Humans transforming the global water system

Vörösmarty, Charles J; Lettenmaier, Dennis P.; Lévêque, Christian; Meybeck, Michel; Pahl‐Wostl, Claudia; Alcamo, Joseph; Cosgrove, William J.; Graßl, Hartmut; Hoff, Holger; Kabat, P.; Lansigan, Felino P.; Lawford, R. G.; Naiman, Robert J.

doi:10.1029/2004eo480001

Cited by 208 publications

(122 citation statements)

References 2 publications

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“…The construction and operation of Ͼ45,000 large (Ͼ15 m high) dams worldwide during the 20th century (7) has severely altered the global flux of water and sediment from continents to oceans through the world's river basins (8,9). From an ecological perspective, the fragmentation of river corridors by dams (10) and the associated modification of fluvial processes and streamflow dynamics pose significant threats to native river biodiversity on a global scale (11)(12)(13)(14).…”

mentioning

confidence: 99%

Homogenization of regional river dynamics by dams and global biodiversity implications

Poff¹,

Olden

Merritt

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

1,277

866

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Global biodiversity in river and riparian ecosystems is generated and maintained by geographic variation in stream processes and fluvial disturbance regimes, which largely reflect regional differences in climate and geology. Extensive construction of dams by humans has greatly dampened the seasonal and interannual streamflow variability of rivers, thereby altering natural dynamics in ecologically important flows on continental to global scales. The cumulative effects of modification to regional-scale environmental templates caused by dams is largely unexplored but of critical conservation importance. Here, we use 186 long-term streamflow records on intermediate-sized rivers across the continental United States to show that dams have homogenized the flow regimes on third-through seventh-order rivers in 16 historically distinctive hydrologic regions over the course of the 20th century. This regional homogenization occurs chiefly through modification of the magnitude and timing of ecologically critical high and low flows. For 317 undammed reference rivers, no evidence for homogenization was found, despite documented changes in regional precipitation over this period. With an estimated average density of one dam every 48 km of third-through seventh-order river channel in the United States, dams arguably have a continental scale effect of homogenizing regionally distinct environmental templates, thereby creating conditions that favor the spread of cosmopolitan, nonindigenous species at the expense of locally adapted native biota. Quantitative analyses such as ours provide the basis for conservation and management actions aimed at restoring and maintaining native biodiversity and ecosystem function and resilience for regionally distinct ecosystems at continental to global scales. disturbance ͉ natural flow regime ͉ ecosystem sustainability ͉ environmental template

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mentioning

confidence: 99%

Homogenization of regional river dynamics by dams and global biodiversity implications

Poff¹,

Olden

Merritt

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

1,277

866

View full text Add to dashboard Cite

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“…They stated that GE will be necessary in order to produce crops at current production levels, let alone the production levels required in 2050 (Fedoroff, et al, 2010). Given the likelihood of significant future temperature increases (Anderson & Bows, 2008;Intergovernmental Panel on Climate Change, 2007), water shortages (Brown, 2008;Gleick, 2003;Vorosmarty, et al, 2004), salinity and degraded soil conditions in many of the world's major growing regions (Lal, 2007;Pimentel & Sparks, 2000), genetic engineering of crops is certainly an appropriate research strategy.…”

Section: Genetic Engineering and Some Potential Planetary Threatsmentioning

confidence: 99%

Genetic Engineering and Moral Responsibility

Small¹

2012

Genetic Engineering - Basics, New Applications and Responsibilities

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“…Predictions for several of the water-management scenarios evaluated in the case study are directly relevant to tradeoffs between human water needs and ecosystem function, which may intensify as demands on water resources increase within the study area [70] and in many other watersheds globally [1,4,22,71]. For example, incorporating a hypothetical secondary water withdrawal site within the Obed River Basin resulted in greater frequency of low-flow conditions and reduced predicted fish species richness for pool dwellers, lithophilic spawners, and specialized insectivores immediately downstream at Location 2.…”

Section: Meeting the Information Needs Of Water-resource Managersmentioning

confidence: 99%

Putting Flow–Ecology Relationships into Practice: A Decision-Support System to Assess Fish Community Response to Water-Management Scenarios

Cartwright

Caldwell

Nebiker

et al. 2017

Water

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This paper presents a conceptual framework to operationalize flow-ecology relationships into decision-support systems of practical use to water-resource managers, who are commonly tasked with balancing multiple competing socioeconomic and environmental priorities. We illustrate this framework with a case study, whereby fish community responses to various water-management scenarios were predicted in a partially regulated river system at a local watershed scale. This case study simulates management scenarios based on interactive effects of dam operation protocols, withdrawals for municipal water supply, effluent discharges from wastewater treatment, and inter-basin water transfers. Modeled streamflow was integrated with flow-ecology relationships relating hydrologic departure from reference conditions to fish species richness, stratified by trophic, reproductive, and habitat characteristics. Adding a hypothetical new water-withdrawal site was predicted to increase the frequency of low-flow conditions with adverse effects for several fish groups. Imposition of new reservoir release requirements was predicted to enhance flow and fish species richness immediately downstream of the reservoir, but these effects were dissipated further downstream. The framework presented here can be used to translate flow-ecology relationships into evidence-based management by developing decision-support systems for conservation of riverine biodiversity while optimizing water availability for human use.

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Humans transforming the global water system

Cited by 208 publications

References 2 publications

Homogenization of regional river dynamics by dams and global biodiversity implications

Homogenization of regional river dynamics by dams and global biodiversity implications

Genetic Engineering and Moral Responsibility

Putting Flow–Ecology Relationships into Practice: A Decision-Support System to Assess Fish Community Response to Water-Management Scenarios

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