Vandens lygio vertinimas upėse naudojant palydovinius Copernicus duomenis /

Rivers and lakes are important freshwater resources, providing drinking water for many people around the world and are essential for all life forms. Monitoring water parameters in rivers, lakes and other water bodies is difficult due to high costs and low accessibility of sites. Cost-effective remote sensing is designed to predict and monitor water quality in both small and large and logistically challenging areas. The use of satellite data allows monitoring of a large number of rivers and over large areas. The aim of this work is to assess the potential of Copernicus Land Monitoring Service data to determine the water levels in Lithuanian rivers. This work analyzes satellite altimetry measurements recorded over the period of the years of 2016 to 2023 in Nemunas river basin in Lithuania. The study used altimetry sensor data from different missions - Sentinel-3A and B, Sentinel-6A, Jason-2/3, and in situ data, which were used to create data pairs (26 pairs) that meet the requirements of the study. In order to check the agreement between measurement data pairs, Correlation coefficient (R) average R for all pairs of stations = 0.75) and RMSE (average RMSE for all pairs of stations = 0.52) were calculated, the results allowed to assess the accuracy of the satellite altimetry measurements in different river widths and missions. The results showed that satellite altimetry measurements are more accurate in wider rivers (in rivers up to 100 m R = 0.48, 100–200 m R = 0.77 and wider than 200 m R = 0.78). To better assess the accuracy of the results, graphs comparing satellite altimetry data with in situ data were created to provide a better understanding of the agreement between the data. The paper also analyzes the possibility of satellite altimetry to capture floods. The results showed that it is difficult for altimeters to capture the onset of floods due to the orbital timing of the satellite passes. However, the satellites are capable of detecting the timing of floods, which is a new way that is yet to be used for monitoring water level fluctuations. Overall, the results lead to conclusion that Sentinel-3A and B, Jason 2/3 and Sentinel-6A missions provide altimeter data that can be and used for monitoring Lithuanian rivers.

Grantor dc:publisher

Institutional Repository of Vilnius University

Year dc:date

2024

Author dc:creator

• Tamašauskas, Rokas,

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

lit

Repository record dc:identifier

https://repository.vu.lt/VU:ELABAETD210643307&prefLang=en_US

OAI identifier oai:identifier

oai:vu.lt:elaba:210643307