An empirical method of determining momentary discharge of tide-affected streams

This report demonstrates a new approach to the difficult and perplexing problem of of determining the momentary discharge of tide-affected streams. The instruments used are standard and consist of a stage recorder at each end of a reach of estuary. The 10.8-mile reach of Sacramento River between gages at Sacramento and Freeport was selected for study, and the required rating curves were derived by use of the coaxial method of graphical multiple correlation. The dependent variable in the correlation is discharge at Sacramento; the independent variables are (1) stage at Sacramento, (2) fall in the reach between Sacramento and Freeport, and (3) algebraic average of the rate of change of stage observed at Sacramento and Freeport.