PART I Drought as a natural hazard 1 Introduction 2 Hydroclimatology 3 Drought-generating processes PART II Estimation methods 4 Hydrological data 5 Hydrological drought characteristics 6 Frequency analysis 7 Statistical analysis of drought series 8 Regionalisation procedures e estimation at the ungauged site 9 Process-based modelling PART III Living with drought 10 Human influence 11 Past and future hydrological drought 12 Drought impacts 13 Drought Early Warning Systems: monitoring and forecasting Appendices