An Indicator Based Assessment for Water Resources Management in Gediz River Basin, Turkey

In this study, a water resources management model that facilitates indicator‐based decisions with respect to environmental, social and economic dimensions 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 an assessment of water budget, but also to evaluate the impacts of proposed management alternatives under different conditions. The Water Evaluation and Planning (WEAP) software is used as a simulation and evaluation tool to assess the performance of possible management alternatives, which is measured by nine proposed indicators. 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 indicators also verified that, efficient water management is crucial to ensure the sustainable use of water resources with respect to environmental, social and economic dimensions.