GIS and hydrology

Geographic information systems (GISs) have become a useful and important tool in the field of hydrology to study and manage Earth's water resources.

Historical and real-time streamflow data are also available via the internet from sources such as the National Weather Service (NWS) and the United States Environmental Protection Agency (EPA).

Using digital elevation models combined with peak discharge data can predict which areas of a floodplain will be submerged depending on the amount of rainfall.

In a study of the Illinois River watershed, Rabie (2014)[6] found that a decently accurate flood risk map could be generated using only DEMs and stream gauge data.

Analysis based on these two parameters alone does not account for manmade developments including levees or drainage systems, and therefore should not be considered a comprehensive result.

USGS real-time streamflow gage locations with hyperlinks within a GIS to the data
A digital elevation model (DEM) from which a watershed may be delineated within a GIS
Groundwater level change of the High Plains Aquifer, 1980–95