online_lane_shape:  Equilibrium shape of self-formed channels in noncohesive alluvium using the Lane et al. theory The Mississippi river near Lake Bemidji, Minnesota Formula: To = Yo  cos-1 (β tanφ ) • [2 / tanφ] • [(1 + β tanφ ) / (1 - β tanφ )]1/2 Reference:  Ponce, V. M. and S. Jiang, 2020. The equilibrium shape of self-formed channels in noncohesive alluvium.  SI Units (metric):   Flow depth Yo in m; friction angle φ in degrees; β is dimensionless.   U.S. Customary Units:   Flow depth Yo in ft; friction angle φ in degrees; β is dimensionless.  INPUT DATA: Select:       SI units (metric) U.S. Customary units Flow depth Yo  (at channel centerline):           Warning: Undefined variable $flowdepthunits in /var/www/html/ponce/onlinelaneshape.php on line 181 Friction angle φ  (repose angle):                   [Recommended range:  5o ≤ φ ≤ 45o]   Warning: Undefined variable $anglephiunits in /var/www/html/ponce/onlinelaneshape.php on line 185 Ratio of lift force to drag force β :                  [Recommended range:  -1 ≤ β ≤ 1]   OUTPUT: Channel top width To :    Warning: Undefined variable $topwidth in /var/www/html/ponce/onlinelaneshape.php on line 199 Deprecated: substr(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/html/ponce/onlinelaneshape.php on line 199   Warning: Undefined variable $topwidthunits in /var/www/html/ponce/onlinelaneshape.php on line 199 Press button to     or recalculate   Your request was processed at  04:26:53 am on April 3rd, 2025   [ 250403  04:26:53 ]. Thank you for running   online_lane_shape   Please call again.   [201107]