The increasing risk of severe droughts and water shortages emphasizes the need for an integrated approach to drought mitigation. However, effective tools for the implementation of such an approach have not been available till now. This book contributes to an improved preparedness for drought in water supply systems, providing tools useful for a better decision making process in drought management. It presents methods and software features of a Decision Support System (DSS) developed within a European research project and consists of three main parts. The first part deals with the advanced techniques for hydrological drought identification and monitoring; the second analyses the successful use of climate-crop-soil models in defining deficit irrigation strategies; the third provides tools for improving the operation of irrigation supply reservoirs. All methods are embedded in a user-friendly DSS package that has been applied in several Case Studies of Mediterranean countries (Portugal, Italy, Tunisia, Jordan and Syria) and whose results are also compared.