Department of Nexus-Based Risk Management

• Terrain Surface height in whole metres on a grid of 150 by 150 cells of about 1.8 kilometres; the basin floor lies under 100 metres and the ranges at the edges reach 1,700 metres. Produced using Copernicus WorldDEM-30 © DLR e.V. 2010–2014 and © Airbus Defence and Space GmbH 2014–2018 provided under COPERNICUS by the European Union and ESA; all rights reserved. read 2026-10-17. Estimate: A digital surface model: trees and roofs are in the heights. Relief exaggeration is printed on the stage.
• Named rivers The Mekong, the Tonle Sap river and the named tributaries as centrelines, with their length in kilometres. © beşdarên OpenStreetMap, ODbL 1.0. data as of 2026-07-15. Estimate: Centrelines as mapped, clipped to the box and simplified to 200 metres; no discharge or width is implied by the line.
• Dams One point for each mapped dam, with its name and operator where tagged. © OpenStreetMap contributors, ODbL 1.0. data as of 2026-07-15. Estimate: Mapped dams only; a missing dam means it is not mapped, not that it does not exist.
• Power plants The hydropower, oil, waste and biomass plants inside the box with their capacity in MW and primary fuel, the energy node of the loop. Power plants: Global Power Plant Database v1.3.0 (2021), World Resources Institute and partners, CC BY 4.0. release 1.3.0, 2021-06-02. Estimate: A 2021 snapshot, never current operating status.
• Cropland, tree cover, water and built-up shares (ESA WorldCover 2021) The share of cropland, tree cover, permanent water and built-up land in each of 200 by 200 cells, summarised at build time from the 10 metre product; the food and ecosystem nodes of the loop. (c) ESA WorldCover project 2021 / Contains modified Copernicus Sentinel data 2021 processed by ESA WorldCover consortium (CC BY 4.0); dataset: Zanaga, D. et al. (2022), ESA WorldCover 10 m 2021 v200, doi:10.5281/zenodo.7254221. read 2026-10-17. Estimate: A 2021 classification at 10 metres summarised to cells of about 1.4 kilometres from 16 sub-samples; not a crop yield, a harvest area or a wetland inventory.
• River discharge, GloFAS via Open-Meteo Daily Mekong discharge at the Kratie cell with the member range for the next 30 days, and on click anywhere in the box; the water inflow of the loop. Weather data by Open-Meteo.com (CC BY 4.0); river discharge: contains modified Copernicus Emergency Management Service information 2026 (GloFAS); never a flood warning. Live: this page requests flood-api.open-meteo.com when the layer is opened; the data date is printed with it. Estimate: Model output (forecast or reanalysis), shown with the member range where the API gives one; never a warning. The loop simulator adds one request to the same endpoint with start_date=1984-01-01 and end_date=today for the chosen cell to build the seasonal pulse.
• Vegetation index, MODIS Terra NDVI 8-day Vegetation greenness across the basin; the season scrub steps the 8-day periods through the flood pulse. MODIS Terra NDVI 8-day, NASA LP DAAC / LANCE, via NASA GIBS, with the product date. Live: this page requests gibs.earthdata.nasa.gov when the layer is opened; the data date is printed with it. We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Estimate: An indicator of vegetation condition, never yield or production.
• Surface water extent, OPERA DSWx (HLS): the flood pulse Open and partial surface water on the date shown: the lake’s seasonal expansion and contraction. OPERA Dynamic Surface Water Extent from HLS, NASA JPL OPERA (contains modified Copernicus Sentinel data; USGS Landsat), via NASA GIBS, with the product date. Live: this page requests gibs.earthdata.nasa.gov when the layer is opened; the data date is printed with it. We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Estimate: A classification from optical imagery; clouds leave gaps in the wet season; never a flood warning.
• Land cover classes, MODIS IGBP (annual) The 500 metre annual land cover classes (croplands, wetlands, forests) for the newest year GIBS serves, draped on the terrain beside the WorldCover shares. MODIS land cover (MCD12Q1, IGBP classes), NASA LP DAAC, via NASA GIBS, with the product year. Live: this page requests gibs.earthdata.nasa.gov when the layer is opened; the data date is printed with it. We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Estimate: A classification, not a crop area statistic.

Why this place: One box of about 270 by 275 kilometres holds the Tonle Sap lake, whose flow reverses with the Mekong flood pulse each year, the Mekong main stem from Kratie to Phnom Penh, the rice plains that the pulse irrigates, the fisheries that feed the country, and the hydropower and thermal plants of the Global Power Plant Database, so the water-energy-food-ecosystems nexus can be taught where the couplings are strong and well documented. Data quality: Copernicus DEM GLO-30 covers the flat basin in nine tiles, the GloFAS cell at Kratie answered 15,416 cubic metres per second through Open-Meteo on 2026-10-17, ESA WorldCover gives cropland, tree cover and permanent water shares per cell and MODIS the annual land cover classes, and OpenStreetMap maps the dams and the named rivers. It connects to the Water-energy-food-ecosystems nexus, Nexus-Based Risk Management (NRM), Systemic, compound and cascading risk and Complex systems and systems modelling disciplines and to the water, energy and food nexus field maps of the ecosystem sites, which draw on the same rows.