# Planning MAR Schemes Using Physical Models: Comparison of Laboratory and Field Experiments
## 3 Results
### Influence of Setup Settings on Comparison  
To investigate the influence of different experimental setup parameters on the results, we compared the results obtained from infiltration in different soils and under different climate conditions. The parameters used for comparison included the water content, tension, and parameters calculated from these measurements. Results from infiltration scenarios with the second soil are depicted in Figure 4. Compared to the soil discussed above, this soil was siltier. Thus, the hydraulic conductivity of soil 2 was reduced by a magnitude of 10 and led to the minimum and, especially, the maximum tension values ranking up to 2 kPa higher than the values for soil 1. It further caused a drying phase with a much clearer difference in tension behavior between the upper and the lower layer shown for all setups and scenarios. Tension in the lower layer was more than 1 kPa higher than in the upper layer, and in case of the 3-day drying phase of scenario 3, the difference became larger than 2 kPa. Figure 4: Tension measurements of laboratory experiments (tank and column) compared to field measurements in 0.3 m (UL—upper layer) and 0.7 m (LL—lower layer) depths for scenarios 3 and 4. Figure 3: Calculation of mean and minimum tension values during the wet phase and maximum tension values during the dry phase for every cycle of scenario 2. Differences that have been attributed to setup modifications are also evident. Same as for soil 1, the FIU and tank values during the wetting phase were relatively close, ranking between 1.7-2 kPa. The column values were always more than 1 kPa lower during this phase, confirming the above-mentioned hypothesis. Same as above, for soil 2 the column and tank drying behavior was very similar, with a rapid drying phase in the LL followed by an almost constant tension behavior. However, column values ranked only slightly lower than tank values. Differences between laboratory and FIU values became even stronger during this phase than the ones shown in Figure 2, with tension values up to 2 kPa lower in the FIU. While air temperature and humidity were kept constant for the laboratory experiments, the FIU was influenced by the local climate. To assess the influence of the climate on water flow in the unsaturated zone, the experiments were repeated for three different climate scenarios (compare Table 1, column 4-6). Results show that the difference between measurements of the FIU and tank was much larger than the difference of FIU water content measurements under different climates (Figure 5). In the deeper layer, the influence of climate was only visible during the wet phase, where the water content measured under the cold climate was slightly higher than the water content of the experiments conducted under the other climates. The difference to the tank measurements was much more distinct, where during the wet phase water content dropped to 22%, compared to 28% in the FIU. In the lower layer, the dry phase showed no difference between field climates and the tank values are relatively close. However, draining remained relatively constant in the tank after an initial drop, whereas in the FIU a decreased but continuing draining could be observed. In the upper layer, the influence of climate on the water content became more visible, with the drying phase showing 3% higher water content for the warm climate. Again, the difference to tank values was much more distinct with water content values during the wet phase, dropping to 22% after initially being as high as the FIU values. The largest difference could be observed during the drying phase, where values were more than 5% below those of the FIU. The influence of the experimental setup itself can be well observed, when assessing the arrival times of the wetting front at 0.7 m depth (Figure 6), which was calculated as duration from infiltration start to the start of tension decrease.