Determining water level fluctuations in small-area lakes using satellite radar data

Abstract

The research objective was to determine whether and to what extent SAR data can be used to determine changes in the water level in small glacial lakes (with an area of ~1 km2). The research object was Lake Biskupińskie – a small post-glacial lake in central Poland. As part of the research, a methodology for determining water level in small-area lakes based on radar data was developed, the potential for determining lake water levels using high- and medium-resolution SAR data was determined, and the results were verified against field measurements. The analyses employed data from two satellites, TerraSAR-X and Sentinel-1. The research confirmed the effectiveness of using SAR data to determine water-level fluctuations in small glacial lakes. The proposed methodology for working with data from the Sentinel-1 satellite allows for accurate estimation of WLF based on the results of interferometric analyses. Comparative analysis of the radar data results (lake surface) and field measurements (water level) were fully consistent with the data from TerraSAR-X and partially consistent with the data from Sentinel-1. The methodology of radar data analysis to determine WLF proposed in the paper has major research and applied potential, especially in the reconstruction of historical lake water levels.