A comparative study of hydraulic conductivity in the alluvial soils of egypt

Abstract

It is the first approach to use the auger hole method for measuring the hydraulic conductivity of substrata in the alluvial soils of Egypt. The determinations have been conducted at auger hole depths of 140 and 200 cm. Soil samples were removed from the auger holes below the water table every 10 cm. Hydraulic conductivity values are obtained by both auger and undisturbed soil core methods. Permeability values of different types of alluvial soils of Egypt have been given. Almost the same hydraulic conductivity value is calculated by three methods. Only for soils with high water tables Kirkham method fails to calculate the hydraulic conductivity, as for low a/ d values no A -function could be determined. Statistical analyses show no significant difference between the direct and indirect measurements at 5% level. All hydraulic conductivity values measured by the auger method are higher than those of the undisturbed soil core samples. This could be related to the presence of water passageways in the field which permit an easier movement of w water through the soils. The values confirm the suitability of the auger hole values for designing depths and spacings of drains in the heavy clayey and compact alluvial soils of Egypt. The obtained values will be used for the installation of horizontal and vertical drainage in the examined areas.