Transcript IRRIGATION SYSTEMS PERFORMANCE IN GREECE

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IRRIGATION SYSTEMS PERFORMANCE
IN GREECE
Prof. A. Karamanos
Prof. S. Aggelides
Agricultural University of Athens
Agricultural University of Athens
Hammamet, June
2004
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1. EVOLUTION OF IRRIGATION SYSTEMS
2. IRRIGATION SYSTEMS MANAGEMENTS
3. PLANNING AND OPERATIONAL
PARAMETERS OF IRRIGATION SYSTEMS
A.
B.
C.
D.
TECHNICAL
ECONOMICAL
SOCIAL
ENVIROMENTAL
4. CONCLUSION
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1. EVOLUTION OF IRRIGATION SYSTEMS
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Total area:
13,962,000 ha
Total arable land: 3,900,000 ha
Cultivated area:
3,470,000 ha
Irrigated area:
1,430,000 ha
Annual water potential 70x109 m3
Annual water consumption 5,5x109 m3
Water used in agriculture 4,7x109 m3
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4000000
58.8%
3500000
3000000
2500000
1000000
500000
41.2%
1500000
8.4%
2000000
91.6%
Cultivated area (ha)
Total cultivated area (irrigated and non irrigated) in Greece
from 1929 to 2001
0
1929
1939
1950
1961
1971
1981
1991
Year
Irrigated area
Non irrigated area
2001
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Irrigated areas distribution into flat, hilly and mountainous ones
(138,300 ha)
10%
(277,400 ha)
19%
(1,015,100 ha)
71%
Flat area
Hilly area
Mountainous area
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56%
Year
Public irrigation works
Private irrigation works
2001
1998
1994
1990
1986
1982
1978
26%
44%
74%
1600000
1400000
1200000
1000000
800000
600000
400000
200000
0
1974
Irrigated area (ha)
Total irrigated area in Greece from 1974 to 2001
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Proportions of irrigated crops
24%
8%
3%
(40,000ha)
(346,000ha)
(113,500ha)
arable crops
65%
vegetables
trees
(931,000ha)
vines
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2. IRRIGATION SYSTEMS MANAGEMENT
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3. PLANNING AND OPERATION
PARAMETERS
OF IRRIGATION SYSTEMS
A. TECHNICAL PARAMETERS
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Irrigation networks constructed before 1959
Irrigation networks constructed during 1960-69
Irrigation networks constructed after 1970
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Irrigation methods used in public and private networks
private networks
public networks
10%
37%
7%
44%
49%
53%
Surface irrigation
Sprinkler irrigation
Drip irrigation
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Conveyance of irrigation water in public and private
networks
private networks
public networks
65%
Surface flow
35%
Pipelines
95%
5%
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Sources of irrigation water in public and private
networks
public networks
4%
24%
42%
private networks
3%
13%
2%
25%
5%
Rivers and springs
Natural lakes
Artificial reservoirs
Drilled wells and wells
Drainage ditches
82%
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Water and energy consumptions:
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In private networks
Capital intensity
It dominates the model: pumping-flow of water through
pipelines-application with sprinkler or drop irrigation
High operational cost
Lacking of easy available water resources
The water sources are mostly of reduced quantity and quality
The water losses are 10-20% due to the wrong water
application
Water consumption does not exceed 5,000-6,000m3 /ha
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Water and energy consumptions:
In public networks
• High water and energy consumption
• High water losses (up to 50%)
• Water consumption about 10,000m3/ha up to 17,000m3/ha
• Inefficient maintenance
• Extraordinary damaging events
• Unorthodox methods of water application
• Ageing of of networks
• Many earthen delivery canals
• Wrong way of water charging based on area
• Lack of personnel and efficient control techniques
• Low Irrigation Intensity Factor (LIIF 30-40%)
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The reasons of Low Irrigation Itensity Factor:
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Wrong planning of networks
Abandoned fields
Field holders with other employment than farming
Wrong operational of network
Low quality of water
Low quality of service
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B. ECONOMICAL PARAMETERS
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In Greece the economical stability of the
works in the planning stage is examined for
the followed criteria:
• The present value of the work must be positive
• The ratio of present benefit value for present cost value of
the work must be bigger than unity
• The internal rate of return which is the most important
criterion for the “efficiency” of the work
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The compulsory redistribution of land properties
solved three structural problems of Greek
agriculture
• The small holding
• The multiparcelling
• The concomitant high cost of production
From 1959 up to now 900,000ha has been
redistributed:
• 26% cultivated land
• 63% irrigated land
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The cost of water
In the public reclamation works the operational cost is
distributed on an area-basis of irrigated land. This has the
following disadvantages:
• The estimation of the cost is based more on the operational
expenses and less on the staff salaries
• The pricing of water based on the size of parcel is sufficient
for surface networks but it is problematic in irrigation
networks under pressure. It does not create motives for saving
water and energy
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The cost of water
In the private networks:
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the users seem to pay the total amount of cost of the water
supply
the users do not charged for the environmental effects cost
caused by over-pumping
The users strongly subsidized for buying irrigation
equipment and energy (oil, electricity)
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C. SOCIAL PARAMETERS
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The conversion of an area from arid to irrigated
creates:
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Increasing in local employment at least 20%
Reduction in working hours as a result of automation
Tendency to keep rural population at their home
Creation of parallel activities (agrotourism)
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D. ENVIROMENTAL PARAMETER
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• Positive effects
• Drawing up of Environmental Impact Assessments as a tool negative
impacts
• Creation of artificial wetlands
• Reduction in groundwater pumping giving the opportunity to stop
salinazation
• Negative effects
• Degradation of land resources as a result of wrong operation of
drainage systems
• Pollution of surface and underground waters from the excess use of
fertilizers and pesticides
• The salinization of ground water from the excessive water pumping and
the consequent sea-intrusion to the land
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4. CONCLUSION
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There is a strong tendency towards a sustainable
irrigated agriculture:
• winters runoff are stored,
• distribution and application are reduced,
• farmers incomes are raising and unemployment is failing
down,
• environmental benefits from a rational development of water
works are realized
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