Atle Harby - Academia.edu (original) (raw)
Papers by Atle Harby
Proceedings of the Institution of Civil Engineers, Mar 1, 2009
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This database regroups GHG measurements from freshwater reservoirs. It also includes other reserv... more This database regroups GHG measurements from freshwater reservoirs. It also includes other reservoir and catchment characteristics. This database was used to develop the G-res Tool models. Please see Prairie et al 2017 for more details and for calculations (Prairie, Y. T., Alm, J., Harby, A., Mercier-Blais, S., & Nahas, R. (2017). Technical documentation, UNESCO/IHA research project on the GHG status of freshwater reservoirs. Available at :https://g-res.hydropower.org/guidance-documents/)
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201
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River Research and Applications, 2007
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Journal of Cleaner Production, Dec 1, 2020
Abstract Greenhouse gas (GHG) emissions are receiving worldwide attention and concern over the pa... more Abstract Greenhouse gas (GHG) emissions are receiving worldwide attention and concern over the past decades. However, the net change of GHG emissions due to reservoir creation is not well reported. The objective of the study was to evaluate the net GHG emissions of the Three Gorges Reservoir (TGR), the largest reservoir in volume and installed capacity in China. Here, we provide the first full-scale synthesis of GHG emissions in the TGR. Data from two large sampling campaigns between 2010 and 2017 showed that the post-impoundment GHG emissions of the TGR were 1.36 ± 0.16 × 106 tCO2eq yr−1. A majority of GHGs (30%–70%) are emitted from air-water diffusive pathway in the main stem. Anthropogenic carbon and nutrients loads from the reservoir vicinity did not significantly contribute to the post-impoundment GHG emissions. Reservoir GHG emissions were mainly regulated by annual inflow. Subtracting pre-impoundment GHG emissions from post-impoundment emissions, the net GHG emissions of the TGR in our sampling campaigns were 10.41 ± 1.28 × 105 tCO2eq yr−1. In terms of CO2 equivalents per unit of hydropower production in the same years, they were 11.8 ± 1.8 gCO2eq⋅kWh−1. Mass budget analysis showed that flooding and decomposition of organic matter in flooded land could only explain 19.9% of reservoir net GHG emissions. A large proportion of the net GHG emissions needs further study to be quantitatively identified. In addition, our study elaborated the current limitations and further research needs in evaluation of carbon footprints of reservoir creation.
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12, 2017
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Journal of Cleaner Production, Feb 1, 2021
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River Research and Applications, Jul 12, 2011
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River Research and Applications, 2007
At the 8 km bypass section of Chautagne in the Rhône River, most of the flow is diverted due to h... more At the 8 km bypass section of Chautagne in the Rhône River, most of the flow is diverted due to hydropower production. The environmental flow to the bypass section of the Rhône River was increased from 10 m3 s−1 (winter) and 20 m3 s−1 (summer) to 50 m3 s−1 (winter) and 70 m3 s−1 (summer) in July 2004. A Norwegian mesohabitat method of classifying the river into physical mesoscale morphological (mesohabitat) classes by visual observation was applied at 10 and 70 m3 s−1. The results show that the dominating classes at both flows are deep and low velocity pools, but a higher physical diversity occurs at 70 m3 s−1, quantified by indices from Simpson (1949) and Shannon and Weaver (1962). In total, 6 per cent of the depth measurements and 0.3 per cent of the velocity measurements were outside the expected range at low flow. At high flow, 16.2 per cent of the depth measurements and 19.6 per cent of the velocity measurements were outside the expected range. The change in mesohabitats gives impacts on the composition and abundance of fish and invertebrates. Rheophilic taxa are favoured by the increased flow while more limnophilic species will find less amount of suitable habitat at 70 m3 s−1. Other studies show that population densities of grayling, brown trout, nase and dace have decreased greatly and become endangered since hydropower development, while densities of gudgeon, minnow and stone loach have increased. Fish habitat preferences from Lamouroux et al. (1999a) and Mallet et al. (2000) were used. Most of the endangered species need high velocity mesohabitats and both high and low depths during all life stages. The increase of such mesohabitat proportions at 70 m3 s−1 indicates that their population should recover soon. The method may be a useful tool to compare different flow situations and their impact on the invertebrate and fish population structure even in large rivers. Copyright © 2007 John Wiley & Sons, Ltd.
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Ecosystems, Nov 8, 2017
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Sammendrag: Hydrocen arbeidspakke 4.3 jobber med å utvide miljødesignkonseptet som ble etablert i... more Sammendrag: Hydrocen arbeidspakke 4.3 jobber med å utvide miljødesignkonseptet som ble etablert i forskningssenteret CEDREN. Forskjellige nye aspekter som er viktige for en helhetlig vurdering av positive og negative konsekvenser og tjenester av vannkraft skal legges til, og blant disse er temaet flomdempingstjenester. Denne rapporten går gjennom metodikken vi har utviklet for klassifisering av flomdempingstjenester fra vannkraftmagasin. Metodikken viser potensiell flomdemping på et oversiktsnivå ved å analysere lett tilgjengelige data om magasinstørrelse, årstilsig, typisk magasinfylling over året, tappekapasitet og forholdet mellom reguleringsgrad og demping av flomtopp. Metodikken er ment for system med flere magasin, og en klassifisering vil bli gitt for hvert enkelt magasin sett i sammenheng med resten av systemet. Systemet som helhet blir også klassifisert. Metodikken er laget slik at det er enkelt å se på hvordan endringer i systemet påvirker flomdempingstjenester. Med hjelp fra kraftselskapet Hydro har metodikken blitt anvendt i fem testvassdrag, og resultatene har blitt diskutert med de som har godt kjennskap til vassdragene. Metodikken har blitt forbedret basert på svakheter som ble oppdaget under uttesting og forslag fra diskusjoner. Resultater og kommentarer fra forfatterne er presentert i rapporten, i tillegg til kommentarer om hvor rimelig klassifiseringen virker og hvilke konklusjoner som kan dras. Basert på kunnskap om vassdragene fremstår klassifiseringene som rimelige, og metodikken kan ha nytteverdi for en grov analyse av konsekvenser av endringer i vassdraget
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Proceedings of the Institution of Civil Engineers, Mar 1, 2009
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This database regroups GHG measurements from freshwater reservoirs. It also includes other reserv... more This database regroups GHG measurements from freshwater reservoirs. It also includes other reservoir and catchment characteristics. This database was used to develop the G-res Tool models. Please see Prairie et al 2017 for more details and for calculations (Prairie, Y. T., Alm, J., Harby, A., Mercier-Blais, S., & Nahas, R. (2017). Technical documentation, UNESCO/IHA research project on the GHG status of freshwater reservoirs. Available at :https://g-res.hydropower.org/guidance-documents/)
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201
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River Research and Applications, 2007
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Journal of Cleaner Production, Dec 1, 2020
Abstract Greenhouse gas (GHG) emissions are receiving worldwide attention and concern over the pa... more Abstract Greenhouse gas (GHG) emissions are receiving worldwide attention and concern over the past decades. However, the net change of GHG emissions due to reservoir creation is not well reported. The objective of the study was to evaluate the net GHG emissions of the Three Gorges Reservoir (TGR), the largest reservoir in volume and installed capacity in China. Here, we provide the first full-scale synthesis of GHG emissions in the TGR. Data from two large sampling campaigns between 2010 and 2017 showed that the post-impoundment GHG emissions of the TGR were 1.36 ± 0.16 × 106 tCO2eq yr−1. A majority of GHGs (30%–70%) are emitted from air-water diffusive pathway in the main stem. Anthropogenic carbon and nutrients loads from the reservoir vicinity did not significantly contribute to the post-impoundment GHG emissions. Reservoir GHG emissions were mainly regulated by annual inflow. Subtracting pre-impoundment GHG emissions from post-impoundment emissions, the net GHG emissions of the TGR in our sampling campaigns were 10.41 ± 1.28 × 105 tCO2eq yr−1. In terms of CO2 equivalents per unit of hydropower production in the same years, they were 11.8 ± 1.8 gCO2eq⋅kWh−1. Mass budget analysis showed that flooding and decomposition of organic matter in flooded land could only explain 19.9% of reservoir net GHG emissions. A large proportion of the net GHG emissions needs further study to be quantitatively identified. In addition, our study elaborated the current limitations and further research needs in evaluation of carbon footprints of reservoir creation.
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12, 2017
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Journal of Cleaner Production, Feb 1, 2021
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River Research and Applications, Jul 12, 2011
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River Research and Applications, 2007
At the 8 km bypass section of Chautagne in the Rhône River, most of the flow is diverted due to h... more At the 8 km bypass section of Chautagne in the Rhône River, most of the flow is diverted due to hydropower production. The environmental flow to the bypass section of the Rhône River was increased from 10 m3 s−1 (winter) and 20 m3 s−1 (summer) to 50 m3 s−1 (winter) and 70 m3 s−1 (summer) in July 2004. A Norwegian mesohabitat method of classifying the river into physical mesoscale morphological (mesohabitat) classes by visual observation was applied at 10 and 70 m3 s−1. The results show that the dominating classes at both flows are deep and low velocity pools, but a higher physical diversity occurs at 70 m3 s−1, quantified by indices from Simpson (1949) and Shannon and Weaver (1962). In total, 6 per cent of the depth measurements and 0.3 per cent of the velocity measurements were outside the expected range at low flow. At high flow, 16.2 per cent of the depth measurements and 19.6 per cent of the velocity measurements were outside the expected range. The change in mesohabitats gives impacts on the composition and abundance of fish and invertebrates. Rheophilic taxa are favoured by the increased flow while more limnophilic species will find less amount of suitable habitat at 70 m3 s−1. Other studies show that population densities of grayling, brown trout, nase and dace have decreased greatly and become endangered since hydropower development, while densities of gudgeon, minnow and stone loach have increased. Fish habitat preferences from Lamouroux et al. (1999a) and Mallet et al. (2000) were used. Most of the endangered species need high velocity mesohabitats and both high and low depths during all life stages. The increase of such mesohabitat proportions at 70 m3 s−1 indicates that their population should recover soon. The method may be a useful tool to compare different flow situations and their impact on the invertebrate and fish population structure even in large rivers. Copyright © 2007 John Wiley & Sons, Ltd.
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Ecosystems, Nov 8, 2017
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Sammendrag: Hydrocen arbeidspakke 4.3 jobber med å utvide miljødesignkonseptet som ble etablert i... more Sammendrag: Hydrocen arbeidspakke 4.3 jobber med å utvide miljødesignkonseptet som ble etablert i forskningssenteret CEDREN. Forskjellige nye aspekter som er viktige for en helhetlig vurdering av positive og negative konsekvenser og tjenester av vannkraft skal legges til, og blant disse er temaet flomdempingstjenester. Denne rapporten går gjennom metodikken vi har utviklet for klassifisering av flomdempingstjenester fra vannkraftmagasin. Metodikken viser potensiell flomdemping på et oversiktsnivå ved å analysere lett tilgjengelige data om magasinstørrelse, årstilsig, typisk magasinfylling over året, tappekapasitet og forholdet mellom reguleringsgrad og demping av flomtopp. Metodikken er ment for system med flere magasin, og en klassifisering vil bli gitt for hvert enkelt magasin sett i sammenheng med resten av systemet. Systemet som helhet blir også klassifisert. Metodikken er laget slik at det er enkelt å se på hvordan endringer i systemet påvirker flomdempingstjenester. Med hjelp fra kraftselskapet Hydro har metodikken blitt anvendt i fem testvassdrag, og resultatene har blitt diskutert med de som har godt kjennskap til vassdragene. Metodikken har blitt forbedret basert på svakheter som ble oppdaget under uttesting og forslag fra diskusjoner. Resultater og kommentarer fra forfatterne er presentert i rapporten, i tillegg til kommentarer om hvor rimelig klassifiseringen virker og hvilke konklusjoner som kan dras. Basert på kunnskap om vassdragene fremstår klassifiseringene som rimelige, og metodikken kan ha nytteverdi for en grov analyse av konsekvenser av endringer i vassdraget
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