UM PROCEDIMENTO DE CONSULTORIA PARA MELHORAR A GESTÃO DOS PERÍMETROS IRRIGADOS COLETIVOS DO NORDESTE BRASILEIRO

Resumo

Os perímetros irrigados coletivos enfrentam complexos problemas de gestão, para os quais são requeridos procedimentos que se baseiam em técnicas de gestão. Essa abordagem tem por base a representação do funcionamento dos perímetros irrigados, dando enfoque a duas funções centrais: a gestão da água e a tarifação do serviço fornecido aos agricultores. A intervenção, conduzida no perímetro de Maniçoba (região de Petrolina, PE, e Juazeiro, BA), caracteriza-se por uma evolução dinâmica, porém incerta, de seu ambiente e de seus sistemas de produção. Ferramentas de simulação foram elaboradas e um "jogo de papéis" foi conduzido para permitir a reflexão sobre os cenários alternativos para a organização das interações entre a oferta e a demanda de água, e para a escolha de um sistema de tarifação de água. Apresentam se, neste artigo, as reações dos atores diante das simulações realizadas, assim como os aprendizados obtidos, em termos de validação e implementação da intervenção.

Termos para indexação: perímetro irrigado, gestão da água, tarifa, ajuda à tomada de decisão, simulação.

A DECISION-SUPPORT APPROACH FOR IMPROVING
STRATEGIC MANAGEMENT OF COLLECTIVE IRRIGATION
SCHEMES IN NORDESTE (BRAZIL)
ABSTRACT

The management of collective irrigation schemes raises complex issues regarding water management and choice of water pricing. Several approaches have been suggested to tackle these issues, such as systemic analysis or participatory appraisal methods. This paper shows how an approach based on management sciences and intervention-research on the used with the Maniçoba scheme in the Petrolina–Juazeiro area. This case is characterized by a management transfer from a para-statal agency to a water users association called district. This newly established manager has faced major uncertainties that put the scheme viability at risk. Perennial crops have progressively replaced annual crops, altering the farmers' water demand. Both payment defaults and an inadequate water pricing system impact on district's financial balance. The approach aims at supporting the scheme manager addressing strategic issues rather than mere daily operational adjustments. Based on a conceptual framework of collective irrigation scheme management, it focuses on (i) interactions between water supply and demand and (ii) the choice of the water pricing system. In both cases simulation tools have been developed to support prospective reflection by simulating and comparing alternative scenarios. WaDi model calculates the water supply-demand ratio according to changes in hydraulic infrastructure and water management rules, while a second spreadsheet program calculates the impact of water pricing on farmers' incomes and the manager's financial balance. Various ways of improving the small-scale farmers' water supply were compared, e.g. by implementing night irrigation and individual reservoirs. Alternative water pricing systems were simulated in order to increase the district's recipts and to secure coverage of its fixed expenses. It included optional contracts adjusted to different farm types. A role playing game was then organized to improve the stakeholders' understanding and to stimulate discussions regarding the choice and the payment of the water. This approach provides a relevant framework both to understand current scheme operation and to support stakeholders' prospective reflection. Tarify howuver it needs further research regarding the assessment of their assumed learning processes.

Index terms: irrigation scheme, water management, water pricing, decision support, simulation.

UNE DÉMARCHE DE CONSEIL POUR AMÉLIORER
LA GESTION STRATÉGIQUE DES PÉRIMÈTRES IRRIGUÉS
COLLECTIFS DU NORDESTE (BRÉSIL)
RÉSUMÉ

Les périmètres irrigués collectifs posent des problèmes complexes de gestion, nécessitant des démarches d'intervention adaptées. Cet article présente une approche fondée sur les apports des sciences de gestion. Elle part d'un cadre général de représentation du fonctionnement des périmètres irrigués, mettant l'accent sur deux fonctions centrales: la gestion de l'eau et la tarification du service rendu aux agriculteurs. Elle a été appliquée au périmètre de Maniçoba (région de Petrolina-Juazeiro), caractérisé par une évolution dynamique mais incertaine de son environnement et de ses systèmes de production. Des outils de simulation et un jeu de rôle ont été élaborés pour réfléchir à des scénarios alternatifs concernant l'organisation des interactions offre-demande en eau et le choix de systèmes tarifaires. Les réactions des acteurs aux simulations réalisées sont présentées, de même que les enseignements tirés en termes de validation et de mise en œuvre de la démarche.

Termes d'indexation: périmètres irrigués, reseaux d'irrigation, gestion de l'eau, tarification de l'eau, simulation.