NWDTW 2024

As part of NGWOS efforts in the Delaware River Basin, a soil moisture sensing testbed was developed at a continuous records observation well, DE 723. Both proximal and in-situ sensors were installed utilizing both novel and traditional technologies. Likely the precursor to a soil moisture sensing techniques and methods (T&M), practices are being developed for calibration, installation, verification, and analysis. Over 100 time-series are being maintained and reviewed using AQ Time-Series. Beyond soil moisture content other time-series include meteorological parameters (i.e. solar flux, precipitation, wind speed, etc), cosmic ray neutron counts, and soil temperature. Discrete measurements used for verifying in-situ and proximal soil moisture sensors are also being made and include soil core grab samples, downhole nuclear magnetic resonance logs, and handheld soil moisture "check measurements". These efforts are advancing the USGS's ability to quantify water being stored in the soil zone, while also characterizing an underrepresented phase of the water cycle. Future work regarding computation of infiltration and recharge rates, prediction of streamflow responses, and quantification of drought conditions will all benefit from long-term soil moisture records established by the USGS.