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How to reduce the water footprint and improve food security in mountain communities. Presented by Hans Schreier at the "Perth II: Global Change and the World's Mountains" conference in Perth, Scotland in September 2010.
Citation preview
How to reduce the water footprint and
improve food security in mountain
communities
Hans Schreier
Faculty of Land & Food Systems
University of British Columbia, Canada
Changes in Irrigation and Water Supply
Storage Reservoirs 1913-1998
1913 1956 1972 !998
Year
Changes in Cropped Area, Alfalfa, and
Fruit, Okanagan Basin 1976-2006
01000020000300004000050000
1976
1981
1986
1991
1996
2001
2006
Are
a i
n h
a
Total Fruit Land in Crops Alfalfa
Changes in Cow numbers in Okanagan
Basin 1976-2006
0
10000
20000
30000
40000
1976
1981
1986
1991
1996
2001
2006
# o
f C
ow
s
Beef Cows Dairy Cows Bulls >1y
Change in Total Hens & Chickens in
Okanagan Basin 1976-2006
0
200000
400000
600000
800000
1000000
1200000
1400000
1976
1981
1986
1991
1996
2001
2006
To
tal #
of
Ch
ick
en
s
Changes in Area/Farm 1981-2006
Okanagan Basin
38
10.4
12.6
49
0
10
20
30
40
50
60
Farm area/Farm Crop area/Farm
Av
era
ge
ha
/Fa
rm
1981 2006
Changes in Fruit & Vegetable Area/Farm
Okanagan Basin 1981-2006
5.3
0.5
2.1
6.4
1.4 1.6
0
2
4
6
8
Grapes/Farm Sweet
Cherries/Farm
Vegetable/Farm
ha
/fa
rm
1981 2006
Irrigated Area under Different Crops (ha)
0100020003000400050006000700080009000
Apple
s
Berr
ies
Cherr
ies
Fruit
Gra
pes
Forage
Veg
etable
s
Golf
Cours
esTurf
Nurs
erie
s
Are
a i
n h
a
Irrigation Water Requirements (Million m3)
010203040506070
Apple
s
Berr
ies
Cherr
ies
Fruit
Gra
pes
Forage
Veg
etable
s
Golf
Cours
esTurf
Nurs
erie
s
Mil
lio
n m
3/y
ear
Irrigation Water Requirements (m3/ha/year)
0
2000
4000
6000
8000
10000
12000
Apples
Berrie
s
Cherrie
sFru
it
Gra
pes
Forage
Veget
ables
Golf
Courses
Turf
Nurser
ies
m3
/ h
a /
year
Irrigation Water requirement for Different
Crops in the Okanagan Basin in 2006
Cherries
6%
Forage
45%
Apples
21%
Berries
0%
Other Fruit
5%
Turf
2%
Nurseries
2%Vegetables
3%
Grapes
8%
Golf
8%
Apples
Berries
Cherries
Other Fruit
Forage
Golf
Grapes
Turf
Nurseries
Vegetables
Irrigation Water Requirements for difference Crops in
the Okanagan Basin in m3/ha/y (2006)
0
2000
4000
6000
8000
10000
12000
Alfalfa
Appl
es
Aprico
ts
Asp
arag
us
Ber
ry
Blu
eber
ry
Cer
eal
Cher
ry
Corn
Cove
r Gra
ss
Fora
ge
GinsingGolf
Gra
pe
Gra
ss
Nec
tarine
Nurs
eryNuts
Pea
ches
Pea
rs
Plu
ms
Ras
pber
ries
Sourc
her
ry
Straw
ber
ry
Swee
tCorn
Tomat
oTurf
Veg
etab
les
Ave
rage
m3/h
a/y
Deviation from the Mean for Irrigation Water
Requirement for all Crops (m3/ha/y)
Alfalfa
Apples
Apricot
Asparagus
Berry
CerealCorn
Forage
Golf
NutsStrawberry
Turf
Vegetables
BlueberryCherry
Ginsing
Grape
Grass
Nectarine
Nursery
Peach
Pear
Plum
RaspberriesSourcherry
SweetCorn
Tomato
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000
5000
1
De
via
tio
n f
rom
me
an
m3
/ha
/ym
Irrigation Factors to Consider
• Climate Change (wet vs. dry years)
• Differences due to Soil Texture
• Different Irrigation Systems
• The Value of Water
Difference between Wet and Dry Years
Difference in m3/ha/y in Irrigation Water
Requirement by Soil Texture between
Wet and Dry Years in m3/ha/y
0
2000
4000
6000
8000
10000
12000
Organic
Heavy
Clay
Clay
Silty
Clay
Silty
Clay L
oam
Silt L
oam
Sandy Loam
Loam
Loamy S
andSand
m3/
ha/
y
1997-Wet 2003-Dry Difference
The Value of Water for Different Crops
Summary
• 70% of all water is allocated for agriculture
• Irrigation: 45% for forage crops, 41% for fruit, 7% for golf courses
• Most Water Demanding: Golf, Apricots, Nectarines 8800-10000m3/ha
• Least Water Demanding Crops: Grapes 4000m3/ha
• Difference in water demand between sandy and clay soils 58%
• Differences between drip & sprinkler irrigation: 41% (4000 vs 9700 m3/ha)
• There is a 40% difference between wet and dry years
• Fruit & vegetables are most sensitive to drought (requiring more water)
• The 45 golf courses use 7% of the irrigation water and are the most inefficient
users of water
• As water becomes scarce selecting water efficient crops will become a viable
conservation strategy.