Theories of Ditch Drainage in Layered Anisotropic Soil

Approximate theoretical formulas are derived for predicting the water table position for steady rainfall or steady irrigation recharge into soil bounded by equally spaced ditch drains dug up to an impervious layer in single-, two-, and three-layered anisotropic soils. The ditch drainage problem is first solved for the single-layered case and subsequently, solutions are obtained to the twoand three-layered cases of the problem. All the solutions are based on exact mathematical procedures but utilize a physical assumption that the head loss in the arch-shaped region of the water table is negligible compared with the head loss for the remainder of the region. A correction, however, is provided to account for this head loss for all the solutions and the corrected formulas are found to be on the “safe side” for drainage design since the water table heights predicted by these formulas are higher than the actual ones. The accuracy of the proposed solution to the single-layered problem is tested by comparing it w...

[1]  L. S. Willardson,et al.  Artesian and Anisotropic Effects on Drain Spacing , 1986 .

[2]  R. Herbert.  Modelling Partially Penetrating Rivers on Aquifer Models , 1970 .

[3]  E. C. Childs.  An introduction to the physical basis of soil water phenomena , 1969 .

[4]  E. J. List.  The steady flow of precipitation to an infinite series of tile drains above an impervious layer , 1964 .

[5]  J. C. Miles,et al.  New Drain Flow Formula , 1989 .

[6]  E. G. Youngs,et al.  Horizontal seepage through unconfined aquifers with hydraulic conductivity varying with depth , 1965 .

[7]  D. Kirkham,et al.  STEADY DRAINAGE OF LAYERED SOILS: I, THEORY , 1971 .

[8]  E. G. Youngs,et al.  A comparison of steady-state land-drainage equations , 1984 .

[9]  D. Kirkham,et al.  Graphical Solution and Interpretation of a New Drain-Spacing Formula , 1961 .

[10]  E. C. Childs.  THE WATER TABLE, EQUIPOTENTIALS, AND STREAMLINES IN DRAINED LAND: II , 1943 .

[11]  Gedeon Dagan.  Steady Drainage of a Two-Layered Soil , 1965 .

[12]  Gautam Barua,et al.  Theories of seepage into auger holes in homogeneous anisotropic soil , 1995 .

[13]  Gautam Barua,et al.  Analytical Solutions of Seepage into Ditches from Ponded Fields , 1995 .

[14]  D. Kirkham,et al.  Seepage of steady rainfall through soil into drains , 1958 .

[15]  E. G. Youngs,et al.  Water-table heights in drained anisotropic homogeneous soils , 1986 .

[16]  M Muskat,et al.  THE FLOW OF HOMOGENEOUS FLUIDS THROUGH POROUS MEDIA: ANALOGIES WITH OTHER PHYSICAL PROBLEMS , 1937 .

[17]  E. C. Childs.  A treatment of the capillary fringe in the theory of drainage. II. Modifications due to an impermeable sub-stratum. , 1960 .

[18]  E. G. Youngs,et al.  THE NATURE OF THE DRAIN CHANNEL AS A FACTOR IN THE DESIGN OF A LAND‐DRAINAGE SYSTEM , 1958 .

[19]  W. L. Powers,et al.  Advanced soil physics , 1972 .

[20]  P. Eckerlin,et al.  W. B. Pearson: The Crystal Chemistry and Physics of Metals and Alloys. Wiley‐Interscience, John Wiley & Sons, Inc., New York‐London‐Sydney‐Toronto 1972. 806 Seiten, Preis: , 1972 .

[21]  E. G. Youngs,et al.  The effect of the depth of an impermeable barrier on water-table heights in drained homogeneous soils , 1975 .

[22]  E. C. Childs.  A TREATMENT OF THE CAPILLARY FRINGE IN THE THEORY OF DRAINAGE , 1959 .

[23]  L. K. Smedema,et al.  Use of the Hooghoudt formula for drain spacing calculations in homogeneous-anisotropic soils , 1985 .

[24]  W. F. Beers.  Computing drain spacings , 1976 .

[25]  D. Kirkham.  Explanation of paradoxes in Dupuit‐Forchheimer Seepage Theory , 1967 .