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Articleshttps://doi.org/10.1038/s41561-019-0374-y
Human domination of the global water cycle absent from depictions and perceptionsBenjamin W. Abbott 1*, Kevin Bishop 2, Jay P. Zarnetske 3, Camille Minaudo 4,5, F. S. Chapin III6, Stefan Krause7, David M. Hannah 7, Lafe Conner 8, David Ellison9,10, Sarah E. Godsey11, Stephen Plont 3,12, Jean Marçais13,14, Tamara Kolbe2,15, Amanda Huebner1, Rebecca J. Frei1, Tyler Hampton3,16, Sen Gu14, Madeline Buhman1, Sayedeh Sara Sayedi1, Ovidiu Ursache17, Melissa Chapin6, Kathryn D. Henderson18 and Gilles Pinay19
1Brigham Young University, Department of Plant and Wildlife Sciences, Provo, UT, USA. 2Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Uppsala, Sweden. 3Michigan State University, Department of Earth and Environmental Sciences, East Lansing, MI, USA. 4Aquatic Physics Laboratory APHYS, Swiss Federal Institute of Technology EPFL, Lausanne, Switzerland. 5E.A. 6293 GeHCO, François Rabelais de Tours University, Tours, France. 6University of Alaska Fairbanks, Institute of Arctic Biology, Fairbanks, AK, USA. 7School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK. 8American Preparatory Academy Salem Campus, Salem, UT, USA. 9Swedish University of Agricultural Sciences, Department of Forest Resource Management, Umeå, Sweden. 10Ellison Consulting, Baar, Switzerland. 11Idaho State University, Department of Geosciences, Pocatello, ID, USA. 12Virginia Polytechnic Institute and State University, Department of Biological Sciences, Blacksburg, VA, USA. 13Université de Paris, Institut de physique du globe de Paris, CNRS, F-75005, Paris, France. 14Univ Rennes, CNRS, Géosciences Rennes, Rennes, France. 15TU Bergakademie Freiberg, Department of Hydrogeology, Freiberg, Germany. 16University of Waterloo, Department of Earth and Environmental Sciences, Waterloo, Ontario, Canada. 17UMR SAS, AGROCAMPUS OUEST, INRA, Rennes, France. 18Water Research Foundation, Denver, CO, USA. 19Irstea Lyon, RiverLy, University of Lyon, Villeurbanne, France. *e-mail: [email protected]
SUPPLEMENTARY INFORMATION
In the format provided by the authors and unedited.
NATURE GEOSCIENCE | www.nature.com/naturegeoscience
1
CONTENTS
Supplementary Tables
Table S1. Estimates of global water pools and fluxes (p. 2)
Table S2. Five of the most widespread water cycle diagrams (p. 7)
Table S3. Similarity of diagrams from different scientific disciplines (p. 8)
Supplementary Figures
Fig. S1. Examples of the four most common formats used in diagrams of the water cycle (p. 9)
Fig. S2. Accuracy of the representation of five key variables extracted from diagrams created by
different scientific disciplines or for the public (p. 10)
Fig. S3. The number of pools and fluxes represented in water cycle diagrams (p. 11)
Fig. S4. Percentage of diagrams from different scientific disciplines representing major pools
and fluxes in the water cycle (p. 12)
Fig. S5. Ratios and percentages of ocean and land precipitation and evapotranspiration and
overall precipitation to evapotranspiration depicted in diagrams (p. 13)
2
Table S1. Estimates of global water pools and fluxes *To avoid double
counting, we
defined lateral
ocean circulation as
net movement of
water from the
Indian to the
Pacific basin (the
single largest
interbasin flux)
(32) and vertical
ocean circulation as
creation of deep
water with a neutral
density > 28.11 kg
m-3 following
reference (11).
†Previous estimates
of subsurface
runoff did not
separate
groundwater
recharge (defined
here defined
following citation
(16)), which we
have subtracted
from this value.
Pools Volume (103 km3) Range Sources
Total Water on Earth 1,380,000 1,350,000 – 1,386,000 (1–8)
Oceans, Seas, & Bays (total) 1,340,000 1,320,000 – 1,350,000 (1–9)
Deeper water masses 1,206,000 1,100,000 – 1,300,000 (10–12)
Mixed layer 134,000 90,000 – 170,000 (10–12)
Ice caps, Glaciers, & Perennial Snow 25,800 24,064 – 29,200 (1–8)
Groundwater (total) 22,600 8,060 – 23,400 (1–8, 13, 14)
Non-renewable groundwater (old or saline) 22,000 11,000 – 44,000 (13–16)
Renewable groundwater (young and mostly fresh) 630 300 - 1,200 (13–16)
Ground Ice & Permafrost 207 22 – 300 (1–4, 8)
Lakes (total) 190 125 – 229 (1–8)
Fresh lakes 108 91 – 125 (1, 7, 17)
Saline lakes 94.7 85.4 – 104 (1, 7, 17)
Soil Moisture 54.1 16.5 – 122 (1–8)
Wetlands 14.1 11 – 17 (1, 2, 8)
Atmosphere (total) 12.9 12.7 – 13 (1–8)
Atmosphere over sea 10 8 – 12 (2, 18)
Atmosphere over land 3.0 2.7 – 3.3 (2, 18)
Artificial reservoirs 10.8 7 – 15 (1–3, 18, 19)
Seasonal snowpack annual maximum (February) 2.9 2.6 – 3.5 (20–25)
Rivers 1.9 1.25 – 2.12 (1–8)
Biological Water 0.94 0.6 – 1.12 (1–8)
Fluxes Flux (103 km3 year-1) Range Sources
Interbasin ocean circulation* 5,000 4,500 – 6,500 (10–12, 26–32)
Vertical ocean circulation* 2,100 1,600 – 2,600 (10–12, 28, 29)
Ocean evaporation 420.5 350 – 510 (1–3, 18, 33, 34)
Ocean precipitation 380.5 320 – 460 (1–3, 18, 33, 34)
Land precipitation (total) 110.6 99 – 120 (1–3, 18, 33)
Land rain 98.5 88.1 – 120 (2, 18)
Land snow 12.5 11 – 13 (2, 18)
Land evapotranspiration (total) 68.9 62 – 75 (1–3, 18, 33, 35–45)
Transpiration 39.4 34 – 52 (37–42, 44)
Evaporation (soil, water surface, and interception) 29.5 22 – 34 (37–42)
Atmospheric sea to land transport 46 35 – 50 (2, 18, 33)
River discharge to ocean (total) 46 36 – 56 (33, 34, 46–48)
Subsurface flow† 22 21 – 24 (2, 16, 18)
Surface runoff 14 12 – 15 (2, 3, 18)
Groundwater recharge 13 12 – 25 (13, 16, 49)
Groundwater discharge to ocean 4.5 0.1 – 6.5 (2, 6, 7, 13, 50–52)
Land ice discharge 3.1 1.9 – 4.5 (53–56)
Human appropriation of freshwater (total) 24.4 21 – 25 (45, 57–69)
Green water use (total) 19 15 – 22 (44, 59, 66, 70–75)
Grazing 10 8.2 – 14 (44, 45, 58, 76)
Croplands 7.6 6.4 – 7.8 (58, 71, 76)
Forestry 0.96 0.8 – 1.2 (45, 66, 77)
Blue water use (total) 4.0 3.8 – 6.0 (2, 44, 58, 75, 76, 78)
Agriculture 2.5 0.95 – 3.2 (2, 71, 76)
Industry 0.77 0.63 – 0.89 (2, 76)
Domestic 0.31 0.18 – 0.38 (2, 76)
Gray water use (total) 1.4 1.0 – 2.0 (58, 59, 79–82)
Agriculture 0.74 0.5 – 1.0 (58, 59, 79–82)
Industry 0.36 0.21 – 0.5 (58, 59, 79–82)
Domestic 0.28 0.2 – 0.3 (58, 59, 79–82)
River discharge to endorheic basins 0.8 0.6 – 1.1 (83, 84)
3
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Table S2. Five of the most widespread water cycle diagrams
Creator of Diagram # of appearances
Countries Ranking in web search*
Link
United States Geological Survey
15 Tunisia South Africa
Russia Romania
Mexico India
Germany France China Brazil
Australia U.S.A.
2, 19, 26 2 1 1, 2 2 17 2 1 46 2 2 1
https://water.usgs.gov/edu/watercycle.ht ml
U.S. Global Change Research Program (2003)
7 South Africa Romania
India France
Australia Tunisia U.S.A.
27 16 29 17 26 10 2
http://www.globalchange.gov/browse/multimedia/water-cycle
Max Planck Institute
7
Germany China USA
4, 9, 12, 15, 19 39 54
https://www.mpimet.mpg.de/en/communication/multimedia/figures/water
cycle/
United States Geological Survey
6
U.S.A. South Africa
Romania France
Australia India
10 6 11 27 10 5
https://water.usgs.gov/edu/watercycle.html
British Broadcasting Corporation
5 South Africa Australia
U.S.A.
13, 23 17, 30 11
https://www.bbc.com/bitesize/guides/z4bk7ty/revision/1
*Diagrams with multiple rankings showed up multiple times in the image search.
8
Table S3. Similarity of diagrams from difference scientific disciplines*
Geography Hydrology Land management Meteorology
Natural sciences
Pools Geography Hydrology 0.91
Land Management 0.90 0.91 Meteorology 0.81 0.84 0.92
Natural Sciences 0.89 0.87 0.95 0.91 Oceanography 0.80 0.88 0.87 0.85 0.85
Fluxes Geography Hydrology 0.90
Land Management 0.93 0.80 Meteorology 0.91 0.86 0.88
Natural Sciences 0.85 0.89 0.82 0.76 Oceanography 0.89 0.79 0.78 0.89 0.65
*Pearson product-moment correlation coefficients between the number of pools and fluxes included in
diagrams from different disciplines. Because of limited sample sizes in some individual disciplines,
“Natural Sciences” includes data from ecosystem ecology, biogeochemistry, aquatic ecology, and
geology. Similarly, “Land Management” includes data from agronomy, forestry, and soil science.
9
Fig. S1. Examples of the four most common formats used in diagrams of the water cycle. (a)
Catchment format diagrams are large-scale and three dimensional. (b) Hillslope diagrams are
small scale and two dimensional. (c) Site diagrams integrate aspects of catchment and hillslope
diagrams. (d) Schematic diagrams are the most abstract representations, typically consisting of
boxes and arrows. Panels (a) and (d) are from: https://water.usgs.gov/edu/watercycle.html.
Panels (b) and (c) are from: https://pubs.usgs.gov/gip/gw_ruralhomeowner/.
a)
c) d)
b)
10
Fig. S2. Accuracy of the representation
of five key variables extracted from
diagrams created by different scientific
disciplines or for the public. (a) The
percentage of the diagram occupied by
the ocean, (b) percentage of depicted
precipitation occurring over land, (c)
percentage of depicted
evapotranspiration occurring from
land, (d) ratio of total
evapotranspiration to precipitation, and
e) ratio of terrestrial evapotranspiration
to atmospheric flux from ocean to land
(the evapotranspiration multiplier). The
gray bars show current best estimates
of annual values based on values in
Table S1 and box plots represent
median, quartiles, 1.5 times the
interquartile range (IQR), and points
beyond 1.5 times the IQR.
11
Fig. S3. The number of pools and fluxes
represented in water cycle diagrams
grouped by: (a) producer, (b) research
discipline, (c) diagram format, and (d)
time period and whether numerical
estimates of pools and fluxes were
provided. Box plots represent median,
95% confidence intervals of the median
(notches), quartiles, 1.5 times the
interquartile range (IQR), and points
beyond 1.5 times the IQR. For detailed
description of groupings refer to methods
section. See Figure S4 for sample sizes.
12
Fig. S4. Percentage of diagrams from different scientific disciplines representing major (a) pools
and (b) fluxes in the water cycle. Because of limited sample size for some disciplines, we
grouped agronomy, forestry, and soil science into a land management category, and ecosystem
ecology, biogeochemistry, aquatic ecology, and geology into a natural sciences category. See
figure S5 for sample sizes for each discipline.
13
Fig. S5. Ratios and percentages of ocean and land precipitation and evapotranspiration and
overall precipitation to evapotranspiration depicted in diagrams grouped as in Figure S3. The
gray bars show current best estimates of these values based on Table S1.