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Desertification Indicator System for Mediterranean Europe


1. Definition

Name WATER AVAILABILITY
Brief definition

Describes the availability of water for irrigation or consumption per person, per year in a region.

Dam converting the water of a river in a channel to be used for irrigation (photo by C. Kosmas)
Unit of measure
  • Annual withdrawal of ground and surface water (m³/yr/inh)
  • Domestic consumption per capita (m³/yr/inh)
Spatial scale Regional
Temporal scale Annual

2. Position within the logical framework DPSIR

Type of Indicator State

3. Target and political pertinence

Objective Contribution to the measures to combat desertification.
Importance with respect to desertification In a water management balance, water demand and supply in a region are compared to assess the challenges and options in water practices, which are aimed at compensating differences between demand and supply at present and in the future. In this case, water shortages may be addressed through anticipatory planning measures. If water is available in an area for irrigation during the dry period, then desertification risk is reduced.
International Conventions and agreements A variety of transboundary legislation exists, as well as EU directives.
Secondary objectives of the indicator Evaluation of the best available water management practices in combating desertification.

4. Methodological description and basic definitions

Definitions and basic concepts

Effective management of water resources at catchment level warrants some anticipation of how water resources are going to change in the future under the influence of both natural and man made changes. Methods for the quantitative analysis include: (1) methods for the analysis of water supply including water availability and water management options; (2) methods for analyzing the water demand in different sectors; (3) models and tools for forecasting both water demand and availability; (4) methods for both optimizing and simulating water resources systems at river basin level.

Knowledge of the hydrological regime of a region or a watershed is a crucial prerequisite for any hydrological work. The available water has to be assessed with regard to quantity and quality of groundwater resources, surface water and marine or coastal waters.

Groundwater resources are of high importance, especially in arid and semi-arid regions where surface water is limited. They include deep and shallow aquifers that are connected to rivers, streams or seas and non-rechargeable (fossil) resources that have been created by precipitation during the last Ice Age. Increasing needs for groundwater systems have basically two implications: the "mining" of groundwater (in which the abstraction exceeds the rate of replenishment) and the degradation of water quality due to point and non-point pollutants. In coastal areas, overexploitation of aquifers can reverse the natural flow into the sea, so that seawater intrusion occurs.

Benchmarks Indication of the values/ranges of value

For a quantitative analysis it is important to have sound estimates of the recharge of the aquifer over a given time period as well as its interactions with surface waters (recharge and discharge). For an assessment of groundwater resources it is essential to have repeated observations of groundwater levels at a relatively large number of observation wells, since groundwater systems respond to short-term and long-term changes in climate, groundwater withdrawal and (artificial) recharge and land uses. Estimates of groundwater storage require the knowledge of aquifer storage properties and accurate interpolation of groundwater level measurements.

Surface waters encompass both rivers and lakes and can quantitatively be assessed by long term averages of the available water resulting from endogenous precipitation. Temporal variations also have to taken into account.

Methods of measurement Hydrological balance estimates. Simulation models.
Limits of the indicator The concept of a sustainable yield is commonly used to limit the extraction from aquifers. Sustainable yield is defined as the long-term average annual recharge that can be extracted each year without causing unacceptable impacts on the environment or other groundwater users. The sustainable yield of a given aquifer is usually given as a fraction of the long-term annual recharge but it is clear that it can only be applied individually to each aquifer.
Linkages with other indicators Rainfall, Soil depth, Slope gradient, Water quality, Vegetation cover, Population growth rate, agricultural water use.

5. Evaluation of data needs and availability

Data required to calculate the indicator Hydrological balance parameters (rainfall, runoff, infiltration etc)
Data sources Necessary data are usually available and accessible.
Availability of data from national and international sources Data can be obtained from national agencies, various regional institutions involved in collecting and elaborating water related data.

6. Institutions that have participated in developing the indicator

Main institutions responsible Agricultural University of Athens, Greece.
Other contributing organizations Universities of Lisbon, Murcia and Basilicata.

7. Additional information

Bibliography

Mediterranean Commission on Sustainable Development (MCSD), 2000:Indicators for the sustainable development in the Mediterranean region, Plan Blue,URL: www.planbleu.org

OECD (Organization for Economic Co-operation and Development):Environmental indicators, towards sustainable development, OECD, 2001.

Other references

American Society of Civil Engineers (ASCE) and UNESCO/IHP-IV Project M-4.3, 1998: Sustainability Criteria for Water Resource Systems, ASCE

International Union for Conservation of Nature and Natural Resources (IUCN), URL: www.iucn.org

Simonovic, S.P., Burn D.H and Lence, B., 1997: Practical Sustainability Criteria for Decion-Making, Int. J. of Sustainable Development and World Ecology, 4(1997), pp. 231-244

Walmsley, J.J., 2002: Framework for Measuring Sustainable Development in Catchment Systems, Environmental Management, Vol. 29, No.2, pp 195-206

World Bank, 1999: Environmental Performance Indicators, A Second Edition Note, Environmental Economic Series, World Bank Environment Department

World Resources Institute (WRI), 2000: Pilot Analysis of Global Ecosystems (PAGE), URL: www.wri.org/wr2000

Young, M.D., 1992: Sustainable Investment and Resource Use. Man and the Biosphere Series, Volume 9, Parthenon Publishing, Carnforth and UNESCO, Paris.

Contacts Name and address

Dr. Ch. Karavitis

Agricultural University of Athens, Greece

email: lsos2kok@aua.gr