Direct role of plants, water,land in local
climate.
Towards sustainable use of ecosystems and
agriculture
Canberra, CSIRO, 22.March 2010
Jan Pokorný
ENKI, Třeboň, Czech Republic
Czech Agriculture University
Czech Republic
Fundamental role played by water
and vegetation in maintaining
local climate
.
Human modification of a landscape by
deforestation,industrial agriculture and
urbanisation destroys the capacity of an
ecosystem to dissipate
– digest and distribute solar energy
Content
Solar energy from Sun to Earth´s surface
Evaporation and condensation
Examples of energy fluxes in ecosystems
(temperature distribution in lanscape meteostations, remote
sensing)
Greenhouse effect quantification
Case study – Mau Forest
Short and long water cycles
Criteria efficiency and sustainability
Solar constant
Solar energy warms the Earth to an average
temperature of around 15°C or 288 K. For a mean
distance between the Sun and the Earth, the
intensity of solar radiation incident upon a
surface perpendicular to the Sun’s rays measured
above the atmosphere is approximately
1367 W m–2.
This quantity is called the solar constant.
Long term changes of solar constant
(1371 W.m-2 ) are several W m-2 (0.1%)
The actual direct solar irradiance at the top
of the Earth’s atmosphere
fluctuates from 1412 W m–2 in early January
to 1321 W m−2 in early July
due to eliptic trajectory of Earth around Sun. The
amount of solar energy changes over the year by
about ±3.2% (45 W m–2)
Annual income of solar radiation
Czech R. ( temp. zone) 4.14 GJ m−2 (1150 kWh m−2)
Helsinki (Finland) 3.49 GJ m−2
(970 kWh m−2)
Giza (Egypt) 7.45 GJ m−2
(2070 kWh m−2).
The maximum irradiance commonly lies between 800 W
m–2 and 1000 W m–2 in the tropics and subtropics and
during the growing season in temperate zones.
NASA SSE (http://eosweb.larc.nasa.gov/sse)
180 000 TW
comes from Sun to Earth
10 TW
energy in economy of
the World (fossil fuels etc.)
Solar constant average: 1367 W.m-2
ATMOSPHERE
Temperate zone:
:
Earth
max. 1000 W.m-2
1000 – 1200 kWh. m-2.year-1
6 – 8 kWh.m-2.day-1
Flux of solar radiation from Sun (6000K)
to Earth (290 K)
• Flux of solar radiation from Sun (6000K) to
Earth (290 K)
• 2nd law of thermodynamic (energy flows
from warmer to cooler)
• Spectral composition. Solar radiation
consits of UV, visible (light) and near IR.
• Earth emits long wave radiation
• Wien´s law: lmax = 2897 / T
• Notice absorption bands of water
Spectral characteristic of radiation
(W.m-2.µm-1)
Solar energy flux through atmosphere
Solar constant
1,4 kWh.m-2
Wave lenght λ (µm)
Stefan – Boltzmann law
R = τ T4
Wien´s law
λmax = 2897 / T
Net radiation
The sum of all incoming radiation minus all
outgoing radiation across a unit area of the
plane is called net radiation (Rn). The IR part
of radiation contributes to radiation balance
Rn=J+P+G+H+L*E
There is a big difference between the
distribution of net radiation in functioning
natural ecosystems of high plant biomass
well supplied with water vs. dry non-living
physical surfaces.
EVAPOTRANSPIRATION COOLS
Infrared Thermometer was used
to measure Temperature of the;
Photos were taken using
Thermo-vision and Digital
camera
Clear sky -3oC
Cloud 14oC
Thermo-vision Camera
Big tree
29oC
Water
23oC
Dry Grass
34oC
Bare soil
37.6oC
Wood
50oC
bare soil 32,5 °C
meadow 19,8 °C
building 45 °C
Ar 1 meadow , Ar 2 bare soil
IR picture made by termovision camera –high temperature of
roofs, low temperature of wetlands (Wet Meadows).
LATENT HEAT of water vaporization – princip of
airconditioning
Water evaporation - condensation
The transition of liquid into a gas phase is an
endothermic reaction, i.e., energy consumption,
and thus local cooling accompanies it. On the
contrary, condensation is an exothermic process
attended by energy release and local warming. An
amount of 2.45 MJ (0.68 kWh) of energy is needed
for the evaporation of 1 kg water at 20°C; the
same amount of energy is released during
condensation of 1 kg water vapour
Stoma = valve
controling uptake of
CO2 and release of
water vapour
About 100 stomata/mm2
Several hunderds mol
of water released to one mol
carbon dioxide fixed
Transpiration
photosynthesis
The amount of water molecules exchanged
by plants is at least two orders of
magnitude higher than the amount of
carbon dioxide fixed to biomass
Water vapour and CO2 in air
the amount of water vapour found in plant
stands and in the atmosphere is many times
higher and it changes dramatically across
time and space. For example, air saturated with
water at 21°C contains:
18 gm–3 of water vapour, i.e., 22,400 ppm.
Air saturated with water at 40°C contains:
50 gm–3 of water vapour, i.e., 62,200 ppm.
Carbon dioxide increased from 280 to 390
ppm (1750 till present)
Examples of quantitative results
• Meteostation, Bowen ratio
• Remote sensing (airship, aircraft, satellite)
Solar energy fluxes in various
ecosystems
- Autumn barley field (area of 22 ha).
- Wet Meadow (area of c. 200 ha) in the Rožmberk fish
pond (450 ha) floodplain,high sedges (Carex gracilis L., Carex
vesicaria L.), Calamagrostis canescens (Weber), Phalaris
arundinacea L. and Urtica dioica L. The area surrounding the
meteorological station is not managed; •
- Concrete surface (area of 400 m2) within the area of the
Wastewater Treatment Plant of the city of Třeboň.
- Open water surface of the Ruda fish pond (72 ha, depth
c. 2 m).
- Meadow
Meteorological station in the Wet meadows
Meteorological station at the concrete surface
Shortwave radiation
Sensor (Rs)
Air Temperature
&
Relative Humidity
Solar energy panel
Computer
Long wave radiation
Sensor (RL)
Data logger
Soil Temperature
Incoming solar radiation
Difference in solar radiation on a clear and
overcast day
The amounts of incoming radiation on a clear
day:
(e.g., 8 kW m−2 and maximum flux
1000 W m–2)
can be an order of magnitude higher than the
amount of incoming radiation on an overcast
day: (e.g., 0.78 kWh m–2, maximum flux
100 W m–2).
Reflected solar radiation
Sensible and latent heat fluxes
Daily solar energy fluxes on a sunny day
(22.06.08)
Wet meadows
Concrete surface
800
800
Rn
G
LE
H
600
[kW h m-2]
kWh m-2
600
400
200
Rn
G
LE
H
400
200
0
0
-200
23:00:00
07:00:00
15:00:00
On Wet meadows most of
solar energy is converted
into latent heat of vaporisation
Evapotranspiration (LE)
23:00:00
23:00:00
07:00:00
15:00:00
23:00:00
On concrete surface most of
solar radiation is converted into
sensible heat (H)
• Several hunderds W/m2 of sensible heat
are released on a dry surface during a
sunny day.
• Vegetation transferes most of the solar
energy into latent heat
(evapotranspiration)
Remote sensing technologies used for method verification
Thermographic screening comprises data from observations at three different
altitudes. For near-ground altitudes of up to 1 000 m, an airship equipped with
GPS is currently being developed and has been successfully tested; broad-scale
monitoring from an altitude of 300 - 5000 m is carried out by aircraft with
photogrammetric equipment. Both aerial reconnaissance devices are equipped
with FLIR thermographic cameras operating within a spectral range of 7.5 – 15
µm. Satellite photography in the same spectral region can be used for data
interpretation in larger scales.
Airship
A helium-filled airship, which is 8 m long, has 2.5 m in is equipped with an inertial
measurement unit for direct measurements of the heeling angle and acceleration in all
directions in relation to a coordinate system of the gondola, an accurate altimeter, short-wave
radio stations with a range of at least 10 km and a GPS navigation device. Its operating
speed with accumulators and electric engines is 5 m/s; the operating height is up to 1000 m
and the maximum duration is 30 minutes. A gravity suspension located on the gondola is
balanced so as to be constantly at a right angle to the Earth’s surface. Attached to it are
camera operated with a common trigger. The frequency of photography is derived from the
forward speed of the airship.
Aircraft
A methodology of aerial thermographic photography for large areas was developed in
cooperation with ArgusGeo s.r.o. A complement to thermographic photography from
airships, this method provides a full and comprehensive picture of the site under
observation and helps identify sites for closer observation. Pixel sizes were set between
0.3 and 3 m. The aircraft is equipped with a gyrostabilization frame GSM 3000, which
maintains the camera in a direction that remains at a right angle to the Earth’s surface
even during turbulent flights. This is a necessary for create a photomap.
Two flights were carried out under stable climate conditions, on a bright cloudless day on 29
July 2008. The first flight took place at dawn, when the surface was coldest. The second flight
was carried out in the afternoon when the surface temperature reach its maximum value.
Vegetation and temperature –satellite data
Landsat TM scene subset acquired on 10.8. 2004
Dresden
Germany
RGB 321
synthesis =
visible part of
electromagnetic
spectrum
= “photograph”
from the space
Ústí n/L
Mountains
Forest area
Towns and open cast mines
Land cover classification
Chemnitz
Not clasified
Bare surface
Non-forest vegetation
Forest
Water (shadows)
Ústí nad Labem
clouds
[ C]
temperature
information
measured by
satellite for
120x120m area
– no
interpolation
Radiation temperature of land cover – relative scale
Lowest temperature
Low temperature
Middle temperature
High temperature
Highest temperature
Bare grounds
Non-forest vegetation
Forest
Land cover temperature categories
1800000
1600000
1400000
Lowest temperature
1200000
Low teperature
1000000
Middle temperature
800000
High temperature
600000
Highest temperature
400000
200000
0
Bare grounds
Non-forest
vegetation
Forest
On sunny day comes on 20 km2 c. 20000 MW of
solar energy
Sensible heat flux from 20 km2 of drained land
is equal to the
~
POWER all PP in CR
(12 000 MW)
6000 K
Radiative
forcing
300 K
EARTH
300 K
Radiative forcing = effect of GHG, IPCC data
Quantification of green house effect
• Radiative forcing: 1 – 3W/m2
from the beginning of industrial
revolution (1750)
Materials of Intergovernmental Panel on Climate Change
(IPCC)
y
What drives thunderstorms, cyclones, winds,
heavy rains?
• Potentials i.e., differences in temperature,
air pressure, negative and positive
charges. (Gradients)
• Do averages explain formation of
potentials?
Anthropogenic CO2 emissions
are not the only form of human
impact on climate
• interaction between
climate change and land
cover management goes
both ways
• sensible heat created due
to human draining of the
land overheating and
heat potentials in
landscape – strong wind,
heavy rains.
Fluxes of energy in ecosystems
• Primary production (photosynthesis): W. m-2
• Evapotranspiration: hunderds W. m-2
• Decomposition of organic matter in soil: tens W.
m-2
• Heating of plant stands: several to tens W. m-2
• Radiative forcing: 0.2 W.m-2 for 10 years
• Solar radiation on atmosphere during one year:
1351 Wm-2 - 1431 W m-2
• Life processes can easily compensate for
radiative forcing
Life procese directly affect distribution of
solar energy on Earth?
• Indirect effect: Production or Accumulation
of green house gases
• Direct effect:
damping of heat potentials
(humans create potentials by drainage
– overheating)
WHAT TO DO ?
WHAT TO DO ?
WHAT TO DO ?
Drained pasture, natural wetlands and spruce forest are
continuously monitored:
precipitation: amount (mm) – day sum
precipitation quality – 1 week (bulk)
outflow:
flow rate, conductivity, temperature (20 min.)
water quality: 4 weeks
Pasture
Wetland
Forest
Average day waterflows - L.s-1
Wetland
Pasture
Forest
Drainage brings about
oxidation/mineralization of soil organic matter
(organic carbon) and other reduced
substances (ammonium, sulfide, organic
matter).
Proton (H+ is released during oxidation which
results in acidification of soil.
In Europe recent matter losses
as high as 900 to 1500 kg/ha/year
of dissolved solid matter, excluding NaCl,
were observed in agricultural catchment;
the loss of base cations such as
calcium reached 263 kg Ca/ha/year
(more than 650 kg/ha of calcium carbonate
would have to be given back every year)
Old
water paradigm
• Global warming is the main
climatic problem
• Vegetation has low albedo
and facilitates greenhouse
effect. Water vapour acts as
greenhouse gas.
New
water paradigm
• Extremes of weather are
the main climatic problem
• Water and vegetation
alleviate unwanted
temperature differences;
cloudiness moderates
intensity of solar radiation
coming on the Earth´s
surface
www.waterparadigm.org
Old
water paradigm
New
water paradigm
- rainwater is an asset that
needs to be retained
(especially in
soil/plants) – convert
blue water into green
water
www.waterparadigm.org
- rainwater is an
inconvenience,
needs to be quickly
removed
Sequestration of carbon dioxide
by vegetation




2000 GT of carbon is contained in soil
610 GT of carbon in vegetation
750 GT of carbon in atmosphere
Annual increment of carbon in atmosphere: 3.5
GT (which is 0.6% of C in vegetation, 0.2% in the
soil)
Desertification
 Earth losses annualy 200 000 km2 of productive
land due to lack of water
 Desertification: 60 000 km2/year
 According to FAO: 30 - 40 % of continents
surface suffer from water defficiency.
(6.45 x 107 km2).
Stop desertification and bring back
water and vegetation:
 Air-conditioning via short water cycle
 More biomass, more food
 Biodiversity increase
 Carbon sequestration
 Recycling of nurients and water
 Employment
 Any negative effect??
On July 22d [1494], he [Columbus] departed for Jamaica….
every afternoon there was a rain squall that lasted for about
an hour.
The admiral attributes this to the great forests of that land; he
knew from experience that formerly this also occurred in the
Canary, Madeira, and Azore Islands, but since the removal of
forests that once covered those islands they do not have so
much mist and rain as before.”
Christopher Columbus’ biography
by his son Ferdinand
Effect of land cover change on
landscape temperature
distribution. A case study of
Mau forest in Kenya
Petra Hesslerová, Jan Pokorný
Mau Forest
• The Mau Forest Complex (4000 km2) is referred as one of the
largest remaining continuous blocks of indigenous forest in
East Africa
• feeds twelve rivers and six large lakes (Nakuru, Naivasha,
Elmentaita, Victoria, Natron, Mara, etc.)
• Mau Forest deforestation during last three decades shows
dramatic change in precipitation, reduction of outflow
resulting in water shortage in Ramsar lakes, towns and rivers.
• Changes of landscape cover and ecosystem functioning which
took in Europe centuries (conversion of virgin forest into
agriculture land) were realized during one generation in West
Kenya. We can learn lot from the Mau Forest development.
• between 2004 and 2006 more than hundred thousand persons
were forcibly evicted from Mau Forest Complex, no
alternative place to live was offered
• A new hydropower plant Sondu-Miriu constructed on the river
of the same name is not able to produce planned 60MW due to
water shortage
• July 2008, Kenyan Prime Minister Odinga declared that during
last 10 years Mau Forest lost 100 000 ha of area due to
agriculture and illegal cutting, the losses were estimated to 300
million USD
• Kenyan Government decided to evict 200 000 people from the
Mau Forest, to fence the Forest in order to prevent illegal
logging and restore hydrology of the catchment.
The extent of the forest in December 2009 can well detect the synthesis of the spectral channels of Landsat ETM +. The
image is displayed in a false colour composition, since it contains mainly the near and mid infrared spectrum which are
invisible for the human eye. Therefore, colours may not match the reality.
Colour image interpretation is as follows: 1 - dense, humid forest, 2 - Forest area converted to farmland with the
remnants of forest, or plantations; 3 - dry non-forest vegetation, 4a, b – bare surfaces; 5 – lakes (water)
What are the consequences?
Figures show the extent of the Mau forest in the years 1986 (a), 2000 (b) and 2009 (c). The central part
(Eastern Mau) and the eastern part of Maasai Mau are the areas, most affected by deforestation.
Land surface temperature distribution in the years 1986 (a), 2000 (b) and 2009 (c). The
comparison with the figures above, confirms the forest belong to the coldest areas within the
landscape. The temperature differences may reach even 30°C at very short distances.
Total area changes (1986-2000) of dense and humid forests
within Mau forest region
Subset size 124 x 125 km
Dates of acquisition 28.1.1986 and 27.1.2000
Total area changes (1986-2009) of dense and humid forests within
Mau forest region
1986: 520 000 ha
2009: 340 000 ha
Clear cuts:
180 000 ha
The changes of temperature between the years 1986 and 2009,
gained as image difference of the standardized temperature. It is
evident; the extreme rise of temperature is bounded with the
areas of deforestation. Its consequences are also evident in the
Rift Valley region, between the great Lakes Nakuru and Naivasha.
Some areas having been converted into fast-growing plantation
forest show the opposite trend.
There are different greens in the landscape…
Figure (on left) is the RGB colour synthesis of Landsat ETM + channels 4-5-3 displaying different land cover types in
the Kericho region (west edge of the image) in the year 2000. The scene size is 19 x 12 km. Bright and
homogeneous red colour, caused by very high chlorophyll content is typical of the tea plantations; dark and light
brown indicates rain forest; the patch of green display a farmland.
Figure (on right) shows temperature differences between the three different vegetation types in the same region.
Despite having the highest amount of chlorophyll (being the greenest), the temperature of tea plantations ranges
between 30 – 35 °C, that is more than in case of forest. The highest temperature is characteristic for the crops (35
– 45°C), depending on the crop cover, type, wetness, and other factors. This fact shows that the surface
temperature depends on the type of land cover and confirms forests as the coldest landscape segments.
The cooling process of transpiration is often
considered a side effect
rather than a mechanism to control leaf
temperature. Transpiration
is also perceived as a rather negative process.
Plant physiology and hydrology may
use negative terms such as ‘transpiration loss’ and
‘evapotranspiration losses’.
Makarieva Gorskov Biotic pump
How to close water cycle
and not to loose water???
Crop (corn)
Higher temperature on soil surface
results in upward flux of air
Forest
Lower temperature in shrubs
prevents rise of air.
Due to temperature inversin air
does not move up.
Forest
Surface of crowns of trees is warmer
than shrubs at ground.
Temperature of surface of forest canopy
28.3 C
Temperature of shrubs
21.5 C
Functioning of forest
in water cycle
on global scale
(Makarieva, Gorshkov,
biotic pump)
CORN
Higher temperature at soil surface than at top of the stand
Dry light surface of road and granit
has lower albedo (reflectance, whiteness)
than
trees and grass
despite
temperature of „darker“ vegetation is lower
It is vaporisation of water
(evapotranspiration) which cools
vegetation
DESTRUCTION AND RENEWAL
OF SMALL WATER CYCLE
There is a hope of recovery
by returning the lost water back to the land.
Natural Sequence Farming is based on recovery of vegetation
through rain water retention
Overgrazing, fire wood,
Forests cover only 2% of Ethiopia, Kenya
It is consequence of bad landscape management not effect of increase of
green house gases. It is overgrazing which results in overheating
(sensible heat release instead of latent heat of vaporization)
WHAT TO DO ?
WATER & PLANTS
The perfect airconditioning of the Earth
Learn from ecosystems - RECYCLING
Criteria of landscape functioning
• By the principle of self-organisation, the least ageing and
most sustainable system has the best cycling capabilities
and least irreversible material flow. It is relatively free of
landscape entropy.
•
•
•
•
Low matter losses
High gross production
Low temperature differences (dissipation)
(Ripl W. 1995 ETR, 2003, 2010 IJW)
References
• Pokorný, J., Brom, J., Čermák, Hesslerová, P., J., Huryna, H., Nadezhdina,
N., Rejšková, A. 2010 Solar energy dissipation and temperature control by
water and plants, Int. J. Water, Vol 5, No 4, 311 - 336
• Hesslerová, P., Pokorný, J. 2010, Forest clearing, water loss and land
surface heating as development costs. Int. J. Water, Vol 5, No 4, 401 – 418
• Hurynna, H., Pokorný, J., 2010, Comparison of reflected solar radiation, air
temperature and relative humidity in different ecosystems (from fish pond
and wet meadows to concrete surface), In:Vymazal J.(ed.) Water and
Nutriet Management in Natural and Constructed Wetlands, Springer –
Science Business Media pp. 308 – 326
• Kovářová, M., Pokorný, J., 2010 Comparison of long-term monitoring of
temperature and precipitation between wetland and other ecosystems.
Ecohydrology 3, 445 - 456, John Wiley and Sons, Ltd.,DOI:
10.1002/eco.183
• Pokorný, J., Květ, J., Rejšková, A., Brom, J. 2010, Wetlands as energydissipating systems. J Ind Microbiol Biotechnol, 37, 1299 – 1305, Springer
• DOI,10.1007/s10295-010-0873-8
• Kravčík, M., Pokorný, J., Kohutiar, J., Kováč, M., Tóth,
E.: 2008, Water for the Recovery of the Climate. A New
Water Paradigm. Pp 122, People and Water, Association
of Towns and Municipalities of Slovakia, ENKI (Czech
Republic) ISBN: 978-80-89089-71-0,
Waterparadigm.org
•
• Pokorný, J., Rejšková, A. 2008, Water cycle
management, In: Erik Jorgensen and Brian D. Fath
(Editor in Chif), Ecological Engineering. Vol. 5 of
Encyclopedia of Ecology, 5 vols. Pp. (3729 – 3737)
Oxford: Elsevier
In the cool
energy flow thermodynamics and life
E.D.Schneider, D.Sagan
• Thermodynamics of open systems
• Life damps gradients and selforganises
using external source of energy –
sunshine
• Without life (biosphere) temperature
gradient on the Earth would be several
hunderds centigrades
SPECIAL ISSUE: WATER AND THE COMPLEXITIES OF CLIMATE
Guest Editor: Associate Professor Ariel Salleh
International Journal on Water
Editorial:
A sociological reflection on the complexities of climate change
research Ariel Salleh
Water for an integrative climate paradigm
Juraj Kohutiar and Michal Kravčík
Solar energy dissipation and temperature control by water and
plants J. Pokorný, J.Brom, J. Čermák, P. Hesslerová, H. Huryna,
N.Nadehzdina, A. Rejšková
Ecological design for climate mitigation in contemporary urban
living Marco Schmidt
Losing fertile matter to the sea: How landscape entropy affects
climate Wilhelm Ripl
The Biotic Pump: Condensation, atmospheric dynamics and
climate Anastassia M. Makarieva and Victor G. Gorshkov
IJW, special issue
Re-coupling the carbon and water cycles by Natural
Sequence FarmingDuane Norris and Peter Andrews
The principles of Natural Sequence Farming John Williams
Forest clearing, water loss, and land surface heating as development
costs
Petra Hesslerová and Jan Pokorný
Is the United Nations’ REDD scheme conservation colonialism by
default?
James Goodman and Ellen Roberts
The New Water Paradigm, human capabilities and strong
sustainability
Justus Lodemann, Rafael Ziegler and Pavol Varga
NOTHING NEW
Bohemian King, Roman Emperor
CHARLES IV.
„…We order to all towns to build up ponds so that Our Kingdom, Bohemia,
has a lot of fishes and moisture…Water in swamps and bogs accumulated
should evaporate under the condition of sun and warm breeze and so will
affect healthy on plants as a vapour.“
Maiestas Carolina (1351 – 1353)
South Bohema, Třeboň region, Czech Republc
Fishponds – artificial lakes were constructed in 16th century
Solar spectrum incident on the atmosphere
and on the Earth’s surface at sea level.