The hydrologic cycle describes how water continuously moves between the atmosphere, land, and ocean. Evaporation, transpiration, condensation, precipitation, runoff, infiltration and exchange with groundwater are the processes that control surface water flow in a drainage basin. The amount of flow in a watershed, in turn, is determined by topography, types of soils and land uses. While emphasis is placed on studies of the hydrological cycle, hydrology also deals with the biological, chemical, and physical interatctions of water in all its phases. AWAE pursues basic research on hydrology, hydraulics, hydrometeorology, and hydroclimatology. Our goal is to advance the science and to facilitate, promote, and make feasible the use of findings in applications for which water is important.