Novel, Ultralight Platform for Mapping Water Quality Parameters in Low-Order Streams

Advances in environmental sensorshave resulted in new approachesfor sampling streams and rivers from moving platforms including drifters,drones, and boats. Despite the range of sampling approaches, thereremains an unoccupied niche for a platform large enough to supporta scientist and instrument payload while also being small enough forsmall streams. In this paper, we describe the development of a samplingplatform deployed from an inflatable raft (Packraft) intended foruse in low-order systems. In addition to environmental sensors anda GPS unit, we also included the capability for automated collectionof discrete water samples. We tested this platform by tracking nitrate(NO3 (-)) with an optical sensor and dissolvedreactive phosphorus (DRP) in discrete water samples collected fromagricultural watersheds in Minnesota, USA. Data collected from thePackraft captured the effects of land use, subsurface tile drainage,and the presence of lakes and wetlands on NO3 (-) concentration in the stream channel. Repeated sampling campaignsrevealed temporal shifts in NO3 (-) andDRP patterns. Spatially resolved observations in low-order streamsthat were previously inaccessible can provide new insights into thebiogeochemistry of managed landscapes and may be helpful in guidingconservation efforts more effectively. Anultralight inflatable raft (Packraft) is combined withmonitoring equipment to serve as a suitable platform for collectingspatially referenced water quality data in small agricultural streams.