Groundwater datasets
In the United States, data depicted on blue lines, the color of surface water features on topographic maps, have been compiled by the Unites States Geological Survey (USGS) into seamless national hydrography datasets at scales of 1:100,000 and 1:24,000, but no equivalent national hydrogeology dataset exists. Subsurface hydrogeologic data are measured and archived by many federal, state, and local groundwater agencies in a fragmented way without a common means of data access and synthesis. The lack of a systematic organization of hydrogeologic and groundwater data means that their formats vary from state to state, from location to location, and from project to project. A new groundwater investigation can be like an Easter egg hunt, where you search around for the basic data needed to support the investigation, coping with many disparate data types and formats from different data sources. We envisage that the adoption of the Arc Hydro Groundwater data model will lead to better organization of groundwater data so that standardized groundwater and hydrogeologic datasets can be systematically compiled and maintained. Since hydrogeology is a subfield of geology, it is appropriate that Arc Hydro Groundwater has a geology component to allow for incorporating existing geologic maps and data into Arc Hydro Groundwater datasets. The ArcGIS Desktop software system is the key means by which groundwater information is compiled and synthesized in Arc Hydro Groundwater. However, this is now being supplemented by ArcGIS Server and ArcGIS Online, by which compiled Arc Hydro datasets can be published on the Internet as maps and data services. This emerging “services-oriented architecture” for geospatial information is an important way for separate organizations to publish geographically distributed groundwater datasets in a manner that facilitates their assembly and integration over a region.