Monitoring of Calcite Precipitation in Hardwater Lakes with Multi-Spectral Remote Sensing Archives

摘要: Calcite precipitation is a common phenomenon in calcium-rich hardwater lakes during spring and summer, but the number spatial distribution of with calcite unknown. This paper presents remote sensing based method to observe over large areas, which are an important prerequisite for systematic monitoring evaluation restoration measurements. We use globally archived satellite data retrospective assessment past multi-temporal events. The database this study consists 205 sets that comprise freely available Landsat Sentinel 2 acquired between 1998 2015 covering Northeast German Plain. automatically identified using green spectra metric BGR area, triangular area blue, red reflectance value. validation on field measurements CaCO3 concentrations at three selected lakes, Feldberger Haussee, Breiter Luzin Schmaler Luzin. classification accuracy (0.88) highest ≥0.7 mg/L. False negative results caused by choice conservative threshold. positive can be explained already increased concentrations. successfully transferred developed 21 other Germany. average duration regular 37 days. frequency reaches from single time detections up nearly every year. gaps series reduce monitoring, future image density will increase acquisitions Sentinel-2a (and 2b). Our tested transfer approach Sentinel-2 images. shows 15 24 have least one phase all events occur May September. At we illustrated influence ecological measures aiming nutrient reduction lake water precipitation. emphasizes high variance lakes: each has monitored individually, feasible series.