61a46ef80f63449397c9825676f3cc5a English 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646 dataset NERC EDS Centre for Environmental Data Analysis 01235446432 RAL Space STFC Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX United Kingdom support@ceda.ac.uk pointOfContact 2026-11-12T16:33:23 UK GEMINI 2.3 WGS 84 Land-cover classifications and chainage-level vegetation metrics for islands of the middle Congo River derived from Sentinel-2 imagery for 2020, 2024 and 2025 2026-11-06T12:02:59 publication 2026-11-06T12:02:59 creation https://catalogue.ceda.ac.uk/uuid/61a46ef80f63449397c9825676f3cc5a 61a46ef80f63449397c9825676f3cc5a NERC EDS Centre for Environmental Data Analysis 10.5285/61a46ef80f63449397c9825676f3cc5a doi Land-cover classifications of vegetated islands along a ~400 km section of the middle Congo River, derived from cloud-free Sentinel-2 Level-2A Surface Reflectance Harmonized imagery for the dry seasons of 2020 (pre-drought), 2024 (drought) and 2025 (post-drought). The dataset accompanies dataset accompanies Steadman et al. (in submission), "Vegetation Loss and Response to Hydrological Drought on the Islands of the Congo River." The deposit consists of three classified raster maps (GeoTIFF, 10 m resolution) and one tabular dataset (CSV): - 2020_Landcover.tif, 2024_Landcover.tif, 2025_Landcover.tif: two-class supervised land-cover classifications based on a Random Forest classifier (500 trees) trained on Sentinel-2 bands B2, B3, B4, B8 and B11. Class codes: 1 = vegetated, 2 = non-vegetated. - chainage_vegetation_metrics.csv: per-chainage summary table, with one row per 10 km chainage interval (260-640 km along the Congo River centreline upstream from Kinshasa, after Carr et al., 2019). Columns include percentage vegetated cover for each year, June-August 2024 mean precipitation (mm, from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS)) and canopy-height composition (proportion of <1 m, 1-10 m, and >10 m vegetation derived from the ETH Global Sentinel-2 10 m Canopy Height dataset, 2020). The study area covers a ~400 km corridor of the middle Congo River from just downstream of Mbandaka to a few kilometres upstream of Mpouya, spanning the border region between the Democratic Republic of the Congo and the Republic of the Congo. The corridor contains approximately 800 islands. Sentinel-2 imagery was mosaicked across MGRS tiles 33MXT, 33MXU, 33MYU, 33MYV and 33MZV. Dry-season composites were generated from images acquired on 16 June, 1 July, 31 July and 8 August 2020; 20 June, 10 July, 25 July and 8 August 2024; and 13 May and 10 June 2025. The chainage CSV summarises conditions for these three years and additionally includes June-August 2024 cumulative precipitation derived from CHIRPS daily data. Sentinel-2 Level-2A Surface Reflectance Harmonized imagery was accessed via Google Earth Engine. Cloud, cloud-shadow, cirrus and saturated pixels were masked using the Scene Classification Layer (SCL) with a 1-2 pixel buffer. Annual median composites were classified with a Random Forest model (500 trees, 70/30 train-test split) trained on manually digitised polygons of the four land-cover classes, using high-resolution historical imagery from Google Earth Pro and Bing Aerial Imagery as references. A majority filter was applied to smooth isolated misclassified pixels. Per-chainage metrics were derived in ArcGIS Pro using the Tabulate Area tool, with 10 km chainage polygons intersecting the basin-scale Congo River centreline (Carr et al., 2019) as zones. Percentage vegetated cover was computed as the vegetated area divided by the sum of vegetated and non-vegetated areas (water and sand classes were masked from the analysis). The classifications and chainage metrics were produced to characterise the spatial extent and structural pattern of vegetation loss across Congo River islands during the extreme 2024 hydrological drought, and to test the hypothesis that vegetation loss is jointly controlled by hydroclimatic exposure (rainfall gradient) and vegetation structure. Steadman, Janae Unavailable author Unavailable author Trigg, Mark A. Unavailable author Unavailable author Dargie, Greta C. Unavailable author Unavailable author Smith, Mark W. Unavailable author Unavailable author Tshimanga, Raphael Unavailable author Unavailable author O'Hanlon, Paul Unavailable author Unavailable author Carr, Andrew B. Unavailable author Unavailable author Bola, Gode Unavailable author Unavailable author NERC EDS Centre for Environmental Data Analysis custodian 01235446432 RAL Space STFC Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX United Kingdom support@ceda.ac.uk custodian NERC EDS Centre for Environmental Data Analysis distributor 01235446432 RAL Space STFC Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX United Kingdom support@ceda.ac.uk distributor Trigg, Mark A. Unavailable principal_investigator Unavailable principalInvestigator NERC EDS Centre for Environmental Data Analysis point_of_contact 01235446432 RAL Space STFC Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX United Kingdom support@ceda.ac.uk pointOfContact NERC EDS Centre for Environmental Data Analysis publisher 01235446432 RAL Space STFC Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX United Kingdom support@ceda.ac.uk publisher unknown dataset Land Cover Congo Sentinel Sentinel 2 orthoimagery theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication otherRestrictions Public data: access to these data is available to both registered and non-registered users. otherRestrictions Under the following licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/, appropriate use of these data may fall under any and attribution required use. This message is intended as guidance, always read the full licence. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. grid English imageryBaseMapsEarthCover 16.118 18.213 -2.627 0.0 2020-06-16T00:00:00 2025-06-10T23:59:59 These data are given in GeoTIFF and CSV format. NERC EDS Centre for Environmental Data Analysis Data Center Contact 01235446432 RAL Space STFC Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX United Kingdom support@ceda.ac.uk distributor https://catalogue.ceda.ac.uk/uuid/61a46ef80f63449397c9825676f3cc5a CEDA Data Catalogue Page Detail and access information for the resource information http://data.ceda.ac.uk/neodc/deposited2026/Congo_Islands_Analysis/ DOWNLOAD Download Data download https://doi.org/10.1038/sdata.2015.66 Funk, C. et al. (2015) The climate hazards infrared precipitation with stations - a new environmental record for monitoring extremes. Scientific Data 2, 150066. (CHIRPS dataset.) No further details. information https://doi.org/10.1038/s41559-023-02206-6 Lang, N., Jetz, W., Schindler, K. and Wegner, J. D. (2023) A high-resolution canopy height model of the Earth. Nature Ecology and Evolution 7, 1778-1789. (ETH Global Sentinel-2 10 m Canopy Height dataset.) No further details. information https://doi.org/10.1029/2019GL083720 Carr, A. B., Trigg, M. A., Tshimanga, R. M., Borman, D. J. and Smith, M. W. (2019) Greater Water Surface Variability Revealed by New Congo River Field Data Implications for Satellite Altimetry Measurements of Large Rivers. Geophysical Research Letters 46(14), 8093-8101. (Source of the Congo River centreline used for chainage definition.) No further details. information https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S2_SR_HARMONIZED Copernicus Sentinel-2 MSI Level-2A Surface Reflectance (Harmonized). European Space Agency / Copernicus. No further details. information dataset Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 Sentinel-2 Level-2A Surface Reflectance Harmonized scenes (COPERNICUS/S2_SR_HARMONIZED) were acquired via Google Earth Engine, filtered by cloud cover and date for the dry season of each target year, and mosaicked across MGRS tiles 33MXT, 33MXU, 33MYU, 33MYV and 33MZV. Cloud, shadow, cirrus and saturated pixels were masked using the Scene Classification Layer with a 1-2 pixel buffer, and annual dry-season median composites were derived. A Random Forest classifier (500 trees) was trained on manually digitised training polygons for four land-cover classes (vegetated, non-vegetated, water, sand) using bands B2, B3, B4, B8 and B11, with a 70/30 train-test split. Water and sand were then masked from the classification. Resulting rasters were aligned to a common 10 m grid, smoothed with a majority filter and exported as GeoTIFFs. Chainage-level metrics were generated in ArcGIS Pro using the Tabulate Area tool with 10 km chainage polygons (derived from the basin-scale Congo River centreline of Carr et al., 2019) as zones, applied to the classified rasters and the reclassified ETH Global Sentinel-2 10 m Canopy Height dataset (Lang et al., 2023). Per-chainage June-August 2024 rainfall was derived from CHIRPS daily precipitation aggregated to JJA totals and reduced over each chainage polygon. Data were produced by the project team and supplied for archiving at the Centre for Environmental Data Analysis (CEDA).