Robert E. Horton Medal

The Robert E. Horton Medal is given out by the American Geophysical Union to recognize "outstanding contributions to the geophysical aspects of hydrology". The award was created in 1974 and named after Robert E. Horton to honor his contributions to the study of the hydrologic cycle. It was awarded biennially until 1995 and then annually thereafter. 
Past recipients.
Source: American Geophysical Union