Demonstrating the Potential of Low-Cost GNSS Receiver for tidal monitoring, storms, and flood detecting

surges seriously threaten coastal communities. These events result in
flooding, property damage, loss of life, and long-term economic and
social impacts. Therefore, monitoring and detecting extreme
hydrological events significantly affect coastal areas in disaster
response efforts. However, the cost of installing and maintaining
these stations can be a significant challenge for developing countries.
The objective of this study is to use a low-cost GNSS receiver to
monitor tides and detect extreme coastal hydrological phenomena by
analyzing changes in water level, using analysis of the signal-to-noise
ratio (SNR) data. Data used in this study were collected from a GNSS
station located in the Tam Giang Lagoon area, Thua Thien Hue,
Vietnam, from September to October 2022. The water level based on
GNSS-R is compared with the sensor's measured water level, with
the Pearson correlation coefficient reaching 0.96 and RMSE of
0.08m. Continuous Wavelet Transform analysis demonstrated the
relationship between water levels and extreme hydrological events.
The results show that distinct signatures in the data correspond to the
Noru typhoon from September 27-29, 2022, and the inundation from
October 14-19, 2022, in Thua Thien Hue. This information is the
basis for forecasting and early warning of extreme events and
informing disaster response and management efforts.