Object Based Thermokarst Lake Change Mapping as Part of the Esa Data User Element (due) Permafrost

This study presents an approach to quantify thermokarst lake change and lake object structure change in spatial very high resolution remote sensing data as part of ESAs "Data User Element Permafrost". Lake Center points are used and multi temporal data is radiometrically normalized using a water mean rationing. A set of specific lake object characteristics (object shape, direction, lake object neighborhood structure and lake density) are parameterized in high resolution Rapideye data and in scanned pan-chromatic films from 1975 (Hexagon). Emphasis is on mapping of structural changes of thermokarst thaw lakes and changes of adjacent lake object properties. For this purpose specific relational neighborhood metrics are developed that quantify structural properties of the thermokarst lake areas and attributed changes. The classification is performed pan arctic on multiple test sites in Siberia, Alaska and Canada. The presented methodological approach provides a robust and transferrable concept for large scale change mapping and is important to quantify changes under potential permafrost degradation conditions. This work is part of the "Data User Element Permafrost" and is a contribution to an observation strategy for permafrost degradation. * Corresponding author.