USGS Scientific Investigations Report 2012–5200  - Suspended-Sediment Characteristics of the Johnson Creek Basin, Oregon, Water Years 2007

Table 2. Diagnostic test performance of various regression equations for estimating suspended‑sediment concentration to streamflow and turbidity, Johnson Creek basin, Oregon, water years 2007–10. 

[Station reference: Complete station names are shown in table 1 and locations are shown in figure 1. Variables: Log, log base 10; Q, streamflow, in cubic feet per second; Sqrt, square root; SSC, suspended-sediment concentration; T, turbidity, in Formazin Nephelometric Units (FNU). Diagnostic linear regression statistics: Adj R², adjusted coefficient of determination; RMSE, root mean squared error; MAE, mean absolute error; MAPE, mean absolute percent error. Evaluation of linear regression model residuals: JB, P-value of Jarque-Bera test statistic; BP, P-value of Breusch-Pagan test statistic] 

	Variables		Diagnostic linea regression statistics				Evaluation of linear regression model residuals
	Dependent	Independent	Adj R²	RMSE	MAE	MAPE	JB	BP
Gresham
Model 1	SSC	T	0.81	36.5	27.2	0.22	0.125	0.056
Model 2	SSC	Q	0.71	44.8	34.5	0.29	0.211	0.627
Model 3	SSC	Q,T	0.90	25.3	20.8	0.16	0.261	0.001
Model 4	Log SSC	Log T	0.86	40.8	30.4	0.21	0.230	0.007
Model 5	Log SSC	Log Q	0.71	47.2	37.1	0.27	0.000	0.367
Model 6	Log SSC	Log T, Log Q	0.94	27.1	21.3	0.14	0.175	0.001
Model 7	Sqrt SSC	Sqrt T, Sqrt Q	0.93	25.1	20.2	0.14	0.187	0.001
Milwaukie
Model 1	SSC	T	0.81	45.2	37.2	0.24	0.371	0.045
Model 2	SSC	Q	0.45	77.1	60.5	0.47	0.873	0.922
Model 3	SSC	Q,T	0.80	45.2	37.4	0.25	0.337	0.094
Model 4	Log SSC	Log T	0.84	47.4	38.9	0.23	0.261	0.012
Model 5	Log SSC	Log Q	0.59	75.5	53.4	0.33	0.913	0.804
Model 6	Log SSC	Log T, Log Q	0.84	51.3	41.0	0.23	0.049	0.004
Model 7	Sqrt SSC	Sqrt T, Sqrt Q	0.83	164	128	0.23	0.335	0.016

Both stations	Variables	Average rank
Model 1	T	3.8
Model 2	Q	6.3
Model 3	Q,T	2.8
Model 4	Log T	3.5
Model 5	Log Q	6.3
Model 6	Log T, Log Q	2.3
Model 7	Sqrt T, Sqrt Q	3.3

Suspended-Sediment Characteristics of the Johnson Creek Basin, Oregon, Water Years 2007–10

Suspended-Sediment Characteristics of the Johnson Creek Basin, Oregon, Water Years 2007–10 