Rainbow water: rainfall, the water cycle, forests and trees
• 9.00 Welcome addresses (Prof. Joachim von Braun, ZEF)Block A New scientific insights // chaired by Grace Villamor (ZEF)9.15 Rainbow water, the missing colour. Meine van Noordwijk (ICRAF)9.35 Precipitation sheds, Patrick Keys9.55 What trees can tell us about climate variability and change. Aster Gebrekirstos 10.05 The new West Africa climate centre and this agenda. Manfred Denich& Paul Vlek
•Block B How does this relate to current climate policies and negotiations // chaired by Bruno Locatelli (CIFOR)10.30 Need for climate policy beyond mitigation and adaptation. Peter Minang10.40 Discussant comments. Bruno Verbist (European Forestry Institute)10.45 Discussion on relevance for new, more regional climate negotiations on land cover and water balance
Block C Priorities for linking this emerging science to policy action in climate policies and negotiations chaired by Henry Neufeldt (ICRAF)11.05-11.40 Brainstorm groups11.40-11.50 Plenary reporting11.50-12.00 Closing remarks
CRP6: Forests, Trees and Agroforestry: livelihoods, landscapes and
governance
Rainbow water, the missing colour Meine van Noordwijk (ICRAF)
• Grey water: added focus on pollution, cleansing and re-use water shortage relates to ‘quality’
Rainbow wa-ter closes the hydrological cycle, adds the concept of terrestrial evapotranspi-ration as ‘recycling’
•Rainbow =Recycled Atmospheric Inputs Now Bene-fitting our Water-supply
• Blue water: traditionally hydrology studies water flow in rivers, its use for irrigation, industrial & domestic uses water shortage & floods
• Green water: realized that water use in ‘upper watersheds’ is increased by forests & trees
The foresters’ view of the world
>>
The holistic forest+tree view of the world
Source: Global tree cover inside and outside forest, according to the Global Land Cover 2000 dataset, the FAO spatial data on farms versus forest, and the analysis by Zomer et al. (2009)
>
Forest and tree cover transitions: a unifying concept across CRP6
Temporal pattern
Spatial pattern
Institutional challenge
X-linkage of actions in landscape
Integrate Segregate
Farm fo-restry,
agrofo-rests
Natural forest
Fields, Forests & Parks
Open field agriculture
Plan
tatio
ns
Fiel
ds,fa
llow
, for
est m
osai
c
forest modification
agroforestation
re
- and
affo
rest
ation
defo
rest
ation
Sharing Sparing
Beyond variation in tree cover, we also need variation in ‘pattern’:
Solar radiation and Green-House Gas effect
Rainfall pattern&intensity
Temperature, humidity, windspeed, incoming radiation, potential eva-potranspiration at the level of plants or animals
Local tree cover: wind-breaks, shade trees
Water supply buffered by soil
Plant growth
Vegetation effects on rainfall triggering
Teleconnections of rainfall with sea sur-face temperature
Macro-
Meso-
Micro -climate
Macro-
climateMicro -
In the control simulation (FOREST), we consider a maximally forested world, while in the second
simulation (GRASS) all forests are replaced by grasslands.
oC
Coarsening of pattern: segregate
Ocean tempe-ratures El Nino, IOD
Rainfall in space & time
Land use: •plant production•pathways of water•timing of riverflow
River flow in space & time
Global climate
Upstream livelihoods
Downstream ,, ,,
Wanulcas
GenRiver, FlowPer
SpatRain, TempRain
GCM’s
RUPES/PRESA
CO2, CH4, N2O emissions
Ocean tempe-ratures El Nino, IOD
Rainfall in space & time
Land use: •plant production•pathways of water•timing of riverflow
River flow in space & time
Global climate
Upstream livelihoods
Downstream ,, ,,
Wanulcas
GenRiver, FlowPer
SpatRain, TempRain
GCM’s
RUPES/PRESA
CO2, CH4, N2O emissions
Cloud formation
Most studies have so far taken the global climate as ‘exogenous’ and
started hydrology with actual patterns of rainfall
• Some recent literature suggests that there is more to it…
Ellison D, Futter MN, Bishop K, 2011.On the forest cover–water yield debate: from demand- to supply-side thinking. Global Change Biology, doi: 10.1111/j.1365-2486.2011.02589.x
…the generally beneficial rela-tionship between forest cover and the intensity of the hydro-logic cycle.
…trees can redu-ce runoff at the small catchment scale.
Two schools of thought in the forest water debate: ‘supply-’ and the ‘demand-side’
Key points Ellison et al.• The ‘short cycle’ rainfall can contribute 1/5 – 2/3’s
of rainfall depending on location• About 1/3 of the ‘short cycle’ originates within the
(large) watershed, the rest is from outside• Increased tree water use contributes to ‘intensity
of hydrological cycle’ and may not have to be counted as ‘loss’ from a downstream perspective
Comments: • The same would hold for wetlands, irrigation agri-
culture, use of ‘sprinklers’ • Global increase in water use for irrigated areas
matches increased supply by ‘deforestation’
Bosilovich MG, Schubert SD (2002) Water vapor tracers as diagnostics of the regional hydro-logic cycle. Journal of Hydrometeorolo-gy, 3, 149–165.
Where does the precipi-table water in rainfall come from?
24-57% ‘short cycle’
origins
Ellison D, Futter MN, Bishop K, 2011.On the forest cover–water yield debate: from demand- to supply-side thinking. Global Change Biology, doi: 10.1111/j.1365-2486.2011.02589.x
37%
% of rainfall derived from ‘short cycle’ terrestrial origins(recalculated from Basilovich et al.)
68%58% 30%
40%41% 46% 22%
42%
1) Mackenzie river basin, 2) Mississippi river basin, 3) Amazon river basin, 4) West Afri-ca, 5) Baltics, 6) Tibet, 7) Siberia, 8) GAME (GEWEX Asian Monsoon Experiment) and 9) Huaihe river
basin.
Approximately a third comes
from ‘local’ sources
Terrestrial source areas (‘short cycle’) combine with oceanic (‘long cycle’) in a complex pattern of
‘teleconnections’Areas with high sea surface temperatures (SST) act as source areas of oceanic water vapour, areas with
high ET rates as terrestrial ones, but their link to rainfall in any area depends on dominant wind
patternsBeyond the ‘El Nino’ (ENSO) effect, the ‘Indian
Ocean Dipole’ (IOD) and Sea Surface Temperatures (SST’s) in many areas are now know to correlate
with rainfall
B: bimodal A: unimodal
C: unimodalStrong ENSO
response
Medium ENSO
response
No ENSO response
Bruijnzeel LA (2004) Hydrological functions of tropical forests: not seeing the soil for the trees? Agriculture, Ecosystems and Environment, 104, 185–22
Zeng, N., Neelin, J.D., Lau, K.M., Tucker, C.J., 1999. Enhancement of interdecadal climate variability in the Sahel by vegetation interaction. Science 286, 1537–1540
Fig. 1. Annual rainfall anomaly (vertical bars) over the West African Sahel (13–20◦N, 15◦W–20◦E) from 1950 to 1998: (A) observations
Zeng, N., Neelin, J.D., Lau, K.M., Tucker, C.J., 1999. Enhancement of interdecadal climate variability in the Sahel by vegetation interaction. Science 286, 1537–1540
Model with atmosphre & ocean interactions
(SST influences accounted for)
Adding land characteristics: (albedo,
soil moisture status)
Adding vegetation characteristics, with recovery time-lags
Bruijnzeel LA (2004) Hydrological functions of tropical forests:not seeing the soil for the trees? Agriculture, Ecosystems andEnvironment, 104, 185–22
Fig. 1. Geography of the regions where the dependence of precipitationP on distance x from the source of moisture was studied.
van der Ent RJ, Savenije HHG, Schaefli B, Steele ‐Dunne SC, 2010. Origin and fate of atmospheric moisture over continents. Water Resources Research 46, W09525,
E/P
Pfrom Et/P
Why India and China should invest in draining the Sudd and letting the water evaporate in Egypt in stead… and why
West Africa should be opposed to it
Deforesting Myanmar
will reduce rainfall in
China
South Africa’s concept of pay-ments for tree plantations that evaporate water at above-average rates, can not be transferred to E. Africa, where such evapotrans-piration is likely to return as rainfall.
Fig. 1. Geography of the regions where the dependence of precipitationP on distance x from the source of moisture was studied.
The transects that Makarieva & Gorshkov (2007) studied did not related to main mois-ture flux vector of van der Ent c.s.
Makarieva & Gorshkov pro-pose a ‘strong’ version of the
biotic effect where forests
generate wind & moisture
transport
Keys PW, van der Ent RJ, Gordon LJ, Hoff H, Nikoli R and Savenije HHG, 2012. Analyzing precipitationsheds to understand the vulnerability of rainfall dependent regions, Biogeosciences, 9, 733–746
Dryland agricultural areas where more than 50% of rainfall is derived from terrestrial recycling
Sahel
VOL + EL = PL ‘long cycle’ ‘short cycle’
Land + Atmosphere as hydro-logically open system
7 domains of hydrological influence of trees and forests:1.Enhanced EL means increased precipitation2.Triggering precipitation3.P partitioning over Q and Eintercept plus ΔS 4.ΔSL partitioning over Evarious and Q5.Q dynamics influenced by river & riparian zone6.Q use for irrigation7.Q use for domestic + in-dustrial use & recycling of waste water
Blue water
Brown water
Light Green water
Dark Green water
Rainfall
River flow
Water use
Recycled flows
Precipitable at-mospheric water
Oceans
Rainfall – Recycling feeWater ES fee (ES1)Water delivery feeWater cleaning fee (ES2)
~40%
~60%
Global climate change * geo-
graphy
Land use
Light green water
Blue water
Rainbow water
Dark green water
Grey/Brown water
ES1: buffering of waterflows rela-tive to incoming rainfall, securing quality of blue water flows
ES2: Cleaning of waster water to achieve quality standards for re-use
Patch-level water balance:P = Q + E + Sw
Regional water balance: Vi+1 – Vi = ΔSv = Qi = Pi – Ei + ΔSw,i
Rainfall
Water vapour in the air mass
Threshold for natural forest
forest edge
Increasing distance from the ocean – land interface
desert margin
At the ocean land-interface and at any distance from the
ocean, incoming water vapour flow (V) equals outgoing river flow Q
At patch level & annual scale:
P = E + Q
Evapo-transpiration
Rainfall
Water vapour in the air mass
Threshold for natural forest
forest edge
Increasing distance from the ocean – land interfaceIncreasing distance from the ocean – land interface
desert margin
At the ocean land-interface and at any distance from the
ocean, incoming water vapour flow (V) equals outgoing river flow Q
At patch level & annual scale:
P = E + Q
Evapo-transpiration
Sw
V
P E
Q
• Current international climate policy is built on the concept of ‘macro-climate’ change through CO2 and other greenhouse gas emissions
• Land use and land use change does contribute to emissions and hence is part of macro-climate change
• But, it also has a direct micro- and meso-climatic effect on temperature, humidity, windspeed – and even on rainfall
• Such mesoclimatic effects of tree cover work within an annual hydrological cycle, without the timelags of atmospheric policies
• They operate at regional rather than global scale and require new types of negotiations
Conclusions:1.The forest-climate discourse is overly carbonized2.Micro- and mesoclimatic influences of forests & trees have too long been ignored by scientists and remain undervalued in the climate policy arena3.Recent findings on rainbow water hydrology point to teleconnections of geopolitical importance
Mesoclimatic impacts of land cover change: research agenda
• Quantifying land cover change, focus on trees• Understanding drivers of tree cover change and ‘what
it takes’ to influence them• Multiplying change in land cover with ‘water recy-cling
activity factors’ in parallel to ‘GHG emission factors’ for GHG accounting
• Linking land cover change feedbacks into global/ regional climate change models (beyond statistical downscaling routines)
• Scenario studies on economy/environment interface• International/regional negotiations on change
pathways
V M A . X . . X .
. X .
X . X
X X X X X X
Geopolitics of climatic teleconnections, payments for ecosystem services and
pri-cing of water: four colours of water• Rainbow water is the source of all green, blue and
brown water flows• A large share of PES is linked to water delivery with
direct link between ‘goods’ and ‘services’• New insights into rainfall generation suggest
substantial (~40%) role for short cycle rain• Teleconnections on short cycle rain from green water
use suggest complex political relations• PES funds derived from blue water use need to
balance brown, green and rainbow water allocations
‘Mesoclimatic’ effects in the UNFCCC• The UNFCCC has been framed around the ‘macro-
climatic’ emission concept; hence mitigation implies reducing emissions and not reducing other anthropogenic change of climatic variables (incl. albedo, hydrological cycle links)
• The UNFCCC concept of ‘adaptation’ is about reducing human & ecosystem vulnerability in the face of anthropogenic climate change: it can (implicitly) include other pathways for anthro-pogenic climate change
http://wallpaperswide.com/rainbow_water-wallpapers.html Rainbow water clo-
ses the hydrological cycle, adds the con-
cept of terrestrial evapotranspiration
as ‘recycling’