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Changing rural-urban relations: A new context for river basin resources management. A synopsis
WATER IS RELATIVELY SCARCER THAN LAND - NEEDS AND DEMANDS GROW
Land productivity is largely dependent on water availability.
Water resources in a basin are basically fixed, and tend to be relatively more scarce than land resources. They are determined by climatic conditions. From what is potentially available, a fraction is made accessible for various uses through technical means and societal arrangements.
The amounts of surface and groundwater being supplied for irrigation (biomass production), industry, urban and household use have increased three times faster than population growth during this century. Still, there are significant development problems in large parts of the world, primarily in Third World countries, due to water shortage, and also because of poor water quality.
Changes in land use may have significant effects on infiltration rates through the soil surface, on the water retention capacity of soils, on sub-surface transmissivity, and thus on the production efficiency of rainfall. This illustrates a man-made water shortage through poor land management.
Further increases in withdrawals of water are becoming progressively more expensive, unsound on environmental and energy grounds, and politically problematic. Competition for whatever amounts of water are made accessible will be more pronounced in coming years, and a new power structure is likely to emerge, as discussed below.
The necessary option is simply "to produce more out of less", that is to produce more food, biomass and other goods with a decreasing amount of water on a per caput basis. Yields from irrigated and from rainfed lands must improve.
Jan Lundqvist, Department of
Water and Environmental Studies, Linköping University,
Sweden |
MISMATCHES IN THE COORDINATION OF LAND AND WATER MANAGEMENT
Some 75 % of all water withdrawn is for irrigation, although rainfed agriculture accounts for about 80% of the world's cropped area. Overall system efficiency in large projects in Asia is estimated at about 30%; conveyance efficiency about 65%, distribution efficiency some 75% and field application efficiency about 60%.
The cost of supplying irrigation water is far in excess of the fees paid by farmers, and the economic and other costs of food production in water-scarce regions may be significantly higher than current world market prices.
Apart from considerations of low efficiency, high cost, environmental damage, etc. the consumptive use of water will preclude alternative uses of the scarce water resources.
RURAL WATER FOR URBAN EXPANSION?
Most of the increase in population in Third World countries will migrate to cities and urban centres. Urban population in Africa, Asia and Latin America will increase by about 2000 million between 1990 and 2020. Between 2000 and 2025, it is estimated that almost the entire population growth will be in urban areas. From being a minority of national populations, the urban population will make up about half, or even more than half of the total, soon after the turn of the century.
A new power structure will then emerge, where rural development, including irrigation which used to have a high priority in overall national development thinking will be scrutinized. Urban culture will bring about changes in preferences for food items, and so affect crop selections and land and water use.
Water supply in urban areas is generally inadequate. Sources in the vicinity of cities are heavily exploited and polluted.
A main option for augmenting supplies in cities is to draw water from rural areas and to aquire water which was previously alloted exclusively to rural development. A large number of schemes are currently being implemented in many countries, where water is being re-allocated from intended rural use to urban uses.
RESOURCE MANAGEMENT IN A BASIN CONTEXT
Three main tasks can be identified:
• Minimize unproductive water losses, such as evaporation; improve overall efficiency through appropriate land/water/nutrient/vegetation interaction.
• Optimize productivity per unit of water, in a basin context, with actions such as the revision of cropping patterns.
• Review and revise allocation criteria for water. Take political decisions about the appropriate degree of food self-sufficiency, and which needs and demands should be given priority over which others.
CORRECT CURRENT PERCEPTIONS AND TRANSLATE THEM INTO REALISTIC POLICY
A "command and control" principle does not work. Projects must be based on the principles of social acceptability and capability, which FAO and others have been stressing.
Perceptional and, indeed, ethical aspects vis-a-vis land and water and their integrated management are significant and will dictate the relative success of projects and of the technical approaches used.
It is time to depart from the notion of water as something that is free to obtain and to pollute. Water must be perceived as a finite, vulnerable and non-substitutable resource, for which there is growing demand and need. Water is comparatively more scarce than land, but it is treated as being more abundant. In areas where water is the scarcer resource, it must be seen as an "economic good" and its most worthwhile use must be the goal. This is the most realistic policy option.