In arid and semiarid areas in the world, including the Mediterranean region, groundwater has been widely and intensively used for irrigation over the last few decades. Practical as well as economic reasons make its use much more preferable, as compared to surface water, especially to individual farmers. Yet, this rapid and largely uncontrolled expansion in groundwater exploitation, which stimulated the socioeconomic development of numerous rural communities, has produced many negative impacts on aquifer degradation and environmental deterioration. The most common remedy to such problems is the application of specific groundwater management policies that can simultaneously meet socioeconomic and environmental protection goals. In this sense, the paper introduces a methodology for an optimal management of irrigation water, by specifically exploring the socioeconomic and environmental impacts of spatially allocated water conservation measures at the watershed level. The analysis is conducted by developing a multi-criteria decision-making framework, consisting of three distinct models: a hydrogeological, an optimization, and a multi-criteria one, which appraises the results of the other two. The proposed methodology is presented through a case study at a rural Greek watershed, in which groundwater is the sole water source for an intensively practiced agriculture. A system of water use quotas is the resource conservation policy instrument that is examined under a decision-making approach. Results show that some specifically designed and spatially non-uniform quota allocation schemes can meet in an optimum way the relevant criteria.Additional key words: crop-water functions; sustainable irrigation water management; water quotas; watershed model; weighted summation.
ResumenUso combinado de análisis multicriterio y simulación de aguas subterráneas dentro de un marco espacial de toma de decisiones para la asignación óptima del agua de riego Las aguas subterráneas se han usado intensivamente en las regiones áridas y semiáridas del planeta, incluyendo el Mediterráneo. Hay razones económicas y prácticas que las hacen preferibles a las aguas superficiales, especialmente para agricultores individuales. Sin embargo esto ha conducido a una expansión incontrolada del uso de aguas subterrá-neas que ha estimulado el desarrollo de muchas comunidades rurales, pero que ha producido impactos negativos como degradación en acuíferos y deterioro ambiental. El remedio más común para estos problemas es la aplicación de políti-cas de gestión de aguas subterráneas que busque satisfacer simultáneamente los objetivos ambientales y socioeconómi-cos. Este trabajo introduce una metodología explorando los impactos ambientales y socioeconómicos de una asignación de recursos a nivel de acuífero. El análisis se hace desarrollando un esquema multicriterio consistente en tres modelos: hidrogeológico, optimización, y función multicriterio, que evalúa los resultados de los otros dos. La propuesta se aplica a un estudio del caso de un acuífero rur...