Using Landsat 8 Images for The Wetland Water Stress Calculation: Upper Biebrza Case Study

This study is focused on detecting water stress on natural wetland ecosystems. In the Upper Biebrza Basin (NE Poland), on the meteorological tower, continuous measurements of plant surface temperature and basic meteorological parameters (air temperature and humidity) were conducted. Based on this measurements Crop Water Stress Index (CWSI) was calculated. Also Landsat 8 thermal images were used for similar calculation. Firstly, correlation of Landsat 8 based and tower based CWSI was evaluated. The high agreement of values regards this two sources was obtained (R2 = 0.99, p-value < 0.01, slope of adjusted model is equal to 0.989 and its intercept is equal to 0.0003). Secondly, the Landsat based CWSI was calculated for all wetland ecosystems in the Upper Biebrza Basin for selected images from the period of 2014-2016 years. Results show positive verification of satellite images as a source for CWSI calculation for natural wetland ecosystem, additionally, water stress was indicated frequently during analyzed years.