TY - GEN

T1 - Modified two-point method for closed-end level-bed furrows

AU - Zerihun, D.

AU - Sanchez, C. A.

AU - Farrell-Poe, K. L.

PY - 2004/12/1

Y1 - 2004/12/1

N2 - The two-point method is a simple, compact, and relatively accurate inverse solution technique widely used to estimate the parameters of the Kostiakov-Lewis infiltration function. However, the applicability of the method is limited to sloping free-draining furrows. In this paper, the two-point method is modified to extend its application to close-end level-bed furrows. The modifications deal with the calculation of the basic intake rate and the inlet flow cross-sectional area during the advance phase. With the modified method, basic intake rate is calculated as the quotient of the change in volumetric surface storage between two selected time lines during the steady state period and the product of the furrow length and related time interval. In addition, the inlet flow cross-sectional area can be calculated as a function of flow depth at the inlet or using the Manning equation and an assumed linear flow depth gradient. The proposed approach was tested by comparing advance trajectories computed by SRFR, on the basis of infiltration parameter estimates by the modified two-point method, with field observed advance. A satisfactory agreement was obtained between SRFR predicted and field observed advance.

AB - The two-point method is a simple, compact, and relatively accurate inverse solution technique widely used to estimate the parameters of the Kostiakov-Lewis infiltration function. However, the applicability of the method is limited to sloping free-draining furrows. In this paper, the two-point method is modified to extend its application to close-end level-bed furrows. The modifications deal with the calculation of the basic intake rate and the inlet flow cross-sectional area during the advance phase. With the modified method, basic intake rate is calculated as the quotient of the change in volumetric surface storage between two selected time lines during the steady state period and the product of the furrow length and related time interval. In addition, the inlet flow cross-sectional area can be calculated as a function of flow depth at the inlet or using the Manning equation and an assumed linear flow depth gradient. The proposed approach was tested by comparing advance trajectories computed by SRFR, on the basis of infiltration parameter estimates by the modified two-point method, with field observed advance. A satisfactory agreement was obtained between SRFR predicted and field observed advance.

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M3 - Conference contribution

AN - SCOPUS:23844535187

SN - 0784407371

SN - 9780784407370

T3 - Proceedings of the 2004 World Water and Environmetal Resources Congress: Critical Transitions in Water and Environmetal Resources Management

SP - 1680

EP - 1688

BT - Proceedings of the 2004 World Water and Environmetal Resources Congress

A2 - Sehlke, G.

A2 - Hayes, D.F.

A2 - Stevens, D.K.

T2 - 2004 World Water and Environmental Resources Congress: Critical Transitions in Water and Environmental Resources Management

Y2 - 27 June 2004 through 1 July 2004

ER -