ArcGIS Spatial Analyst contains specialized tools for working with and deriving new information from hydrologic and landscape data.
Its toolset includes methods for describing hydrologic characteristics and tools to calculate flow across an elevation surface, calculate flow path length, and assign stream orders. These kinds of derived data are often used to aggregate landscape information for input to hydrologic models.
The groundwater tools can be used to perform simple 2D advection-dispersion modelling of groundwater flow and constituents in groundwater. The Darcy Flow tool generates a groundwater flow field from hydrogeological data. The Particle Track tool follows the path of advection (movement) through the flow field from a point source, and the Porous Puff tool calculates the dispersion of a chemical or constituent as it is moved along the flow path.