Geographical Information Systems (GIS) are used to display, manipulate and analyse spatial (map) data. ArcGIS (produced by ESRI) is an integrated collection of software products for building a complete geographic information system (GIS). There are three ArcGIS desktop applications - ArcCatalog, ArcMap, and ArcToolbox. ArcCatalog is the application for managing your spatial data holdings, for managing your database designs, and for recording and viewing metadata. ArcMap is used for all mapping and editing tasks, as well as for map-based analysis. ArcToolbox is used for data conversion and geoprocessing. Using these three applications together, you can perform any GIS task, simple to advanced, including mapping, data management, geographic analysis, data editing, and geoprocessing. There are also server-based ArcGIS products, as well as ArcGIS products for PDAs. Extensions can be purchased separately to increase the functionality of ArcGIS.

GIS is a powerful tool for developing solutions for water resources such as assessing water quality and managing water resources on a local or regional scale. Hydrologists use GIS technology to integrate various data and applications into one, manageable system. ArcGIS with Arc Hydro gives you the flexibility to combine watershed datasets from one map source with stream and river networks. The suite of tools contained in Arc Hydro facilitate the creation, manipulation, and display of hydro features and objects within the ArcGIS environment. Use ArcGIS Spatial Analyst for hydrologic analysis such as calculating flow across an elevation surface, which provides the basis for creating stream networks and watersheds; calculating flow path length; and assigning stream orders.

This group aims to provide a forum for exchange of ideas and experiences regarding application of GIS in Hydrology and Water Resources; and use of ArcGIS software (in general) and Arc Hydro (in particular).