Potentials and limitations of optical and SAR satellite imagery for grassland monitoring

Conference paper

This study served as a starting point to classify converted grassland areas and to determine the ecological value of grasslands. Optical satellite data and SAR data were combined to derive plant parameters and to estimate cutting frequency and cutting dates of grassland sites. Sample points of meadows that had been investigated in the course of the Bavarian grassland monitoring served as ground truth data.

The radiative transfer model SLC (Soil-Leaf-Canopy) was used to derive plant parameters such as leaf area and chlorophyll content of the vegetation from optical remote sensing data for the known sample locations.

Time series of these plant parameters were used to classify meadows that had potentially been converted into other land use classes. The classification shall assist the Bavarian State Office in adapting future monitoring strategies.

Additionally, the analysis of LAI time-series gave an indication of the number of cuts and therefore usage intensity of the investigated samples. The study was completed by observing changes in SAR backscatter values of the investigated sites and comparing the observed patterns to the leaf area time-series of the optical remote sensing data.