This book is a hard copy of the editorial and all the papers in a Special Issue of the peer-reviewed open access journal ‘Water’ on the theme ‘Managed Aquifer Recharge for Water Resilience’. Managed aquifer recharge (MAR) is the purposeful recharge of water to aquifers for subsequent recovery or environmental benefit. MAR is increasingly used to make water supplies resilient to drought, climate change and deteriorating water quality, and to protect ecosystems from declining groundwater levels. Global MAR has grown exponentially to 10 cu.km/year and will increase ten-fold within a few decades. Well informed hydrogeologists, engineers and water quality scientists are needed to ensure that this investment is effective in meeting increasingly pressing needs. This compilation contains lessons from many examples of existing projects, including several national and continental summaries. It also addresses the elements essential for identifying and advancing projects such as mapping aquifer suitability and opportunities, policy matters, operational issues, and some innovations in MAR methods and monitoring. This collection exemplifies the state of progress in the science and practice of MAR and is intended to be useful, at least to water managers, water utilities, agricultural water users and urban planners, to facilitate water resilience through new MAR projects.

The Green Technology Book puts innovation, technology and intellectual property at the forefront in the fight against climate change. This inaugural edition focuses on three important areas: agriculture and forestry, water and coastal regions, and cities, showcasing 200 available solutions that aim to reduce vulnerability and increase resilience to climate impacts.

Research Reports The publications in this series cover a wide range of subjects—from computer modelling to experience with water user associations—and vary in content from directly applicable research to more basic studies, on which applied for work ultimately depends. Some research reports are narrowly focused, analytical and detailed empirical studies; others are wide-ranging and synthetic overviews of generic problems. Although most of the reports are published by IWMI staff and their collaborators, we welcome contributions from others. Each report is reviewed internally by IWMI staff, and by external reviewers. The reports are published and distributed both in hard copy and electronically (www.iwmi.org) and where possible all data and analyses will be available as separate downloadable files. Reports may be copied freely and cited with due acknowledgement