Water Productivity and Food Security: Global Trends and Regional Patterns, Volume Three reviews the need for water productivity improvements in agriculture, addressing three distinct questions pertaining to agricultural water productivity improvement in developing countries, including what are the regions where water is a limiting factor for raising agricultural outputs and water productivity improvements, what are the technological measures in irrigation that can raise agricultural water productivity and result in water saving at various scales, and what opportunities exist in the developing economies of South Asia and Africa for raising water productivity and improving water economy at basin scale. This book provides a framework to characterize river basins based on water availability, water supplies, water uses and water demands to ascertain the need and measures available for improving crop water productivity that would be effective at various scales, i.e., plant-level, plot-level, irrigation system level and basin level. This is an essential reference for anyone interested in water management and agriculture.