This book (the research outcome of the EU-INCO FP6 research project Jayhun: Interstate Water Resource Risk Management: Towards a Sustainable Future for the AralBasin) focuses on and discusses the results of research done on the risk assessment levels associated with relevant regional variables in the Aral Basin and develops a strategy for an improved management of the regions water resources. The book provides current and reliable information on the rate of glacial retreat in Central Asian and the implications for future water resources in the region. The impact of global changes on annual precipitation is assessed. The rates of reservoir siltation are established by hydrographic surveys, and analyses of wastage and effectiveness of water usage in the large irrigation massifs are conducted. Water resources models are used to analyse existing and newly generated data. These are calibrated with existing data and subsequently used for simulating various possible future scenarios. The book thereby provides a risk analysis for water resources management in the Aral Basin and identifies sustainable options for improved management of the regions water resources.