Evaluation of ERS data for biomass estimation of meadows

Abstract:

The knowledge about amount of biomass is necessary to determine the impact of the landcover on the hydrological cycles due to the fact that different plants show significant differences in evapotranspiration. The study area for this work is the catchment of the Ammer River, which covers about 1200 km2 in the Bavarian Alpine Foreland. Since grassland in various forms is the dominating agriculture land use in the testsite, investigations were made on the utilisation of radar data for the determination of the temporal development of grassland biomass. ERS-1 / ERS-2 data were used for this task. For verification, data from several meadows, which were investigated from 1992 to 1996 are used. The plant parameters height, wet and dry biomass were measured on a weekly base during the vegetation period. Statistical approaches were applied to investigate whether one of the plant parameters can be correlated to the backscatter signal. It is shown that there is a correlation between the signal intensity and the vegetation height of meadows. Due to the fact that the plant height correlates with the biomass, the grassland biomass can be estimated in the testsite. Furthermore, the data of the tandem mission 1995/1996 were used to investigate the possibility of the detection of temporal biomass changes. For this approach interferometric information were used for coherence analyses. To validate the results the coherence information is compared to a large set of ground truth data which were collected during three intensive field campaigns.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry