where c and d are recession constants depending on the
catchment physical characteristics. In the storage-discharge
relationship, d = 1 indicates a linear reservoir; otherwise, the
reservoir is nonlinear when d ≠1. They can also be expressed in
the form of the baseflow coefficients ae andbe (c =
1/[ae (2-be )], d= 2-be ).
Combining equations (2) and (3), the relationship between the streamflow
and flow variation affected by environmental changes can be derived as
follows: