What is Arc Hydro?

David Maidment, CRWR

Arc Hydro is a geospatial and temporal data model for water resources designed to operate within ArcGIS (Maidment, 2002).  A data model is distinct from a simulation model in that a data model provides a standardized framework for storing information, but contains no routines to simulate hydrologic processes. The data model is typically coupled with one or more simulation models with data and information being transferred from Arc Hydro to a model and results being returned to Arc Hydro.  Arc Hydro, therefore, provides a means for linking simulation models through a common data storage system.  Map2Map, an application created at the Center for Research in Water Resources, is an example of how Arc Hydro can be used to link two simulation models, in this case HEC's HMS and RAS models. 

Of course the best way to learn about Arc Hydro is by trying Arc Hydro.  I teach a GIS in Water Resources class at the University of Texas at Austin each year, and the exercises for this class are included here.  They cover introductory material to familiarize those new to ArcGIS and specialized exercises on working with the Arc Hydro TimeSeries component. 

Another excellent resource is Arc Hydro: GIS for Water Water Resources that I edited.  The book provides a detailed description of the components within Arc Hydro and how to implement Arc Hydro for a river basin.

Finally, I encourage you to visit the http://www.esri.com/datamodels/hydro where you can find the data model itself, a tutorial for implementing Arc Hydro, and an example Arc Hydro geodatabase compiled for the Guadalupe River Basin.

References:

Maidment, D. R., ed., 2002. Arc Hydro: GIS for Water Resources, ESRI Press, Redlands, Ca.