Published by the American Geophysical Union as part of the Water Science and Application Series, Volume 9. Groundwater recharge, the flux of water across the water table, is arguably the most difficult component of the hydrologic cycle to measure. In arid and semiarid regions the problem is exacerbated by extremely small recharge fluxes that are highly variable in space and time. --from the Preface Groundwater Recharge in a Desert Environment: The Southwestern United States speaks to these issues by presenting new interpretations and research after more than two decades of discipline-wide study. Discussions ondeveloping environmental tracers to fingerprint sources and amounts of groundwater at the basin scalethe critical role of vegetation in hydroecological processesnew geophysical methods in quantifying channel rechargeapplying Geographical Information System (GIS) models to land surface processescoupling process-based vadose zone to groundwater modeling, and more make this book a significant resource for hydmlogists, biogeoscientists, and geochemists concerned with water and water-related issues in arid and semiarid regions.