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United States Department of Agriculture

Agricultural Research Service

Theodor Strelkoff

Research Hydraulic Engineer


Water Management and Conservation Research Unit

USDA-ARS U.S. Arid-Land Agricultural Research Center



Fedja Strelkoff

Arid-Land Agricultural Research Center

21881 North Cardon Lane

Maricopa, AZ 85238


fax 520-316-6330


Research Hydraulic Engineer



PhD, Fluid Mechanics, State University of Iowa, 1962

MS, Mechanics and Hydraulics, State University of Iowa, 1955

BS, Civil Engineering, City College New York (magna cum laude), 1953


Research Interests:

My principal research goals are to provide tools and methodology for action agencies to apply in design and management recommendations to their clients. For maximum applicability, these tools are based on the fundamental laws of physics, with as little empiricism as possible. These lead to computer models of the phenomena that can be readily exercised in repeated simulations in the search for an optimum. Initial efforts centered on flow in hydraulic control structures, analyzed with potential flow techniques, then on unsteady flow in canals and rivers, including natural and dam-break flooding. The main focus in recent years has been on surface irrigation hydraulics, in particular, simulation of one-dimensional flows in furrows, borders, and basins, under a wide range of conditions, and two-dimensional flows in irregular basins. Corollary software making use of dimensionless representations of flow behavior and providing overviews of border-irrigation performance assists in design and management of border strips. Field-parameter estimation techniques to establish values of infiltration and roughness parameters for the simulation and design software are also of concern. Most recently, the simulation effort has extended to transport of constituents such as eroded soil, phosphorus, and nitrogen in surface fertigation.


Research Projects:

Water Management in Arid Irrigated Agriculture



Selected Publications:

Strelkoff, T. and Shatanawi, M.R.. 1984. Normalized graphs of border-irrigation performance Journal of the Irrigation and Drainage Division, American Society of Civil Engineers, 110(IR4):359-374.

Shatanawi, M.R. and Strelkoff, T.S.. 1984. Management contours for border irrigation. Journal of the Irrigation and Drainage Division, American Society of Civil Engineers, 110(IR4):393-399.

Strelkoff, T.S.. 1985. Dimensionless formulation of furrow irrigation. Journal of Irrigation and Drainage Engineering, Vol. 111(4): 380-394.

Strelkoff, Theodor. 1987. Dam-break flood waves. Megatrends in Hydraulic Engineering. A memorial volume honoring Hunter Rouse. Edited by M.L. Albertson and C.N. Papadakis. Colorado State University, Fort Collins, Colorado.

Strelkoff, Theodor. 1992. EQSWP: Extended unsteady flow double-sweep equation solver. Journal of Hydraulic Engineering, Vol. 118, No. 5, pp. 735-742. May

Strelkoff, Theodor S. and Henry T. Falvey. 1993. Numerical methods used to model canal flow. Journal of Irrigation and Drainage Engineering. 119(4), 637-655

Strelkoff, T. S. and A. J. Clemmens. 1994. Dimensional analysis in surface irrigation. Irrigation Science 15(2/3):57-82.

Al-Azba, A. and Strelkoff, T.S. 1994. Correct form of Hall technique for border irrigation advance. Journal of Irrigation and Drainage Engineering. 120(2) July/August. pp. 292-307.

Burt, C.M., Clemmens, A.J., Strelkoff, T.S., Solomon, K.H., Bliesner, R.D., Hardy, L.A., Howell, T.A., and Eisenhauer, D.E.. 1997. Irrigation performance measures: Efficiency and uniformity. Journal of Irrigation and Drainage Engineering, 123(6):423-442

Strelkoff, T.S., Deltour, J.L., Burt, C.M., Clemmens, A.J., and Baume, J.P. 1998. Influence of canal geometry and dynamics on controllability. Journal of Irrigation and Drainage Engineering, 124(1):16-22

Strelkoff, T.S. and Clemmens, A.J. 1998. Nondimensional expression of unsteady canal flow. Journal of Irrigation and Drainage Engineering, 124(1):59-62

Strelkoff, T.S., A.J. Clemmens, and B.V. Schmidt. 1998. SRFR, Version 3.31 – A model for simulating surface irrigation in borders, basins and furrows. USWCL, USDA/ARS, 4331 E. Broadway, Phoenix, AZ

Clemmens, A.J., El-Haddad, Z., and Strelkoff, T.S. 1999. Assessing the potential for modern surface irrigation in Egypt, Transactions of the American Society of Agricultural Engineers, 42(4):995-1008

Strelkoff, T. S., A. J. Clemmens, M. El-Ansary, and M. Awad. 1999. Surface-irrigation evaluation models: application to level basins in Egypt. Transactions of the ASAE 42(4):1027-1036.

Strelkoff, T. S. and A. J. Clemmens. 2000. Approximating wetted perimeter in a power-law cross section. Journal of Irrigation and Drainage Engineering 126(2):98-109.

Strelkoff, T. S. and D. L. Bjorneberg. 2001. Hydraulic modeling of irrigation-induced furrow erosion. In Stott, D.E., Mohtar, R.H. and Steinhardt, G.C. (eds), Sustaining the Global Farm, Selected papers from the 10th International Soil Conservation Organization Meeting held May 24-29, 1999 at Purdue Univ. and the USDA-ARS Nat’l. Soil Eros. Res. Lab. pp. 699-705

Strelkoff, T. S., A. H. Tamimi, and A. J. Clemmens. 2003. Two-dimensional basin flow with irregular bottom configuration. Journal of Irrigation and Drainage Engineering 129(6):391-401.

Clemmens, A. J., T. S. Strelkoff, and E. Playan. 2003. Field verification of two-dimensional surface irrigation model. Journal of Irrigation and Drainage Engineering 129(6):402-411.

Abbasi, F., J. Simunek, T. van Genuchten, J. Feyen, F. J. Adamsen, D. J. Hunsaker, T. S. Strelkoff, and P Shouse. 2003. Overland Water Flow and Solute Transport: Model development and field-data analysis. Journal of Irrigation and Drainage Engineering 129(2):71-81.

Bautista, E., T. S. Strelkoff, and A. J. Clemmens. 2003. General characteristics of solutions to the open-channel flow feedforward control problem. Journal of Irrigation and Drainage Engineering 129(2):129-137.

Strelkoff, T. S. and A. J. Clemmens. 2005. Transport capacity for eroded silts in irrigation furrows. Journal of Hydraulic Engineering 131(10):921-926.

Bjorneberg, D. L., D. T. Westermann, J. K. Aase, A. J. Clemmens, and T. S. Strelkoff. 2006. Sediment and phosphorus transport in irrigation furrows. J. Environmental Quality. 35:786-794.

Strelkoff, T.S., A.J. Clemmens, and H. Perea-Estrada. 2006. Calculation of non-reactive chemical distribution in surface fertigation. Agricultural Water Management (in press)

Strelkoff, T.S. and A.J. Clemmens. 2006. Hydraulics of surface systems. Chapter 13 in Design and Operation of OnFarm Irrigation Systems. Edited by G.J. Hoffman, R,G. Evans, M.E Jensen, D.L.Martin and R.L. Elliott. 2nd Edition. ASABE Special Monograph. (In press)


Last Modified: 9/19/2007