Ground-based soil-moisture measurement was an integral part of the Southern Great Plains 1997 (SGP97) Hydrology Experiment. Near-surface and profile measurements were made using a variety of techniques and instrumentation. These data must be inter-compared and quality assured to maximize their value in meeting the Experiment's objectives.
This study draws on three independent sources of SGP-97 soil moisture information: (1) heat dissipation sensors for measuring soil matric potential, installed at four depths at certain Oklahoma Mesonet sites; (2) surface and profile measurements of gravimetric water content; and (3) profile measurements of volumetric water content using time domain reflectometry (TDR). The paper focuses on those cases where gravimetric and/or TDR measurements of soil moisture were made in close proximity to Mesonet soil moisture sites. The data are interpreted and compared, and conclusions drawn with respect to the calibration, validity, and utility of each data source in the SGP97 context. The results are also of value in evaluating the performance of Mesonet's statewide soil moisture network.