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Cowan's Method for Estimating Roughness $n$

Method Summary
Figure 4: Cowan method for determining roughness coefficient $n$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-11

Basic $n$

Figure 5: Cowan basic roughness value $n_1$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-5

Channel Irregularity

Figure 6: Cowan adjustment for channel irregularity $n_2$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-6

Cross-Section Changes

Figure 7: Cowan adjustment for channel cross-section changes $n_3$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-7

Obstructions

Figure 8: Cowan adjustment for channel obstructions $n_4$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-8

Vegetation

Figure 9: Cowan adjustment for vegetation $n_5$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-9

Meandering

Figure 10: Cowan adjustment for channel meandering $n_6$ (Cowan, 1956; McCuen, 2004).
Image mccuen-1998_tbl3-10


next up previous
Next: Limitations/Extensions of Manning Equation Up: Manning's Roughness Coefficient Previous: Introduction
GEOS 5313 Lecture Notes, Spring 2007
Dr. T. Brikowski, UTD. All rights reserved.