Subsurface drainage of a three layered soil with slowly permeable top layer

Heavy textured soils are known for the difficulties imposed to subsurface d rainage. Field studies on heavy textured soils in the irrigation commands o f India have shown that such soils have relatively more pervious soil at de pths greater than 1 m from the ground surface. Considering this fact, a per formance study of subsurface drainage in heavy textured layered soils of Ma hi Right Bank Canal Command of Gujarat (India) was taken up by modifying th e drainage equation of de Zeeuw and Hellinga [de Zeeuw, J.W., Hellinga, F., 1958. Neerslag en Afvoer, Land bocwkundig Tidschrift 70, 405-421] for laye red soils, which predicted the water table fluctuations and drain discharge corresponding to irrigation or rainfall inputs taking into account the str atification of the soil profile. The equation was tested on the field data obtained from a pilot project of the study area. The study showed that the watertable head gets influenced by the location of interface between the so il layers. The predicted results conformed with the field data. (C) 1999 El sevier Science B.V. All rights reserved.