The Hydrologic Sciences Program focuses on the fluxes of water in the environment that constitute the water cycle as well as the mass and energy transport function of the water cycle. The Program supports the study of processes from rainfall to runoff to infiltration and streamflow; evaporation and transpiration; the flow of water in soils and aquifers; and the transport of suspended, dissolved, and colloidal components. The Hydrologic Sciences Program retains a strong focus on linking fluxes of water and the components carried by water across boundaries between various interacting facets of the terrestrial system and the mechanisms by which these fluxes co-organize over a variety of timescales and/or alter fundamentals of water cycle interactions within the terrestrial system. The Program is also interested in how water interacts with the landscape and the ecosystem as well as how the water cycle and its coupled processes are altered by land use and climate. Studies may address physical, chemical, and biological processes that are coupled directly to water transport. Projects submitted to Hydrologic Sciences commonly involve expertise from basic sciences, engineering and mathematics; and proposals may require joint review with related programs. The Hydrologic Sciences Program will also consider synthesis projects.