhraunEruption duration: 180 days, 31 Aug 2014 til 27 Feb 2015.(Pedersen et al 2017)Area, 85 km2 (= Manhattan) Volume , 1.2 km3ValuesGeology & hydrologybedrockunconsolidated sediments & processessubterranean water (incl. groundwater & geothermal)rivers & lakesSpeciesvascular plantsbirdsfreshwater fishfreshwater invertebratesthermophilic microbesEcosystemsand soilsecosystems/habitatssoilsLandscape& wildernesswildernessLandscapeCultural heritagearchaeological, historical, legends, superstitionsrichness, diversityrarity size, completeness fragmentation disturbanceinter-national responsi-bilityinformation& symbolic valuevisualvalue+Classes subclassesAttributes2. Ranking of energy alternativesfrom worst to bestThe geological diversity thus considers the formations and tectonic features in the bedrock, the sediment cover on top and all geological processes including tectonic, volcanic and erosion processes.  Assess value Assess impact    Scale 1, 4, 8, 13 and 20. Scores are weighted and total scores calculatedThe concept of diversity is fundamental:Geodiversity: the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (landform, physical processes) and soil features, topography and the el ments of the hydrosphere in the abiotic realm of nature.Búland Power PlantBúland Power PlantAssessment PlanScore Supporting Arguments (reasoning and justification)Knowledge Very good More than 100 peer reviewed articles exist on the geology of the area, including the Laki eruption in 1783-4. Was one of the pillars in Lyell´s arguments put forth in the year 1830 for Uniformitarianism.Diversity 13 Bedrock diversity is fairly high as it includes a wide range of volcanic, intrusive and sedimentary rocks.Rarity 20 The Holocene geological history of the area is exceptional. Laki 1783-4 lava flow field is the second largest since Iceland´s settlement, filled two large river gorges, features numerous fresh water springs.Continuity/degreeof modification20 Areas A-D are pristine and areas E-K weakly modified (by man). The geological continuity over the last 3 million years is very good and exposed.Other factors 20 Laki 1783-4 lava is the only one on Earth in the size category >10 km3 that is completely preserved and exposed and from that perspective it is UNIQUE!Bedrock - ValueExample of Value Based AssessmentA view of the Skaftá River and the Laki lava at the planed site.Búland Power PlantLocation of the planned damBúlandsvirkjunThis part of the river drainage will be dry most of the year.Each year the river will deposit debris behind the dam equivalent to 0.7-2.5 m. Average water depth is 5-6 m.Búland Power PlantScores RökstuðningurUncertainty SmallDiversity 13 Reduced the access to good geological outcrops, especially into the Laki lava.Rarity 20 The power plant will impact heavily on the Laki lava, which is unique for our planet. We will have to go to Mars to see something compatible. Continuity/degreeof modification20 The power plant will destroy the continuity of the Laki lava.Other factors 20 The power plant will have significant affect on the geological continuity of area.Bedrock - Impactÿ Geology and geological processes are essential part of any environmental impact assessmentÿ Geology as become a commodity in Icelandic tourism, hence pristine or untouched nature has become a game changer (i.e. gained more weight in these assessment). ConclusionsPower plants are a permanent scarThank youSkúli Skúlason; Ása Lovísa Aradóttir; Birna Lárusdóttir; Gísli Már Gíslason; Sólborg Una Pálsdóttir; Sólveig K. Pétursdóttir; Tómas Grétar Gunnarsson; Thorleifur Eiríksson; Thorvardur Árnasonthanks to the rest of the team, it has been a great ride, guys!:Last but not least:

River basin geology and geological processes in relation to potential hydropower developments in a volcanic environment.

University of Massachusetts AmherstScholarWorks@UMass AmherstInternational Conference on Engineering andEcohydrology for Fish PassageInternational Conference on Engineering andEcohydrology for Fish Passage 2017Jun 20th, 4:30 PM - 4:50 PMRiver basin geology and geological processes inrelation to potential hydropower developments in avolcanic environment.Thor ThordarsonUniversity of IcelandKristján JónassonIceland Institute of Natural HistorySigmundur EinarssonIceland Institute of Natural HistoryFollow this and additional works at: https://scholarworks.umass.edu/fishpassage_conferenceThis Event is brought to you for free and open access by the Fish Passage Community at UMass Amherst at ScholarWorks@UMass Amherst. It hasbeen accepted for inclusion in International Conference on Engineering and Ecohydrology for Fish Passage by an authorized administrator ofScholarWorks@UMass Amherst. For more information, please contact scholarworks@library.umass.edu.Thordarson, Thor; Jónasson, Kristján; and Einarsson, Sigmundur, "River basin geology and geological processes in relation to potentialhydropower developments in a volcanic environment." (2017). International Conference on Engineering and Ecohydrology for FishPassage. 17.https://scholarworks.umass.edu/fishpassage_conference/2017/June20/17River basin geology and geological processes in relation to potential hydropower developments in a volcanic environment.Thor ThordarsonFaculty of Earth Sciences, University of Iceland Kristján Jónasson and Sigmundur Einarsson Iceland Institute of Natural HistoryThe Geological Aspect of the Assessmenti. The geology = the physical attributes of the river system ii. The geological processes = the builder i.e. supply and changeWhy? riverlakeglacierlavacraterChange the attributes =  change in the habitat AttractionOne of the favorite among anglersis advertised as follows:………… one of the country's most amazing rivers. For admirers of magnificent nature, where man experiences humility in presence of all creationIceland Geological Setting Columbia River Basalt Plateau163,700 km2; 174,000 km3Iceland Basalt Plateau260,000 km2; 650,000 km3Thordarson and Larsen, 2007Volcanism and magmatismLava(km3)Tephra(km3)Tephra (km3,DRE)Total (km3,DRE)%Mafic 369 367 149 518 91Intermediate 23 25 11 34 6Silicic 1.2 54 13 14 3Number of eruptions (last 11 ka)Magma output in km3 (last 11 ka)Effusive Explosive Total %Postglacial historic Postglacial historicMafic 457 41 1772 146 2229 91Intermediate 29 11 112 7 141 6Silicic 15 4 48 8 63 3Thordarson and Hoskuldsson, 200830 active systemsGeology of Iceland 101Thordarson and Larsen, 2007Types eruptions and their impactseffusive & explosive eruptioncentral volcanoes fissure swarmstypically effusive eruptions5 kmThordarson and Hoskuldsson, 2008Central volcanoesSnæfellsjökullAskjaEyjafjallajökull MonogeneticSkjaldbreiðEldborgEldfellLakiOf 25 highly ranked salmon rivers: 16 on the oldest rocks (river maturity)6 on the middle aged rocks (MAR)3 at the boundary of active rift and MAR 0 in the active riftGeology of Highly Ranked Salmon RiversHighly ranked locationsfor other freshwaterfish, such as trout, havedifferent distribution.Types of Riversglacialspring-fedrain-fedmatureimmatureRapid Changes2014-15 eruption at HoluhraunEruption duration: 180 days, 31 Aug 2014 til 27 Feb 2015.(Pedersen et al 2017)Area, 85 km2 (= Manhattan) Volume , 1.2 km3ValuesGeology & hydrologybedrockunconsolidated sediments & processessubterranean water (incl. groundwater & geothermal)rivers & lakesSpeciesvascular plantsbirdsfreshwater fishfreshwater invertebratesthermophilic microbesEcosystemsand soilsecosystems/habitatssoilsLandscape& wildernesswildernessLandscapeCultural heritagearchaeological, historical, legends, superstitionsrichness, diversityrarity size, completeness fragmentation disturbanceinter-national responsi-bilityinformation& symbolic valuevisualvalue+Classes subclassesAttributes2. Ranking of energy alternativesfrom worst to bestThe geological diversity thus considers the formations and tectonic features in the bedrock, the sediment cover on top and all geological processes including tectonic, volcanic and erosion processes.  Assess value Assess impact    Scale 1, 4, 8, 13 and 20. Scores are weighted and total scores calculatedThe concept of diversity is fundamental:Geodiversity: the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (landform, physical processes) and soil features, topography and the el ments of the hydrosphere in the abiotic realm of nature.Búland Power PlantBúland Power PlantAssessment PlanScore Supporting Arguments (reasoning and justification)Knowledge Very good More than 100 peer reviewed articles exist on the geology of the area, including the Laki eruption in 1783-4. Was one of the pillars in Lyell´s arguments put forth in the year 1830 for Uniformitarianism.Diversity 13 Bedrock diversity is fairly high as it includes a wide range of volcanic, intrusive and sedimentary rocks.Rarity 20 The Holocene geological history of the area is exceptional. Laki 1783-4 lava flow field is the second largest since Iceland´s settlement, filled two large river gorges, features numerous fresh water springs.Continuity/degreeof modification20 Areas A-D are pristine and areas E-K weakly modified (by man). The geological continuity over the last 3 million years is very good and exposed.Other factors 20 Laki 1783-4 lava is the only one on Earth in the size category >10 km3 that is completely preserved and exposed and from that perspective it is UNIQUE!Bedrock - ValueExample of Value Based AssessmentA view of the Skaftá River and the Laki lava at the planed site.Búland Power PlantLocation of the planned damBúlandsvirkjunThis part of the river drainage will be dry most of the year.Each year the river will deposit debris behind the dam equivalent to 0.7-2.5 m. Average water depth is 5-6 m.Búland Power PlantScores RökstuðningurUncertainty SmallDiversity 13 Reduced the access to good geological outcrops, especially into the Laki lava.Rarity 20 The power plant will impact heavily on the Laki lava, which is unique for our planet. We will have to go to Mars to see something compatible. Continuity/degreeof modification20 The power plant will destroy the continuity of the Laki lava.Other factors 20 The power plant will have significant affect on the geological continuity of area.Bedrock - ImpactØ Geology and geological processes are essential part of any environmental impact assessmentØ Geology as become a commodity in Icelandic tourism, hence pristine or untouched nature has become a game changer (i.e. gained more weight in these assessment). ConclusionsPower plants are a permanent scarThank youSkúli Skúlason; Ása Lovísa Aradóttir; Birna Lárusdóttir; Gísli Már Gíslason; Sólborg Una Pálsdóttir; Sólveig K. Pétursdóttir; Tómas Grétar Gunnarsson; Thorleifur Eiríksson; Thorvardur Árnasonthanks to the rest of the team, it has been a great ride, guys!:Last but not least:

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River basin geology and geological processes in relation to potential hydropower developments in a volcanic environment.

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