A NEW EQUATION FOR SIMULATING SOIL WATER CHARACTERISTIC CURVE | ||||
| Journal of Soil Sciences and Agricultural Engineering | ||||
| Article 4, Volume 32, Issue 10, October 2007, Page 8777-8794 PDF (966.21 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jssae.2007.201551 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| B.M. El-Garhy1; W.M. Omran2 | ||||
| 1Civil Engineering Dept. Fac. of Eng. Minofiya University. | ||||
| 2Soil science Dept. Fac. of Agric. Minofiya University. | ||||
| Abstract | ||||
| Several mathematical equations have been proposed to simulate soil water characteristic curve (SWCC). All the equations show reasonable fit with measured data through a specified range of suction and in a specific soil texture, but this is not the case for suction less than air entry and close to residual water content. The present work is aiming to introduce an applicable equation can simulate the SWCC and achieve good fit to measured data through the entire range of soil suction for variety of soil textures. Following different sequence than that has been followed by many authors who focus on the physical meaning of the equation parameters, we attempted to create a new equation depending on the features of the SWCC. This idea helped in avoiding the difficulty of mathematical processes and non-accuracy of graphical solutions and also not include any soil properties except soil suction and water content. Such equation could be easily calculated using any non-linear fitting computer program. The performed statistical analysis and obtained fit with measured data, revealed that the proposed equation successfully simulated SWCC for entire range of suction (i.e. 0 : 106 kPa). The results also reveal that the presented equation was constantly the best equation in its fit to measured data among 16 SWCC studied equations. It could be concluded that the proposed equation is applicable accurate and flexible and can successfully employed as a predictive equation for the total SWCC. The research also suggest further studies to find out average values to different soil texture types to predict SWCC for Egyptian soils. Another needed studies are using the equation in calculating grain size distribution and hydraulic conductivity for unsaturated soils, since the equation give the common sigmoidal curve. | ||||
| Keywords | ||||
| Soil water characteristic curve; mathematical equations; nonlinear regression | ||||
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