River Diversion, Irrigation, Salinization, Desertification — an Inevitable Succession

Landuse in arid regions is mainly applied for agriculture; recreational exploitation is not very often found; technical usage of these regions now has started. Three different methods of agriculture are used: animal husbandry, precipitation-fed agriculture and irrigation agriculture.Irrigation systems are some of the most comprehensive undertakings of mankind, not only involving technical and scientific measures, but alsoinflicting social and cultural changes. Economic alterations for the population and the whole society are likely. Management questions are one of the essential points in success or disaster. A historical look at some examples of irrigation culture gives an idea of the difficulties and hazards with which irrigation societies have to cope. Differences in recently installed systems and their performance are evaluated and judged against their proposed aims. Shortcomings are identified in several fields, i.e. in the technical approach, in planned economic possibilities, in social changes and influence on cultural questions, in water management tasks or in the recognition of environmental hazards.Some recommendations are offered to moderate the negative effects. Financing of the irrigation operating system must be guaranteed. Workers and management must be well-trained and motivated. Rotation patterns of crops must be strictly enforced. The market for the goods produced must repay the input. New technologies have to be evaluated and installed. In the case of financial problems, reduction of areas of cultivation as well as of animal relying on the fodder, is essential. Ingenious ideas of new products, i e making use of local weeds or agricultural use of saline lakes, must not be rejected but strongly supported. A larger diversity of crops will help to reduce fertilizer and pestizide impact as well as the dependence on a certain market.