Keywords
spaceborne earth observation, sar interferometry, coherence analysis, river dynamics, flood, floodplain structures, floodplain management, river odra
Start Date
1-7-2004 12:00 AM
Abstract
River dynamics and hydrological behaviour are strongly influenced by human activities both in the catchment areas and in the floodplains. The knowledge of recent and historical river dynamics and related morphological and structural changes on the land surface (e.g. sedimentation, accumulation, river bed movement) is essential in assessing the flood risk and the vulnerability of human resources and structures. Earth Observation (EO) systems provide data to monitor and to analyse both, the river dynamics and small surface changes. Especially, radarbased systems and interferometric data analysis are of high interest. Along selected sites in the River Odra area, we analysed the potential of radar-based EO-applications for the detection of structural changes, validated by fieldwork. It is shown that the coherence information is of great significance: On the one hand, it could be used to eliminate misclassifications of the flood extent caused by double bounce scattering, corner reflection or smooth surfaces. On the other hand the production of RGB’s type Interferometric Signatures (coherence, average, difference of tandem pairs) proofed to be a powerful tool to visualise the flood dynamics in space and time but also the morphologic structure in the floodplain. As conclusion, it is shown that the combined analysis of radar backscatter and coherence information will be very useful in the flood application domain, especially with respect to risk assessment and vulnerability mapping. In addition, the methods described will support the collection of relevant base data claimed by the EU water framework directive.
Assessing the Feasibility of Using Radar Satellite Data to Detect Flood Extent and Floodplain Structures
River dynamics and hydrological behaviour are strongly influenced by human activities both in the catchment areas and in the floodplains. The knowledge of recent and historical river dynamics and related morphological and structural changes on the land surface (e.g. sedimentation, accumulation, river bed movement) is essential in assessing the flood risk and the vulnerability of human resources and structures. Earth Observation (EO) systems provide data to monitor and to analyse both, the river dynamics and small surface changes. Especially, radarbased systems and interferometric data analysis are of high interest. Along selected sites in the River Odra area, we analysed the potential of radar-based EO-applications for the detection of structural changes, validated by fieldwork. It is shown that the coherence information is of great significance: On the one hand, it could be used to eliminate misclassifications of the flood extent caused by double bounce scattering, corner reflection or smooth surfaces. On the other hand the production of RGB’s type Interferometric Signatures (coherence, average, difference of tandem pairs) proofed to be a powerful tool to visualise the flood dynamics in space and time but also the morphologic structure in the floodplain. As conclusion, it is shown that the combined analysis of radar backscatter and coherence information will be very useful in the flood application domain, especially with respect to risk assessment and vulnerability mapping. In addition, the methods described will support the collection of relevant base data claimed by the EU water framework directive.
