Lavaka volumes: Data, PyGIS code and example

Dataset and PyQGIS code for the automated determination of lavaka (gully) volumes in QGIS based on three different DEM sources: TanDEM-X, SRTM and a high-resolution UAV-SfM DEM. Lavaka volumes were determined for 699 lavaka in 6 study areas in the lake Alaotra region (Madagascar) and builds upon this earlier published dataset (doi.org). Individual lavaka volumes were determined from the difference between the current surface and a reconstructed pre-erosionsurface. This was done by developing an automated workflow in PyQGIS written in QGIS version 3.8.1 with GRASS 7.6.1. The automated PyQGIS workflow consists of 6 steps which are explained in detail in the readme file. The input data required to run the procedure is discussed in step 0. In this repository three main files can be found: the PyGis code to obtain the volumes in QGIS An example dataset containing input and output files for a test area: three lavaka and SRTM DEM An excel table containing the results of the full lavaka dataset organized in different sheets: Original volumes UAV-SfM:the presented volumes are ontained as the difference between the interpolated (spline interpolation) pre-erosion surface and the current surface for the UAV-SfM DEM Original volumes TanDEM-X: the presented volumes are ontained as the difference between the interpolated (spline interpolation) pre-erosion surface and the current surface for the TanDEM-X DEM Original volumes SRTM: the presented volumes are ontained as the difference between the interpolated (spline interpolation) pre-erosion surface and the current surface for the SRTM DEM applied A-V TanDEM-X:the presented volumes are obtained after applying the breakpoint area-volume relationship based on the TanDEM-X spline volumes to the lavaka areas of 1949, 1969 and 2010s applied A-V UAV-SfM: the presented volumes are obtained after applying the area-volume relationship based on the UAV-SfM spline volumes to the lavaka areas of 1949, 1969 and 2010s