| Title | Spatial and temporal perspectives on spring break-up flooding in the Slave River Delta, NWT |
| Author | Brock, B.E.; Wolfe, B.B.; Edwards, T.W.D. |
| Author Affil | Brock, B.E., University of Waterloo, Department of Earth and Environmental Sciences, Waterloo, ON, Canada. Other: Wilfrid Laurier University, Canada |
| Source | Hydrological Processes, 22(20), p.4058- 4072, . Publisher: John Wiley & Sons, New York, NY, United States. ISSN: 0885- 6087 |
| Publication Date | Sept. 30, 2008 |
| Notes | In English. 51 refs. GeoRef Acc. No: 287794 |
| Index Terms | air temperature; precipitation (meteorology); flooding; hydrogen; hydrology; ice breakup; isotopes; lacustrine deposits; lake deposits; lakes; lake water; meltwater; oxygen; sediments; snow; snowmelt; surface waters; suspended sediments; wetlands; Canada- -Northwest Territories--Great Slave Lake; atmospheric precipitation; Canada; D/H; discharge; floods; fluvial environment; geologic hazards; Great Slave Lake; isotope ratios; lacustrine environment; lake sediments; Northwest Territories; O-18/O-16; rainfall; Slave River delta; stable isotopes; stream sediments; surface water; suspended materials; tracers; Western Canada |
| Abstract | Spatial and temporal patterns of spring break-up flooding in the Slave River Delta (SRD), Northwest Territories, are characterized during three years (2003-2005) using water isotope tracers and total inorganic suspended sediment (TSS) concentrations measured from lakewater samples collected shortly after the spring melt. Strongly contrasting spring melt periods led to a moderate flood in 2003, no flooding in 2004 and widespread flooding in 2005. Flooded lakes have isotopically- depleted delta 18O (delta 2H) signatures, ranging between -19.2 per mil (-145 per mil) and -17.1 per mil (-146 per mil) and most have high TSS concentrations (›10 mg L-1), while non-flooded lakes have more isotopically-enriched delta 18O (delta 2H) signatures, ranging between -18.2 per mil (- 149 per mil) and -10.6 per mil (-118 per mil) and low TSS concentrations (‹10 mg L-1). These results, in conjunction with the isotopic signatures of Slave River water and snowmelt, are used to estimate the proportion of river- or snowmelt-induced dilution in delta lakes during the spring of each study year. Calculations indicate river flooding caused dilution of ~70-100% in delta lakes, while snowmelt dilution in the absence of river flooding ranged from ~0-56%. A positive relationship exists between the spatial extent of spring flooding in the SRD and level and discharge on the Slave River and upstream tributaries, suggesting that upstream flow generation plays a key role in determining the magnitude of spring flooding in the SRD. Parallel variations in the 46- year instrumental Slave River discharge record and flood stratigraphy in the active delta indicate that there is potential for extending the flood history of the SRD, a development that will contribute to a more robust understanding of the drivers of historic, contemporary and future flood frequency in the delta. Abstract Copyright (2008), Wiley Periodicals, Inc. |
| URL | http://hdl.handle.net/10.1002/hyp.7008 |
| Publication Type | journal article |
| Record ID | 63000521 |