## 3 Materials and Methods
### Data  
The first step in the workflow included downloading data from the USGS GloVis data repository, which offers a global coverage of the publicly available satellite images with open access. We selected the three areas of Bumba, Basoko and Kisangani and collected the Landsat-8 OLI/TIRS imagery for the dates 2013 and 2022. The exact Landsat Product IDs are summarised in Table 1. The main characteristics of the imagery are summarised in Table 2.  
The common technical parameters for all the scenes are as follows: spacecraft ID-- Landsat 8; origin: USGS; station ID--LGN; sensor ID--OL_TIRS; processing level--L1 TP; collection number--2; collection category--T1; output format--GEOTIFF; WRS type--2; datum and ellipsoid--WGS84; data source elevation--GLS2000; GCP version--5. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Region, Year** & **Landsat Product ID** & **Landsat Scene ID** \\ \hline Basoko, 2013 & LC08\_L1 TP\_177059\_20131216\_20200912\_02\_T1 & LC81770592013350 LGN01 \\ Basoko, 2022 & LC08\_L1 TP\_177059\_2020208\_20220212\_T1 & LC81705920220391 GN00 \\ Bumba, 2013 & LC08\_L1 TP\_187058\_20131223\_20200912\_02\_T1 & LC81780582013357 LGN01 \\ Bumba, 2022 & LC08\_L1 TP\_187058\_2020130\_20220204\_02\_T1 & LC81780582022030 LGN00 \\ Kisangani, 2013 & LC08\_L1 TP\_176060\_20130413\_20200913\_02\_T1 & LC81760602013103 LGN02 \\ Kisangani, 2015 & LC08\_L1 TP\_176060\_20150113\_20200910\_02\_T1 & LC81760602015013 LGN01 \\ Kisangani, 2022 & LC08\_L1 TP\_176060\_2020217\_20220302\_02\_T1 & LC81760602022048 LGN00 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Landsat-8 OLI/TIRS Product ID and Scene ID. Figure 3: The functionality of R packages used for satellite image processing and classification in this study. Major packages include terra, raster, Rstoolbox, rgdal, rgeos, cluster, graphics, and RColorBrewer. The used images are categorised by the L1 TP Level 1 Precision Terrain (corrected), which are the DNs in a 16-bit integer format, converted to the top-of-atmosphere (TOA) spectral reflectance (Bands 1-9) or radiance (Bands 1-11) using scaling factors [97]. The L1 TP images include radiometric, geometric, and precision correction and use a digital elevation model (DEM) to correct errors caused by the local topographic relief; the accuracy of the precision/terrain-corrected product depends on the ground control points (GCPs) obtained from the GLS2000 dataset and the resolution of the DEM. Thus, the geometric accuracy of the L1 TP Landsat images is valiadated using the ground control points (GCP), which are derived from the GLS2000 library. These data are used for computing the RMSE of the geometric residuals on the terrain-corrected images [97]. An additional image for 2015 was selected for Kisangani due to the higher cloud coverage in 2013. The geographic map in Figure 1 has been plotted using the generic mapping tools (GMT) defined by scripts following the existing methodology [98; 99; 100]. The study area encompasses the middle Congo river basin with the three specific towns of Bumba, Basoko, and Ksangani, located in consecutive order southwards. The collected data were inspected for metadata using R Listing 1.