Double-mass curve

What is Double-mass curve?

Double-mass curve meaning The drainage area of a stream at a specified location is that area, measured in a horizontal plane, which is enclosed by a drainage divide. (See [U.S.] Federal Inter-Agency River Basin Committee, Subcommittee on Hydrology, 1951, p. 11. ) 1

 

reference: USGS – Water Basics Glossary