Assessment of different methods for Evapotranspiration and Soil Moisture for various land use areas across Poland

The main goal of the study w as to determine the evapotranspiration and soil moisture for
different ecosystems as grasslands, grassland wetlands and agriculture fields in Pokand. There is a
significant potential to estimate water usage by plants and to illustrate how they return water to
the atmosphere by applying the soil vegetation temperature measured now days by satellites.
The proper assessment of evapotranspiration and soil moisture content are essential in food
security research, land management, climate change observations and hydrological modelling
Collected ground data covers grasslands areas (intensive and extensive management), at the
JECAM Joint Experiment for Crop Assessment and Monitoring. Ground data collection
included measurements of soil moisture, biomass samples and agrometeorological parameters.
It was possible to collect the data from ECOSTRESS (temperature and latent heat flux LE )
for JECAM fields for different dates during vegetation growth and few acquisitions of
ECOSTRESS  for the grasslands for the whole NUTS2 where the JECAM area exists. For the
grassland of wetlands in the North of Poland there were only two ECOSTRES S acquisition s.
At the same time of ECOSTRES S acquisition the data from Terra MODIS, Sentinel 2 and
Sentinel 3 were collected in order to calculate the vegetation indices and get the surface
temperature. At the JECAM field we conducted the measurements of meteorological
parameters. At the grass area of wetlands we installed the Eddy Covariance tower for flux
measurements and twenty soil moisture sondes with permanent measurements. The LE values
obtained from ECOSTRESS data were compared to the latent heat (calculated as the component
of energy budget). Surface temperature derived from thermal channels of Terra MODIS and
Sentinel 3 in conjunction with meteorological data have been used for calculation of LE as a
residual of the of the simplified energy budget equation (Dabrowska Zielinska et al., 2022 ). At
the same time different vegetation parameters were calculated from Sentinel’s index NDVI to
establish the correlation between the vegetation phase of development soil moisture values and
evapotranspiration conditions. Climate conditions influence evapotranspiration through
available soil moisture. Vegetation influence evapotranspiration through its biomass, plant
height and vegetation response to soil moisture. Created models applying measured LE by
ECOSTRESS and vegetation parameters allowed to transfer the water demand by plants to
other areas. For understanding the mechanistic responses of ecosystem processes to
environmental change it is important to examine evapotranspiration its annual change for
different ecosystems with the available data for vali dation. The study used artificial intelligence
methods including machine learning techniques for modelling evapotranspiration
Dąbrowska - Zielińska K., Misiura K., Malińska A., Gurdak R., Grzybowski P., Bartold M., Kluczek M., 2022,
Spatiotemporal estimation of gross primary production for terrestrial wetlands using satellite and field data,
Remote Sens. Appl.: Soc. Environ. doi:10.1016/j.rsase.2022.100786
The study has been done for the project: GrasSat "Tools for information to farmers on grasslands yields under
stressed conditions to support management practices" NOR/POLNOR/GrasSAT/0031/2019  financed by
Narodowe Centrum Badań i Rozwoju (NCBIR) Norwegian Funds