A study of a texture-based equation for estimating the saturated hydraulic conductivity of an alfisol in the sudan savannah ecological zone, Ghana

Abstract

Abstract Saturated hydraulic conductivities of Varempere series soils (plinthaqualf) located in the sudan savannah zone of Ghana were measured by the falling head method and compared with values estimated by the texture-based equation of Rawls et al. (1982). The comparisons indicated that saturated hydraulic conductivity values estimated using the texture-based equation could predict those measured within the same order of magnitude only for the coarse-textured soil. For the fine textured soils, the texture-based equation underestimated the measured values by approximately one order of magnitude. It was concluded that in modelling hydrological processes such as infiltration in coarse-textured soils, the use of the texture-based equation would be useful. However, for technical designs of irrigation and drainage systems that require more accurate information on saturated hydraulic conductivity, the use of the texture-based equation should be discouraged.