USE OF LINEAR REGRESSION FOR THE PREDICTION OF THE SUSPENDED SEDIMENT LOAD IN THE CUYAHOGA RIVER AT OLD PORTAGE GAUGING STATION, NORTHEASTERN OHIO

This study employs linear regression for the prediction of the suspended sediment load in the Cuyahoga River at Old Portage gauging station, in northeastern Ohio, based on river water discharge. The suspended sediment load and river water discharge data are published by the U.S. Geological Survey. The data covered a period of approximately 10 years between 1972 and 1981. The drainage area above the gauging station at Old Portage is 404 mi².

Two approaches were used to calculate the suspended sediment load, the dependent variable, as a function of river water discharge, the independent variable. The first approach estimates the annual suspended sediment load as the sum of the monthly suspended sediment loads, which were determined by linear regression using the monthly water discharges. The correlation coefficient of the monthly regression relationship is 0.79. In the second approach, the regression utilizes the annual water discharges to directly calculate the annual suspended sediment load. The correlation coefficient of the annual regression relationship is 0.69, which is not significantly different from the monthly value.

The two approaches yielded comparable accuracy of predicting the suspended sediment load. The mean percent deviation (absolute value of the difference between the observed and predicted sediment loads) obtained by the two approaches is about 15%. Therefore, either approach can be used to predict the suspended sediment load using linear regression.