Robert M. Hirsch (born June 6, 1949) is a research hydrologist and a former Associate Director for Water of the U.S. Geological Survey.
As Associate Director (also known as Chief Hydrologist), he was responsible for the water science programs of the USGS.
He served as the leader of USGS water science from 1994 to 2008 when Dr. Hirsch transitioned to the USGS National Research Program to rededicate himself to advancing the science on critical issues of climate change and long-term trends in water resources.
He began his USGS career in 1976 as a hydrologist and has conducted research on water quality statistical methods (trends and fluxes), water supply reliability, and flood frequency analysis.
He earned a bachelor of arts in Geology at Earlham College in 1971, an MS in Geology at the University of Washington in 1974, and a Ph.D. from The Johns Hopkins University from the Department of Geography and Environmental Engineering in 1976.