5 results
Search Results
2. Impact of climate change on ice regime in a river regulated for hydropower.
- Author
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Timalsina, Netra P., Alfredsen, Knut T., and Killingtveit, Ånund
- Subjects
ICE on rivers, lakes, etc. ,HYDROELECTRIC power plants ,CLIMATE change ,CROSS-sectional method ,HYDROLOGIC models ,FRAZIL ice ,RESERVOIRS - Abstract
Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2015
- Full Text
- View/download PDF
3. The disappearing cryosphere in the southeastern Alps: Introduction to special issue
- Author
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Mauro Hrvatin, Rok Ciglič, Anne Carrey, Blaž Komac, Matija Zorn, and Berry Lyons
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,0211 other engineering and technologies ,Climate change ,021107 urban & regional planning ,Glacier ,02 engineering and technology ,Snow ,Permafrost ,01 natural sciences ,River ice ,Cave ,General Earth and Planetary Sciences ,Cryosphere ,Physical geography ,0105 earth and related environmental sciences - Abstract
Various ice bodies are an important source of paleoenvironmental data, and their study improves the understanding of present and future environmental conditions. Their changes are an important indicator of climate change. This special issue of Acta geographica Slovenica draws attention to the changing and disappearing cryosphere across the globe, with an emphasis on the southeastern Alps, and the necessity to conduct research in this field before the ice disappears forever. This paper briefly summarizes the current body of knowledge on glaciers, permafrost, cave ice, lake and river ice, and snow in the southeastern Alps, and it presents the contribution of Acta geographica Slovenica to this research and the main highlights of all five papers included in this special issue.
- Published
- 2020
4. Long-term change and geospatial patterns of river ice cover and navigability in Southcentral Alaska detected with remote sensing.
- Author
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Brown, Dana R. N., Arp, Christopher D., Brinkman, Todd J., Cellarius, Barbara A., Engram, Melanie, Miller, Mark E., and Spellman, Katie V.
- Subjects
ICE on rivers, lakes, etc. ,REMOTE sensing ,SYNTHETIC aperture radar ,LAND resource ,LANDSAT satellites - Abstract
People who travel on ice-covered rivers to access traditional lands and resources can be profoundly impacted by effects of climate change on river ice seasonality. We used remote sensing, bolstered by citizen science, to assess trends and geospatial patterns of the ice cover in the Copper River Basin of Southcentral Alaska. Our analysis of Landsat imagery from water years (WYs) 1973 to 2021 suggests a severely diminishing season of river ice travel (delayed or incomplete freezeup, early breakup) due to increasing air temperatures. The weekly probability of an adequate ice cover for river crossings declined by an average of 53 percentage points. Ice extent was closely related to accumulated freezing degree days (AFDD). AFDD
Oct-Apr decreased by 15% since WY 1943, a significant warming trend. We mapped the spatiotemporal variation of ice and open water extent with multispectral and synthetic aperture radar (SAR) imagery (Sentinel-2, Sentinel-1). We identified reaches with more reliable opportunities for winter access and others susceptible to extensive open water, differences related to flow energy and channel form. The results of this study can support local decision making and adaptation in response to rapidly changing river ice conditions, and our approach can be applied elsewhere to document change and improve travel safety. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
5. A Canadian River Ice Database from the National Hydrometric Program Archives
- Author
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Barrie Bonsal, Laurent P. de Rham, Spyros Beltaos, Daniel L. Peters, Terry D. Prowse, and Yonas Dibike
- Subjects
lcsh:GE1-350 ,geography ,geography.geographical_feature_category ,Database ,lcsh:QE1-996.5 ,Climate change ,computer.software_genre ,Annual cycle ,Water level ,lcsh:Geology ,River ice ,Data set ,Data extraction ,Data quality ,Spring (hydrology) ,General Earth and Planetary Sciences ,Environmental science ,computer ,lcsh:Environmental sciences - Abstract
River ice, like open-water conditions, is an integral component of the cold-climate hydrological cycle. The annual succession of river ice formation, growth, decay and clearance can include low flows and ice jams, as well as midwinter and spring break-up events. Reports and associated data of river ice occurrence are often limited to single locations or regional assessments, are season-specific, and use readily available data. Within Canada, the National Hydrometric Program (NHP) operates a network of gauging stations with water level as the primary measured variable to derive discharge. In the late 1990s, the Water Science and Technology Directorate of Environment and Climate Change Canada initiated a long-term effort to compile, archive and extract river-ice-related information from NHP hydrometric records. This data article describes the original research data set produced by this near 20-year effort: the Canadian River Ice Database (CRID). The CRID holds almost 73 000 recorded variables from a subset of 196 NHP stations throughout Canada that were in operation within the period 1894 to 2015. Over 100 000 paper and digital files were reviewed, representing 10 378 station years of active operation. The task of compiling this database involved manual extraction and input of more than 460 000 data entries on water level, discharge, ice thickness, date, time and data quality rating. Guidelines on the data extraction, rating procedure and challenges are provided. At each location, time series of up to 15 variables specific to the occurrence of freeze-up and winter-low events, midwinter break-up, ice thickness, spring break-up, and maximum open-water level were compiled. This database follows up on several earlier efforts to compile information on river ice, which are summarized herein, and expands the scope and detail for use in Canadian river ice research and applications. Following the Government of Canada Open Data initiative, this original river ice data set is available at https://doi.org/10.18164/c21e1852-ba8e-44af-bc13-48eeedfcf2f4 (de Rham et al., 2020).
- Published
- 2020
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