Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 28, 2004
Publication Date: December 20, 2004
Citation: Nichols, M.H. 2004. A radio frequency identification system for monitoring coarse sediment particle displacement. Applied Engineering in Agriculture Vol.20(6): 783-787. Interpretive Summary: Sediment is a primary pollutant on western rangelands. Much of the sediment is conveyed through normally dry channels during the summer monsoon season. The sediment load is made up of a range of particle sizes from fine silt and clay to large rocks and boulders. Sediment that is carried in transport is often deposited downchannel. Understanding how and where the coarse particles move is important for developing models for predicting the downstream impacts of sediment loads. An experiment was set up on the Walnut Gulch Experimental Watershed to track racquetball sized particle during runoff. A radio frequency identification system that is operated like a metal detector was designed for finding the particles after a runoff event. The system is also used to read an encoded data string sent from a transponder within the particle so that each particle has a unique identification tag. The system was used to recover 96% of the particles searched for and will continue to be used as part of long-term sediment transport studies.
Technical Abstract: A radio frequency identification system was implemented to monitor the displacement of coarse particles following runoff in two upland, ephemeral channels on the USDA-ARS Walnut Gulch Experimental Watershed in southeastern Arizona. Commercially available radio frequency identification components including transponders, an antenna, a reader, and software were used to develop a system for locating particles under field conditions. During the 2003 field season 124 particles were located following four runoff events in two ephemeral channels. The locations of 340 particle positions were measured with a differential geopositioning system after each particle was located with the radio frequency identification system. The overall recovery rate was 96%. The passive transponder system offers the advantages of low cost, consistent results under harsh environmental conditions, and no need for a power supply in the particle. The radio frequency identification system can be used to efficiently collect data for developing sediment transport equations and improving mathematical models for simulating sediment transport under natural runoff conditions.