The ability to dynamically measure the electrical conductivity of runoff is key to many hydrologic applications including hydraulic property characterization and solute transport quantification. In applications requiring a large number of wireless conductivity sensors, the limited availability and high cost of commercial options can make deployment prohibitive. Here, a low-cost, rugged, and precise wireless sensor network system has been developed to measure runoff electrical conductivity in the field and laboratory. The sensing module is designed around an inexpensive microcontroller generating an alternating voltage to excite the two measurement electrodes. Each microcontroller is coupled with a Radio Frequency (RF) module which sends the measured data to a data collection RF module connected to a commercial datalogger. Laboratory tests in static salt solution columns showed that changes in salt concentration of 0.01 mg/ml were detected by the devices. The system has been successfully used to trace a pulse input of salt for runoff flow velocity measurement, and is routinely used to monitor native salt detachment and transport from saline rangeland erosion plots during rainfall simulation experiments.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.