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| Titel |
Impacts of impervious cover, water withdrawals, and climate change on river flows in the conterminous US |
| VerfasserIn |
P. V. Caldwell, G. Sun, S. G. McNulty, E. C. Cohen, J. A. Moore Myers |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 8 ; Nr. 16, no. 8 (2012-08-21), S.2839-2857 |
| Datensatznummer |
250013432
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| Publikation (Nr.) |
 copernicus.org/hess-16-2839-2012.pdf |
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| Zusammenfassung |
| Rivers are essential to aquatic ecosystem and societal sustainability, but
are increasingly impacted by water withdrawals, land-use change, and climate
change. The relative and cumulative effects of these stressors on
continental river flows are relatively unknown. In this study, we used an
integrated water balance and flow routing model to evaluate the impacts of
impervious cover and water withdrawal on river flow across the conterminous
US at the 8-digit Hydrologic Unit Code (HUC) watershed scale. We then
estimated the impacts of projected change in withdrawals, impervious cover,
and climate under the B1 "Low" and A2 "High" emission scenarios on river
flows by 2060. Our results suggest that compared to no impervious cover,
2010 levels of impervious cover increased river flows by 9.9% on average
with larger impacts in and downstream of major metropolitan areas. In
contrast, compared to no water withdrawals, 2005 withdrawals decreased river
flows by 1.4% on average with larger impacts in heavily irrigated arid
regions of Western US. By 2060, impacts of climate change were predicted to
overwhelm the potential gain in river flow due to future changes in
impervious cover and add to the potential reduction in river flows from
withdrawals, decreasing mean annual river flows from 2010 levels by 16%
on average. However, increases in impervious cover by 2060 may offset the
impact of climate change during the growing season in some watersheds. Large
water withdrawals will aggravate the predicted impact of climate change on
river flows, particularly in the Western US. Predicted ecohydrological
impacts of land cover, water withdrawal, and climate change will likely
include alteration of the terrestrial water balance, stream channel habitat,
riparian and aquatic community structure in snow-dominated basins, and fish
and mussel extirpations in heavily impacted watersheds. These changes may
also require new infrastructure to support increasing anthropogenic demand
for water, relocation of agricultural production, and/or water conservation
measures. Given that the impacts of land use, withdrawals and climate may be
either additive or offsetting in different magnitudes, integrated and
spatially explicit modeling and management approaches are necessary to
effectively manage water resources for aquatic life and human use in the
face of global change. |
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