Lawrence Berkeley National Laboratory

To facilitate investigations of moisture dynamics in unsaturated soil, we have developed a technique to qualitatively monitor patterns of saturation changes. Field results suggest that this device, the sensor array system (SAS), is suitable for determining changes in relative wetness along vertical soil profiles. The performance of these probes was compared with that of the time domain reflectometry (TDR) technique under controlled and field conditions. Measurements from both techniques suggest that by obtaining data at high spatial and temporal resolution, the SAS technique was effective in determining patterns of saturation changes along a soil profile. In addition, hardware used in the SAS technique was significantly cheaper than the TDR system, and the sensor arrays were much easier to install along a soil profile.