1. Definition
Name |
IRRIGATED
AREA |
Brief definition |
Land area under
irrigation as a percentage of total arable land area |
Unit
of measure |
% |
2. Position
within the logical framework DPSIR
Type of Indicator |
Driving Force
|
3. Target and
political pertinence
Objective |
The purpose
is to show the degree of importance of irrigation within the
country's agricultural sector, from the point of view of water
and land resource utilization |
Importance
with respect to desertification |
This indicator
shows to what extent arable land and water resources are already
used in an intensive manner. It can indicate level of conversion
of land to high input agriculture. Availability of irrigation
water is linked to other intensification processes with potentially
negative effects on sustainability, such as monoculture, selection
of high yielding varieties to the detriment of genetic diversity,
runoff and soil erosion, compaction, and salinization that lead
to accelerated desertification process. Sustainability assessment
of changes in the indicator is linked to water availability
and soil suitability for irrigation |
International
Conventions and agreements |
The UNCCD emphasizes
the development of sustainable irrigation programmes for both
crops and livestock as a measure to prepare for and mitigate
the effects of drought. |
Secondary
objectives of the indicator |
Extensive
standing water area is linked to incidence of salinization.
It also relates to conflicts in the use of water resources. |
4. Methodological
description and basic definitions
Definitions
and basic concepts |
Arable land is officially
defined as "land under temporary crops, temporary meadows
for mowing or pasture, land under market and kitchen gardens,
and land temporarily fallow." That definition tends to
equate arable land with cultivated land. The Food and Agricultural
Organization's (FAO) definition of cultivated land is that
under temporary (annual) crops, but some countries (outside
the EU) may include perennial crops in cultivated land. Therefore,
complications may arise from cross-country comparisons.
The way multiple cropping
and intercropping are accounted for is not standardized and
not always clear. Irrigation potential is determined on assumptions
that vary from country to country. It should be based on annual/seasonal
water and land resource availability (depending on topography,
infiltration). As land and water resources do not always coincide,
technological options (i.e. basin transfers, storage) should
be judged by economic and environmental considerations. Except
in a few cases, no consideration is given to the possible
double counting of shared water resources. Mangrove, wetland
and flood plains (resources with high environmental value)
are usually, but not systematically, included in the irrigation
potential. The concept of "water managed areas"
includes "irrigated areas" (i.e. equipped with hydraulic
structures) as well as cultivated wetland and valley bottoms
without irrigation equipment.
|
Benchmarks
Indication of the values/ranges of value |
Trend |
Methods
of measurement |
Irrigated
area (area equipped with hydraulic structures) divided by arable
land. |
Limits of the
indicator |
There are conceptual
and methodological difficulties of interpretation. Some national
data use a narrow definition while other data may be broadly
defined. Some countries report areas with irrigation facilities,
while others use areas provided with water, so the differences
between irrigable areas and irrigated areas (areas where water
is effectively used) is not clear. The indicator value does
not capture the quality or conditions of both land and water
resources. Knowledge of other factors such as crops grown, agro-ecological
zone type, and distribution of farm size would be relevant to
its interpretation. Other aspects of irrigation, including equity,
efficiency, and importance to the overall national agricultural
production are not reflected in the indicator. The indicator
does not provide a measure of lands with irrigation potential.
|
Linkages
with other indicators |
Water
leakage; Irrigation
potential realised; Area affected by salinity and water
logging; Annual withdrawals of water; Groundwater reserves;
Land use evolution. |
5. Evaluation
of data needs and availability
Data required
to calculate the indicator |
Data on irrigated
land and arable land. |
Data sources |
Regional and
National Agencies involved in the managing of water resources
(i.e. Authority of Basin in Italy). Data on Arable land is available
from Agricultural Census |
Availability
of data from national and international sources |
Recent
data are available at the country level in FAO's AQUASTAT (1994/1995)
which is directly based on official national data. Data are
also available from national sources in some countries only.
The data are estimated by countries at various periods and are
then interpolated. Data from 1970s are available as part of
country statistics in WAICENT |
6. Institutions
that have participated in developing the indicator
Main institutions
responsible |
University
of Basilicata |
Other
contributing organizations |
Universities
of Lisbon, Murcia, Athens |
7. Additional
information
Bibliography
|
Eurostat. 1997.
Agriculture Statistical Yearbook 1997. Luxembourg. |
Other references |
The lead agency
is the Food and Agriculture Organization (FAO). The contact
point is the Assistant Director-General, Sustainability Department,
FAO; fax no. (39 6) 5225 3152 |
Contacts
Name and address |
Prof.
Giovanni Quaranta
Dipartimento Tecnico-Economico
per la Gestione del Territorio Agricolo-Forestale
Università della Basilicata
Via Macchia Romana
85100 Potenza
Italia
quaranta@unibas.it |
|