Low-Cost Stand-Alone System for Real-Time Hydrological Monitoring

Water resource managers and scientists have recognized the need for data at spatial and temporal resolutions relevant to the hydrological cycle. The dearth of hydrological data sets has been noted as a critical barrier to developing effective water resource management strategies. Limited funding has been noted as a major contributing factor to the limited establishment of sustainable environmental monitoring networks to capture these data sets. To address these concerns, an inexpensive real-time hydrological monitoring station (RTHS) was designed to collect data with similar performance to existing commercially available sensors. The RTHS was built with both commercially available and custom-engineered components, using enabling technology to reduce capital and operations and maintenance costs. The RTHS incorporated a modular design for easy integration of multiple sensors and implementation of upgrades with less expensive and more reliable components as emerging technologies become available. Inexpensive stage height, water temperature, and all-season precipitation sensors were designed, fabricated, and tested in house. Integration of components into a comprehensive hydrological monitoring system required custom hardware designs and software routines. Controlled laboratory and field evaluations with a colocated research-grade sensor indicated that the designed precipitation gauge provides a low-cost alternative with comparable performance to commercially available off-the-shelf sensors. The designed stage height sensor performed well in laboratory evaluations and interobservatory comparisons at independently operated stations in the Hudson River watershed as demonstrated by strong correlations (R-2=0.99, root mean square discrepancy=1.4-3.2cm) between stage height data sets.