Ecological versus Economic Objectives: A Public Decision Making Problem in Agricultural Water Management

The planning of a new in·igated area is a complex problem where a multiplicity of very different criteria (economic, ecological, social, etc.) have to be taken into account. A lexicographic goal programming model capable of handling this multiplicity is formulated. The methodology is applied to the planning of the irrigated lands of the village of Tauste in Arag6n (Spain). An important result generated by the model is the conflict between economic criteria and environmental effects such as "saltload," which affects the water quality in the basin. This matter is thoroughly analysed by determining the transformation curve between "salt-load" and the investment outlay in the irrigation systems discussed.