The aim of this work is to show out some properties of Guyon's method for drain spacing determination in unsteady state of flow. The analysis has been carried out in the marshy gley soil of the experimental field with drain spacing of 10 m, 20 m and 30 m. The method assumed modeled dynamics of water recharge, which hasn't been observed during the experimental trial. Therefore, its application is limited.

This article represents data of the drainage system functioning at the experimental field "Radmilovac" just after its construction and eleven years later. In the first three years of the system functioning the values of drainage discharge, water table depth and soil moisture content were in the range which characterizes satisfactorily drained soil.

The aim of this work is to show some properties of the application of Kraijenhoff Van de Leur-Maasland’s method for drain spacing determination in unsteady state of flow. The analysis of the method is based on data obtained from drainage field with 10 m of drain spacing which dries out eugley soil. The results of analysis show the range of method applicability as well as certain limitations in the case of non-modelled dynamics of ground water recharges.

Dagan’s method as well as Kirkham’s one belong to the group of methods for drain spacing determination in steady state water flow conditions. Both methods are based on the assumption that drainage spacing (L) is linear function of water table depth and drainage discharge (h/q). The only difference can be distinguished in the values of coefficients. To dry out eugley type of soil, drain spacing is better determined by Dagan’s method in all treatments, as compared with Kirkham’s one.

The aim of this work is to present some peculiarity of Kirkham’s method applied in drain spacing determination in steady state water flow in eugley soil type. The analysis was based on data obtained by measuring water discharge from drains and water table depth. Measurements was carried out on drainage field with drain spacing of 10 m, 20 m and 30 m, representing drainage treatments I, II and III, respectively. The estimation of drain spacing is moved to lower value in all treatments.

The aim of this research was to figure out certain limitations of methods for drain spacing determination application in unsteady-state of flow rate to the drains in the eugley soil. The well-known Glover-Dumm method was taken in this analysis. The analysis was based on the results of drain discharge and water table depth measurements. Measurements were carried out on the experimental field.