PRINCIPLE AND APPLICABILITY OF COSMIC-RAY NEUTRON METHOD FOR MEASURING SOIL MOISTURE

Regional soil moisture monitoring has always been a difficult point in many researches. The traditional point measurement and the large scale remote sensing monitoring are always unable to obtain information of medium and small scale regional soil moisture. As a new type of mesoscale soil moisture condition monitoring method, the cosmic ray neutron method can obtain the soil moisture information within 300 m radius of the source region, which covers the shortage of the point measuring method and remote sensing method. This study utilized cosmic ray neutron instrument (CRS) to constantly monitor soil moisture, and conducted the applicability research of cosmic ray neutron method in soil moisture monitoring. Results show high consistency of CRS and time domain reflectometer (TDR) measurements, the fitting degree is 0.847, the root mean square error is 0.020 kg/kg. Also, CRS is sensitive to precipitation, it can clearly show the increase of soil moisture under different conditions, while the sensitivity of TDR is relatively poor. This research can provide a reference for dynamic change monitoring of regional mesoscale soil moisture.