111-A Decision Model for the Planning and Management of Water on the Basin, Sub-Basin Scale Case Study Western Algarve Water Sub-System (Portugal) .

Abstract

Decision models can be a useful tool for water resources planning and management if an adequate and thorough examination of the problem's circumstances is carried out. For resource management and water allocation problems, relevant documents such as the Agenda 21 of the United Nations Conference on Environment and Development and more recently the European Water Framework Directive, recognize the water basin as the appropriate unit of analysis for integrated water resources management. The decision model used in this work helps the water authorities to decide about water allocation between different uses (e.g. agriculture and urban water supply) on the basin/sub-basin scale. The authors use the Western Algarve water sub-system as their case study. They employed data from a historic decade to evaluate the performance of the water system considering different planning time horizons and objectives for storage in the surface reservoirs at the limit of the planning time horizon. The results showed a high risk situation, at least while a new surface reservoir (the Odelouca dam) is not in operation.