# Unsaturated Hydraulic Conductivity in Composite Porous Media
## 3 Results and Discussion
Because the apparatus is vertically oriented, gravity produces flow drag effects \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Material**} & \multirow{2}{*}{**Sample**} & \multicolumn{2}{c}{**Initial Height (cm)**} & \multicolumn{2}{c}{**Final Height (cm)**} & \multirow{2}{*}{\(k_{s}\) (cm/s)**} & \multirow{2}{*}{**Std. Dev.**} \\ \hline \multirow{4}{*}{Guamo Sand + Diatomites} & 100\% & & & 0.02416 & 0.00481 \\  & 5–95\% & & & 0.02390 & 0.00119 \\  & 10–90\% & & 160 & 50 & 0.01648 & 0.00062 \\  & 20–80\% & & & 0.00916 & 0.00011 \\  & 40–60\% & & & 0.00086 & 0.00005 \\ \hline \multirow{4}{*}{Guamo Sand + Fe\({}_{2}\)O\({}_{3}\)} & 100\% & & & 0.02416 & 0.00481 \\  & 5–95\% & & & 0.02192 & 0.00105 \\  & 10–90\% & 160 & 50 & 0.01276 & 0.00099 \\  & 20–80\% & & & 0.00088 & 0.00006 \\  & 40–60\% & & & 0.00009 & 0.00002 \\ \hline \multirow{4}{*}{Guamo Sand + CaCO\({}_{3}\)} & 100\% & & & 0.02416 & 0.00481 \\  & 5–95\% & & & 0.01599 & 0.00095 \\  & 10–90\% & 160 & 50 & 0.01370 & 0.00092 \\  & 20–80\% & & & 0.00043 & 0.00043 \\  & 40–60\% & & & 0.00006 & 0.000003 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Saturated permeability results by KSAT and conventional permeameter. through the granular cell, especially at low liquid levels. At the lowest point of the sample within the permeameter, the flow through the sample interface and outlet channel affects the piezometric measurement. However, additional pressure breaks are caused by changes in the test permeameter cross-section in the outlet pipe and the exhaust valve. Constant and variable head patency test measurements were verified in this study using the automated KSAT control method. The dual-mode tester is ideal for evaluating \(k_{\mathrm{s}}\) results simultaneously in porous media, as it allows constant testing immediately after the variable head tests have been performed without the need to remove or reposition the sample. The constant and variable load results for each of the materials tested strongly coincide with the evaluation obtained in the conventional permeameter. In separate constant and variable load tests for hydraulic gradients from 160 to 50 mm, the reproducibility of the data in both methods was evaluated using analytical techniques by the arithmetic mean. This is because a variable probability distribution representing some characteristic of a population is completely defined when its parameters are known. When the opposite occurs, estimating them based on the sample data is necessary to make inferences in the population. As it is a single variable (\(k_{\mathrm{s}}\)), there is a wide confidence interval, and an excellent way to measure this type of data that resembles a normal distribution is the mean since it adequately represents the result of the repetitions of the tests [67]. The results obtained from the MDI for the direct case in the five materials were compiled and analyzed graphically to understand the accumulated infiltration in unsaturated media better. For each test, the soil's initial and final water content immediately below the disk was recorded, and infiltration ranges corresponding to five suction levels from 1 to 5 cm were applied to all remodeled specimens of compacted soil. The details of the \(k_{u}\) values are descriptively expressed in Figure 6. The experimental data analysis indicates a corresponding relationship between the \(k_{u}\) parameter and suction at high ranges. The null suction phases for each material in each percentage combination correspond to the average value of \(k_{u}\) in the saturated state, that is, \(k_{\mathrm{s}}\) reached by the MDI system. The trend of the \(k_{u}\) results indicates significant losses in the infiltration capacity of each material as the suction reaches values close to 5 cm. \(k_{u}\) was estimated using Equation (2), and the values were obtained from Figure 5. The values of \(A\) for each soil were obtained from Equations (3) and (4).