Analyses of moisture parameters and biomass of vegetation cover in southeast Moravia

Abstract

The paper describes the analyses of moisture parameters and biomass of vegetation cover. These include a relative moisture classification, a relative biomass classification, and the actual aboveground biomass estimate. All analyses were carried out by applying spectral indices and fuzzy classification for assessment. The satellite imagery from the Thematic Mapper (TM) (Landsat 5) and the Enhanced Thematic Mapper Plus (ETM+) (Landsat 7) was used as input data. Biomass indices derived from the satellite imagery were correlated with table data of average crop yields in 2007. Since the imagery used was from three periods of time (May 2001, July 2007, August 2000), it could have been assessed in terms of both time dependence and phenological phases. The monitored variables during the year were the relative moisture and vegetation biomass. The territory of interest was the Trkmanka River basin in southeast Moravia. Time dependence was obtained with the results of classifications in terms of varying phenological phases as well as dependence between the two characteristics. The data from the comparison of May and June revealed primarily their increase (a decrease occurred only on arable land), whereas those from the comparison of July and August revealed mainly their decrease. The two characteristics show almost linear mutual dependence except for some forest land. We processed map outputs showing the spectral indices used, changes in relative moisture and relative biomass, the actual biomass estimate, and a deviation from a linear dependence of the two characteristics under examination. The selected indices were processed into Geoscientific Model Development (GMD) – models that can be repeatedly run in Model Maker in Earth Resources Data Analysis System (ERDAS) IMAGINE. Together with the models of spectral indices, these were optimized for the sensor TM and ETM+.