title: Heated distributed temperature sensing for field scale soil moisture monitoring.
abstract: Characterizing both spatial and temporal soil moisture (θ) dynamics at site scales is difficult with existing technologies. To address this shortcoming, we developed a distributed soil moisture sensing system that employs a distributed temperature sensing system to monitor thermal response at 2 m intervals along the length of a buried cable which is subjected to heat pulses. The cable temperature response to heating, which is strongly dependent on soil moisture, was empirically related to colocated, dielectric-based θ measurements at three locations. Spatially distributed, and temporally continuous estimates of θ were obtained in dry conditions (θ≤ 0.31) using this technology (root mean square error [RMSE] = 0.016), but insensitivity of the instrument response curve adversely affected accuracy under wet conditions (RMSE = 0.050).
authors.affiliation: Department of Civil and Environmental Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706.
authors.forename: Arlen M
authors.initials: AM
authors.lastname: Striegl
authors.forename: Steven P
authors.initials: SP
authors.lastname: Loheide
mesh_terms: D002138:Calibration; D004784:Environmental Monitoring / Q000379:methods*; D006358:Hot Temperature; D012987:Soil; D014867:Water / Q000032:analysis*
chemical_list: D012987:Soil; D014867:Water