Tracking Fresh Water from Space

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Tracking Fresh Water from Space
WatER is an international satellite mission to
meet the requests of the Presidents OSTP OMB
directive to measure, monitor, and forecast the
U.S. and global supplies of fresh water and to
meet the U.N.s resolution that the goals of the
Decade should be a greater focus on water related
issues at all levels and on the implementation of
water-related programmes and projects WatER
initiated from NASAs Surface Water Working Group
and from a similar European community of
scientists, engineers, and users.
Doug Alsdorf, U.S. WaTER PI Nelly Mognard, EU
WatER PI alsdorf.1_at_osu.edu nelly.mognard_at_cnes.fr
Seed funding from the Terrestrial Hydrology
Program at NASA Jared Entin, Program Manager
www.geology.ohio-state.edu/water
www.geology.ohio-state.edu/swwg
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The ability to measure, monitor, and forecast
the U.S. and global supplies of fresh water is
another high-priority concern. Agencies, through
the NSTC (National Science and Technology
Council), should develop a coordinated,
multi-year plan to improve research to understand
the processes that control water availability and
quality, and to collect and make available the
data needed to ensure an adequate water supply
for the Nation's future.
http//www.whitehouse.gov/omb/memoranda/fy04/m04-2
3.pdf
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The WatER Mission
Alsdorf, D. and D. Lettenmaier, Science,
1485-1488, 2003. Alsdorf, D., D. Lettenmaier, C.
Vörösmarty, the NASA Surface Water Working
Group, EOS Transactions AGU, 269-276, 2003.
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Why do we care about streamflow?

• Rivers are the Earths arteries
• Rivers are a primary source of water for human
  consumption, food production, transportation, and
  many other uses
• Riparian corridors, including wetlands, are
  extraordinarily productive and diverse
  biologically
• Much of the worlds population lives in flood
  plains
• Rivers also pose major hazards to human life and
  well being (due to both floods and droughts)

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A thumbnail sketch of global water issues

• Approximately 25,000 people die each year due to
  floods
• 2.2 to 5 million die annually from preventable
  water-related diseases.
• Drought losses globally have exceeded 300B over
  the last decade
• More than 1.2 billion have inadequate drinking
  water (poor quality, insufficient quantity)
• Twice that many (2.5 billion) lack adequate
  sanitation facilities.
• Approximately 10 of the annual discharge of the
  worlds rivers is used consumptively, and several
  major continental rivers (e.g., Colorado, Nile,
  Yellow) are dry for at least part of the year
• The quality of many of the worlds rivers has
  been seriously degraded by a combination of
  pollution, land cover change, dams, and other
  factors
• Science and technology solutions to water
  problems will come from the acquisition of data
  about river discharge, and the storage of water
  in reservoirs, lakes, and wetlands. Water cycle
  models will be greatly improved, thus permitting
  the prediction of water availability and hazards.

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The Problem
Although at least
4 of the earths surface is covered by wetlands
and floodplains, none of this area is gauged
because diffusive flow prohibits in-channel
gauging practices. Reservoirs, lakes and streams
in non-industrialized regions are also unmeasured.
100 Flooded!
Some Resulting Science Questions
How does this lack of measurements limit our
ability to predict the land surface branch of the
global hydrologic cycle? e.g., In locations
where gauge data is available, GCM precipitation
and subsequent runoff miss streamflow by 100
the question is unanswered for ungauged wetlands,
lakes, and reservoirs throughout the world.
What is the role of wetland, lake, and river
water storage as a regulator of biogeochemical
cycles, such as carbon and nutrients? e.g.,
Rivers outgas as well as transport C. Ignoring
water borne C fluxes, favoring land-atmosphere
only, yields overestimates of terrestrial C
accumulation
The Solution
Instrument technology that provides both spatial
area and elevation of the water surface, i.e.,
the Ka-band interferometric altimeter. This JPL
technology will provide decimeter-scale pixels of
the water surface with centimeter-scale
elevations. Hydraulic measurements of h, dh/dt,
dh/dx, and inundated area will all be collected.
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Societal Issues Addressed by WatER

• Floods and Hazard Prediction
• Water Resource Management
• Health and Water Bourne Diseases

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Flooding Issues

• Flooding imposes clear dangers, but the lack of
  water heights and inundation mapping during the
  passage of the flood wave limit important
  hydraulic modeling that would otherwise predict
  the zones of impact.
• Essentially, can we predict flooding hazards
  which could be used to understand the
  consequences of land use, land cover, and
  climatic changes for a number of
  globally-significant, inhabited floodplains?

Prague
Estimated Costs 1.9 Billion Over 100 dead in
Europe, alone
Black Sea
Kentucky
China
India
These are the global floods from 2002, alone!
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Water Management and Availability
For 2025, Relative to 1985

• What are the implications for global water
  management and availability?
• Ability to globally forecast freshwater
  availability is critical for population
  sustainability.
• Water use changes due to population are more
  significant than climate change impacts.
• Predictions also demonstrate the complications to
  simple runoff predictions that ignore human water
  usage (e.g., irrigation).

Vörösmarty, C.J., P. Green, J. Salisbury, and
R.B. Lammers, Global water resources
Vulnerability from climate change and population
growth, Science, 289, 284-288, 2000.
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Trans-Boundary Water Management

• Many of the earths major rivers cross
  international boundaries, which confuse decision
  processes regarding river management. In many
  such cases, information regarding water storage,
  discharge, and diversions in one country that
  affect the availability of water in others is not
  freely available (e.g., the Nile, Jordan, Indus,
  and Mekong). In fact, hydrological observations
  that have implications for water management often
  are closely guarded, and are only released, if
  ever, many years after any practical utility has
  passed. A surface water mission would bring
  about a wholesale change in the availability of a
  huge volume of data with implications for water
  management, access to which would be
  unconstrained by international boundaries.

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Water Bourne Diseases

• Major health issues are also tied to fresh water.
  Disease vectors such as malaria are a function
  of mosquito habitats, which in turn, are directly
  related to water surface areas. Yet, we do not
  have any archival or contemporary mapping of
  these highly dynamic and sometimes ephemeral
  water bodies.

About 3,000,000 people die each year from Malaria
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From the standpoint of global water issues, what
would be the impact of the proposed WatER mission?

• Freely available data on water storage for water
  bodies larger than 1 km
• Capability to produce river discharge estimates
  for many rivers with width gt 50-100 m
• Major implications for the ability to predict
  floods and droughts globally
• Elimination of competive advantage of upstream
  countries in trans-boundary rivers
• Implications for global markets (especially food)

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Possible role and implications of a global
surface water mission

• Free and open exchange of global hydrologic data
  (which presently does not exist)
• Understanding how reservoirs are operated
  (presently there is no coherent data base for
  reservoir storage)
• Water and human health (2 billion incidences of
  water borne diseases per year globally!)

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WatER and Us

• The impact of water availability on mankind is
  obviously great. Thousands of people perish each
  year because of floods whereas over a billion are
  without adequate drinking water Gleick, 2003.
  Indeed, population growth by 2025 is expected to
  impact water availability much more greatly than
  the impacts of greenhouse warming on water
  systems Vörösmarty et al., 2000. Thus, water
  resource issues will have large effects on many
  of the worlds major decisions in the coming
  decades. However, lacking measurements of
  surface water storage changes and fluxes limits
  predictive capabilities regarding future water
  availabilities.