Multi criteria decision analysis for water resources management in the Gediz River Basin

In this study, a water resources management model that facilitates indicator-based decisions with respect to environmental, social and economic dimensions in a multiple criteria perspective is developed for the Gediz River Basin in Turkey. The basic input of the proposed model is the quantity of surface water that is greatly allocated to irrigation purposes; therefore, supply and demand interrelations in agricultural water use constitute the main focus of the study. The model has been applied under three different hydro-meteorological scenarios that reflect baseline as well as better and worse conditions of water supply and demand, not only to reach a comprehensive assessment of water budget in Gediz Basin, but also to evaluate the impacts of proposed management alternatives under different conditions.The results of the study have indicated that the Gediz River Basin is quite sensitive to drought conditions, and the agricultural sector is significantly affected by irrigation deficits that increase sharply in drought periods. Even if the optimistic scenario is assumed to occur, it is not possible to observe a significant improvement in the water budget; however, the negative impacts of climate change can possibly exacerbate the water crisis. The management alternative that combines the replacement of the current water distribution network by piped systems to decrease water losses and the use of `water saver? technologies such as drip irrigation to improve irrigation efficiency is determined as `best? alternative with respect to environmental, social and economic dimensions through the use of a multi criteria approach.