Hydrological Drought: Processes and Estimation Methods for Streamflow and Groundwater, Second Edition provides a comprehensive review of processes and estimation methods for streamflow and groundwater drought. It includes a qualitative conceptual understanding of drought features and processes, a detailed presentation of estimation methods and tools, practical examples and impacts relevant for operational practice. The drought phenomenon and its diversity across the world are illustrated using a global set of daily streamflow series, whereas regional and local aspects of drought are studied using a combination of hydrological time series and catchment information. Hydrological Drought: Processes and Estimation Methods for Streamflow and Groundwater, Second Edition concludes with human impacts, including climate change impacts on drought, drought forecasting and early warning and examples of procedures on how to manage water during drought. The majority of the examples are taken from regions where the rivers run most of the year, but not exclusively. The material presented ranges from well-established knowledge and analysing methods to recent developments in drought research. Its nature varies accordingly, from a more traditional textbook and clear overview to that of a research paper, which introduces recent approaches and methodologies for drought analysis.