Application of a GIS-based Simulation Tool to Analyze and Communicate Uncertainties in Future Water Availability in the Amudarya River Delta

Simulation and decision support tools facilitate a process of reasoning about potential future development paths of a system, e.g. a river system, under alternative management strategies. Joint scenario development and analysis with river basin authorities and stakeholders can inform and structure discussions on management goals and major uncertainties affecting river basin management in future. Tools can support the determination of strategies that balance water allocation between multiple users, such as irrigation and the environment, and measures to cope with uncertainties. The GIS-based simulation tool TUGAI has been developed to facilitate exploration of alternative water management strategies for the degraded Amudarya river delta and to analyze their ecological implications. It combines a multi-objective water allocation model with simple models of landscape dynamics and a fuzzy based assessment of habitat changes for riverine Tugai forests. The Tugai forests serve as an indicator of the ecological state of the delta region under a given water management scenario. In this contribution different sources of uncertainties in water availability for the Amudarya delta will be determined and the ecological implications of water supply uncertainty analyzed using the TUGAI tool. Scenario analysis provides an assessment of the range and magnitude of the impact of those uncertainties on the ecological situation in the delta. Uncertainties inherent in system understanding and representation that influence model outcomes are presented and discussed in view of their role in the impact assessment. The application of simple simulation tools that integrate the up to date available knowledge of the system for identification of the type and range of relevant uncertainties affecting river basin management and their perception with managers and stakeholders, for analysis and discussion of their potential impacts and development of cooping strategies will be discussed.