The percentage of global population using at least a basic drinking water service rose from 81 to 89% between 2000 and 2015
3 out of 10 (2.1 billion; 29% global population) did not have a safely managed drinking water service in 2015
844 million still lacked even a basic drinking water service
Water-related deaths impact thousands and costs billions
Average annual impact from inadequate drinking water and sanitation services, water-related disasters. Adapted from WWAP (UNESCO World Water Assessment Programme). 2019. The United NationsWorld Water Development Report 2019: Leaving No One Behind. Paris, UNESCO
In 2015, an estimated 2.1 billion people lacked access to safely managed drinking water services and 4.5 billion lacked access to safely managed sanitation services. (WWAP)
Almost half of people drinking water from unprotected sources live in Sub-Saharan Africa, where the burden of collecting water lies mainly on women and girls, many of whom spend more than 30 minutes on each trip to collect water. (WWAP)
Proportion of population using at least basic drinking water services, 2015 Source: WWAP (UNESCO World Water Assessment Programme). 2019. The United NationsWorld Water Development Report 2019: Leaving No One Behind. Paris, UNESCO
Sanitation
Worldwide, only 2.9 billion people (39% of global population) used safely managed sanitation services in 2015. 40% of these people lived in rural areas.
2.1 billion people had access to “basic” sanitation services.
2.3 billion (one out of every three people) lacked even a basic sanitation service—nearly 1 billion people (892 million) still practiced open defecation.
Global and regional sanitation coverage, 2015. Source: The United Nations World Water Development Report 2019: Leaving No One Behind. Paris, UNESCO, 2019.
Total
groundwater volume in the upper 2 km of continental crust is approximately 22.6
million km3 of which 0.1-5.0 million km3 is less than 50
years old1
The
volume of modern groundwater is equivalent to a body of water with a depth of
about 3 meters spread over the continents2
Groundwater
replenished over a human lifetime of 25-100 years is a finite, limited resource
with a spatially heterogeneous distribution dependent on geographic, geologic
and hydrologic conditions3
Accounts for as much as 33%
of total global water withdrawals4
Over 2 billion people rely on groundwater as their primary water
source5
50% or more of the irrigation water used to grow the world’s food is
supplied by groundwater6
Source: 1,2,3–Gleeson, T., Befus, K. M., Jasechko,
S., Luijendijk, E., & Cardenas, M. B. (2015). The
global volume and distribution of modern groundwater. Nature Geoscience, 9(2), 161–167.doi:10.1038/ngeo2590
4,5,6–Famiglietti,
J. S. (2014). The global groundwater crisis. Nature Climate Change, 4(11), 945–948.doi:10.1038/nclimate2425
Groundwater Use by Country, in cubic kilometers per year
Source: Fienen M.N., Arshad M. (2016) The International Scale of the Groundwater Issue. In: Jakeman A.J., Barreteau O., Hunt R.J., Rinaudo JD., Ross A. (eds) Integrated Groundwater Management. Springer, Cham, DOI The International Scale of the Groundwater Issue
37 Largest Aquifer Systems
Source: Map and table): Richey, A. S., B. F. Thomas, M.-H. Lo, J. T. Reager, J. S. Famiglietti, K. Voss, S. Swenson, and M. Rodell (2015), Quantifying renewable groundwater stress with GRACE, Water Resour. Res.,51, 5217–5238, doi:10.1002/2015WR017349
Aquifer Map #
Aquifer Name
1
Nubian
Aquifer System (NAS)
2
Northwestern
Sahara Aquifer System (NWSAS)
3
Murzuk-Djado
Basin
4
Taoudeni-Tanezrouft
Basin
5
Senegalo-Mauritanian
Basin
6
Iullemeden-Irhazer
Aquifer System
7
Lake Chad
Basin
8
Sudd Basin
(Umm Ruwaba Aquifer)
9
Ogaden-Juba
Basin
10
Congo Basin
11
Upper
Kalahari-Cuvelai-Upper Zambezi Basin
12
Lower
Kalahari-Stampriet Basin
13
Karoo Basin
14
Northern
Great Plains Aquifer
15
Cambro-Ordovician
Aquifer System
16
Californian
Central Valley Aquifer System
17
Ogallala Aquifer
(High Plains)
18
Atlantic and
Gulf Coastal Plains Aquifer
19
Amazon Basin
20
Maranhao
Basin
21
Guarani
Aquifer System
22
Arabian
Aquifer System
23
Indus Basin
24
Ganges-Brahmaputra
Basin
25
West Siberian
Basin
26
Tunguss Basin
27
Angara-Lena
Basin
28
Yakut Basin
29
North China
Aquifer System
30
Song-Liao
Basin
31
Tarim Basin
32
Paris Basin
33
Russian
Platform Basins
34
North
Caucasus Basin
35
Pechora Basin
36
Great
Artesian Basin
37
Canning Basin
Global Aquifer Depletion Hotspots in Arid and Semi-arid Zones
Aquifer
Country
Northwest Sahara #2
Algeria, Libya, Tunisia
California Central Valley #16
USA
High Plains (Ogallala) #17
USA
Guarani #21
Argentina, Brazil, Paraguay, Uruguay
Northern Middle East
Iran, Iraq, Syria, Turkey
Arabian #22
Iraq, Jordan,Oman,Qatar,Saudi Arabia, UAE, Yemen
Northwestern India #23
India, Pakistan
North China Plain #29
China
Canning Basin #37
Australia
Adapted from: Famiglietti, J. S. (2014). The global groundwater crisis. Nature Climate Change, 4(11), 945–948.doi:10.1038/nclimate2425
Highlights from Global Aquifer Hotspots: Central Valley, California (#16)
Most productive agricultural area in the United States
40%+ of Central Valley’s water supply comes from gw, primarily to meet agricultural demand
Groundwater use increased from 0.75 to 2.5 km3 per year between 1962-2003
2007-2010 severe drought caused a permanent aquifer system storage loss of ~2%, due to irreversible compaction of the aquifer system
Source: Ojha, et al., Sustained Groundwater Loss in California’s Central Valley Exacerbated by Intense Drought Periods, Water Resources Research, June 2018, 54(5575). Doi: 10.1029/2017WR022250)Most productive agricultural area in the United States
May 7, 2015 – September 10, 2016 Several trouble spots that were identified in 2015 have continued to subside at rates as high as 0.6 meters (2 feet) per year. Significant subsidence was measured in subsidence bowls near the towns of Chowchilla, south of Merced; and Corcoran, north of Bakersfield. These bowls cover hundreds of square kilometers and continued to grow wider and deeper between May 2015 and September 2016. Subsidence also intensified near Tranquility in Fresno County, where the land surface has settled up to 51 centimeters (20 inches) in an area that extends 11 kilometers (7 miles). NASA Earth Observatory map by Joshua Stevens, using modified Copernicus Sentinel SAR data (2016) courtesy of Tom Farr and Cathleen Jones, NASA Jet Propulsion Laboratory. Caption by Alan Buis (Jet Propulsion Laboratory) and Ted Thomas, California Department of Water Resources; edited by Mike Carlowicz.
Declining groundwater storage appears to be part of the Central Valley’s future
Central Valley groundwater storage trends and simulations The GWD Model simulations for both the past and future years. The simulated groundwater storage changes for the years 1980–2014 (Blue line) are compared with observations (red icons). In future years, several precipitation scenarios are examined. Source: Massoud, E., et al., Projecting groundwater storage changes in California’s Central Valley, Scientific Reports 8(1), August 2018. Doi:10.1038/s41598-018-31201-1
One of the largest gw aquifers in the world (8 states; 450,000 km2)
Provides drinking water for 2.3 million people
Extensively used for agricultural production
Storage decline from 1950-2007 accounts for 36% of total gw depletion during 1900-2008
Depletion is highly variable spatially; very high depletion rates in the southern and central HP, large areas of Texas and Kansas. Low/no depletion in the northern HP aquifer (#14)
November 1, 1998-October 331, 2016 The High Plains Aquifer, also known as the Ogallala Aquifer, is under stress. Farmers today have to drill ever deeper wells in order to pump water for irrigation, and one recent study found the aquifer to be under more strain than any other in the United States. About 30 percent of the water once stored beneath Kansas is already gone, and another 40 percent will be gone within 50 years if current trends continue. The map at the left of this page shows irrigation frequency in the basin between 1999 and 2016. Areas watered nearly every year are purple; those watered only rarely are yellow. The extent of the Ogallala Aquifer is shown with gray. The second image highlights the variability in irrigation between center-pivot irrigation fields in an area along the Colorado-Nebraska border. The most widely grown crops in the basin are corn and wheat. NASA Earth Observatory maps by Lauren Dauphin, using data from Deines, Jillian, et al. (2017). Story by Adam Voiland.
1/3 of India’s aquifers are overexploited, semicritical, or critical
70% of India’s agricultural production depends on gw
GW is the primary source (85%) of drinking water for rural areas
GW is typically extracted by tubewells (~15 million)
In Northwestern India (Rajasthan, Punjab, Haryana, including Delhi) gw has been unsustainably depleted between 2000-2008 in an amount equivalent to double the capacity of India’s largest surface-water reservoir (Rodell, et al., 2009)
This region has a population of approximately 114,000,000.
Region supplies nearly half of China’s wheat and one-third of other cereal grains
Population is more than 200,000,000
Rapid groundwater depletion since the 1980’s
Saltwater intrusion into the freshwater aquifer due to groundwater depletion has salinized 44% of the total area between the coastal plain and Laizhou city.
What remains of the large inland lake is a fraction of what it was in the 1950s and 60s. In those years, the government of the former Soviet Union diverted so much water from the Amu Darya and Syr Darya—the regions’ two major rivers—to irrigate farmland, that it pushed the hydrologic system beyond the point of sustainability. During subsequent decades, the fourth largest lake in the world shrank to roughly a tenth of its former size and divided into several smaller bodies of water.
Aswan High Dam, April 12, 2015 NASA Earth Observatory. Astronaut photograph ISS043-E-101953 was acquired on April 12, 2015
EnvironmentalSignificance
Source: Grill, et
al., Mapping the world’s free-flowing rivers, Nature 569(7755):215- 221, doi: 10.1038/s41586-019-1111-9
Destruction/separation of
floodplains from rivers alters ecosystem services such as natural flood
storage, nutrient retention and flood-recession agriculture
Built river infrastructure has
been linked to declines in terrestrial and freshwater species
Sediment capture by dams may
cause alteration of the geomorphic dynamics of rivers and the shrinking of
river deltas worldwide
Inland fisheries provide the
equivalent of all dietary animal protein for 158 million people worldwide
Only 37% of rivers longer than
1,000 kilometers remain free-flowing in their entire length
Only 23% of rivers longer than
1,000 kilometers flow uninterrupted to the ocean
Very long free-flowing rivers are
largely restricted to remote regions of the Arctic and of the Amazon and Congo
basins
In densely populated areas, only
a few very long rivers remain free-flowing, such as the Irawaddy and Saleen
Dams and Reservoirs
the
leading contributors to the loss of river connectivity
There are approximately 2.8
million dams (with reservoir areas >1000 cubic meters) regulating and
creating over 500,000 kilometers of rivers and canals for navigation and
transport and building irrigation and water-diversion schemes
More than 3,700 hydropower dams
(>1MW) are currently planned or under construction worldwide.
2019 Hydropower Status ReportMore than 21.8 Gw of hydroelectric capacity was put into operation in 20182019 Hydropower Status ReportElectricity generation from hydropower projects achieved a record 4,200 terawatt hours (TWh) in 2018, the highest ever contribution from a renewable energy source, as worldwide installed hydropower capacity climbed to 1,292 GW, according to the 2019 Hydropower Status Report China added the most capacity with the installation of 8,540 megawatts, followed by Brazil (3,866 MW), Pakistan (2,487 MW), Turkey (1,085 MW), Angola (668 MW), Tajikistan (605 MW), Ecuador (556 MW), India (535 MW), Norway (419 MW) and Canada (401 MW). Brazil has now overtaken the United States as the second largest producer of hydroelectricity by installed capacity, after 3,055 MW was put into operation last year at the 11,000 MW Belo Monte complex in the country’s northeast.
Small Hydropower Plants (SHP)
Source: Couto, T. B., & Olden, J. D. (2018). Global proliferation of small hydropower plants – science and policy. Frontiers in Ecology and the Environment, 16(2), 91–100.doi:10.1002/fee.1746
Definition: Considerable variability in definition across
countries; refers broadly to facilities that produce less electricity and operate
in smaller rivers as compared to large hydropower plants. Vary greatly in level of flow control,
storage capacity, diversion structures.
70% of countries classify as installations with less than 10 MW capacity
Significance:
There are close to 11 SHPs for every large hydropower plants (LHPs)
= 11% of global hydropower electricity generation
82,891 SHPs are operating or under construction in 150 countries
181,976 new plants may be installed if all potential capacity were
developed
10,569 new projects appear in national plans
China has the world’s largest number of SHPs—47,073; 57% of the
world’s SHPs
Europe has 26,877 SHPs
Future plans for SHPs are concentrated in Asia, the Americas,
Southern and Eastern Europe and East Africa
Environmental Impacts
Similar to LHPs; but SHPs generally occur in
smaller rivers, which is significant given the ecological importance of
headwater streams
Cumulative ecological impacts of SHPs
(multiple installations in the same river basin) appears to be an underappreciated
issue
Freshwater consumption and the global hydrological cycle
“The freshwater cycle is strongly affected by climate change and its boundary is closely linked to the climate boundary, yet human pressure is now the dominant driving force determining the functioning and distribution of global freshwater systems. The consequences of human modification of water bodies include both global-scale river flow changes and shifts in vapour flows arising from land use change. These shifts in the hydrological system can be abrupt and irreversible. Water is becoming increasingly scarce – by 2050 about half a billion people are likely to be subject to water-stress, increasing the pressure to intervene in water systems. A water boundary related to consumptive freshwater use and environmental flow requirements has been proposed to maintain the overall resilience of the Earth system and to avoid the risk of ‘cascading’ local and regional thresholds.” Stockholm Resilience Planetary Boundaries
Status:
Two control variables:
Global–Maximum amount of consumptive blue water use
4000 cubic km/year (4000-6000 km3/yr)
Regional (River Basin)–Blue water withdrawal as % of mean monthly river flow
Source: (Global Hydrological Cycle in the Anthropocene)This commonly reproduced image from the USGS of the averaged depiction of the hydrological cycle does not represent important seasonal and interannual variation in many pools and fluxes. A hydrologic cycle in the Anthropocene should include:
Include anthropogenic influences
Include global teleconnections
Multiple catchments
Endorheic basins
Estimates of green, blue, and grey water use
Estimates of Global Pools and Fluxes of Water
Estimates of pools and fluxes are based on a synthesis of approximately 80 recent and global-scale studies; volumes represent the central point of the most recent or comprehensive individual estimates. Adapted from Abbott, et al., Nature Geoscience 12, 533–540. 2019
Based on the figures in the previous table, human appropriation (~24,000 km3yr-1) redistributes the equivalent of half of global river discharge or double global groundwater recharge
Irrigated agriculture is the largest water consumer, accounting for ~85-90% of water consumption, followed by industrial, and domestic water use
Global water consumption rose 40% between 1980 (~1,200km3) and 2016 (~1,700km3).
Top Six Water Stressed River Basins by Continent 2012-2016 5-year Index
In each continent, the basin is selected as the one having the
largest water stress index among the top 10% basins that have substantial
electricity generation, crops production, human population, livestock and dam
capacity in each continent.
Source: Wu, N., Wang, C., Ausseil, A. G., Alhafedh, Y., Broadhurst, L., Lin, H. J., Axmacher,J., Okubo, S., Turney, C., Onuma, A., Chaturvedi, R. K., Kohli, P., Kumarapuram Apadodharan, S., Abhilash, P. C., Settele, J., Claudet, J., Yumoto, T., Zhang, Y. Chapter 4: Direct and indirect drivers of change in biodiversity and nature’s contributions to people. In IPBES (2018): The IPBES regional assessment report on biodiversity and ecosystem services for Asia and the Paci c. Karki, M., Senaratna Sellamuttu, S., Okayasu, S., Suzuki, W. (eds.). Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, Bonn, Germany, pp. 265-370.
Over 2 billion people live in countries experiencing high water stress. Recent estimates show that 31 countries experience water stress between 25% (which is defined as the minimum threshold of water stress) and 70%. Another 22 countries are above 70% and are therefore under serious water stress.
It has been estimated that about 4 billion people, representing nearly two-thirds of the world population, experience severe water scarcity during at least one month during the year.
Global overview of countries experiencing different levels of water stress (the ratio of total freshwater withdrawn annually by all major sectors, including environmental water requirements, to the total amount of renewable freshwater resources, expressed as a percentage). Source: WWAP (UNESCO World Water Assessment Programme). 2019. The United NationsWorld Water Development Report 2019: Leaving No One Behind. Paris, UNESCO
Trends in Terrestrial Water Storage (TWS) April 2002-March 2016
Adapted from Rodell, et al. 2018; based on Figure 1 and Table 1 Terrestrial Water Storage = Groundwater + soil moisture + surface waters + snow + ice
The Anthropocene Dashboard 