| Abstract Submission No. | ABS-4.1-0229 |
| Title of Abstract | A Review of regional and international meteorological networks offering soil moisture sensors and a review of the analytical methodology. |
| Authors | Keith Bellingham* |
| Organisation | Stevens Water Monitoring Inc. |
| Address | 12067 NE Glenn Widing Dr #106 Portland, Oregon, India Pincode: 97220 E-mail: ageorge@stevenswater.com |
| Country | India |
| Presentation | Poster |
| Abstract | Soil moisture is a significant factor in Earth¿s hydrological cycles that influences weather, drought, climate, and water resources on land and in water bodies. However, throughout most of the 20th century, soil moisture received less attention and was not included in many hydrological studies. Then, in 1978, J. W. Deardorff with the United States¿ National Center for Atmospheric Research started to demonstrate the relationship between soil moisture and meteorologic conditions and, two years later, in 1980 G. C. Topp at the University of Toronto developed the Topp Equation - the first empirical calibration for soil moisture using Time Domain Reflectometry. Additionally, that same year, M. T. van Genuchten published the van Genuchten Equation, which established a numerical relationship between soil moisture and unsaturated hydrologic head. Starting in the 1990s, the United States Department of Agriculture began using impedance-based soil moisture sensor technology to equip SNOTEL sites for watershed scale water supply forecasts. Since then, numerous large-scale regional meteorological networks have emerged worldwide, incorporating soil moisture sensors, often referred to as ¿Mesonets¿. Currently in the United States there are about 27 major regional meteorological networks that have soil moisture sensors. There are a total of 1,880 stations with over 7,300 soil moisture depths between the 27 networks. 60 to 70 percent of the 7,300 soil sensors are a coaxial impedance reflectometry technology called the HydraProbe manufactured by Stevens Water Monitoring Systems, Inc. based in Portland, Oregon USA. |
| Keywords | Soil Moisture, Hydrology, Mesonets, SNOTEL, Hydraprobe, Stevens Water Monitoring, Topp Equation, Van Genuchten Equation |