Development of a global inundation map at high spatial resolution from topographic downscaling of coarse-scale remote sensing data
Creators
- 1. ETH Zurich
- 2. McGill University
- 3. IWMI
- 4. IRD-LEGOS
- 5. Michigan State University
Description
Overview: The Global Inundation Extent from Multi-Satellites (GIEMS; Prigent et al. 2007, Papa et al. 2010) downscaled at 15 arc-second (GIEMS-D15; Fluet-Chouinard et al. 2015) was produced through the downscaling of the GIEMS database (natively at 0.25°). The downscaling procedure predicts the location of surface water cover with an inundation ranking surface generated by bagged decision trees. The decision trees were trained on binary presence/absence of wetland in the GLC2000 global land cover map (Bartholomé & Belward 2005) and used 13 topographic and hydrographic predictors derived from the SRTM-derived HydroSHEDS database (Lehner, Verdin & Jarvis 2008). The downscaling technique to three temporal aggregation of the GIEMS dataset representing three states of land surface inundation extents: mean annual minimum (MAMin; total area, 6.5 × 106 km2), mean annual maximum (MAMax; 12.1 × 106 km2), and long-term maximum (LTMax; 17.3 × 106 km2). The area of MAMin and MAMax from GIEMS were supplemented with the minimum area value from lakes, river and reservoirs from GLWD (Lehner & Döll 2004; classes 1,2,3). LTMax was corrected as the mean area from 3-year rolling maximum from GIEMS and the total wetland area from GLWD (classes 1-12). The accuracy of GIEMS-D15 reflects distribution errors introduced by the downscaling process as well as errors from the original satellite estimates. Yet, a comparison against independent regional wetland maps showed adequate agreement over large floodplains and wetlands. GIEMS-D15 offers a higher resolution delineation of inundated areas than originally offered by GIEMS, allowing for the assessment of global freshwater resources and the study of large floodplain and wetland ecosystems.
Projection: WGS84 (EPSG:4326)
Geographic extent:
- Longitude: -180° to 180°
- Latitude: -56° to 84°
Spatial resolution: 15 arc-second (500m at equator)
Legend (for discrete pixel values):
- 0 = Upland
- 1 = Mean Annual Minimum (MAMin)
- 2 = Mean Annual Maximum (MAMax)
- 3 = Long Term Maximum (LTMax)
Notes
Files
giemsd15.zip
Files
(64.0 MB)
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Additional details
References
- Bartholomé, E., & Belward, A.S. (2005). GLC2000: A new approach to global land cover mapping from earth observation data. International Journal of Remote Sensing, 26(9), 1959–1977.
- Fluet-Chouinard, E., Lehner, B., Rebelo, L. M., Papa, F., & Hamilton, S. K. (2015). Development of a global inundation map at high spatial resolution from topographic downscaling of coarse-scale remote sensing data. Remote Sensing of Environment, 158, 348-361.
- Lehner, B., & Döll, P. (2004). Development and validation of a global database of lakes, reservoirs and wetlands. Journal of Hydrology, 296(1–4), 1–22.
- Lehner, B., Verdin, K., & Jarvis, A. (2008). New global hydrography derived from spaceborne elevation data. EOS, 89(10), 93–94
- Papa, F., Prigent, C., Aires, F., Jimenez, C., Rossow, W.B., & Matthews, E. (2010). Interannual variability of surface water extent at the global scale, 1993–2004. Journal of Geophysical Research, 115(D12111), 1–17.
- Prigent, C., Papa, F., Aires, F., Rossow, W.B., & Matthews, E. (2007). Global inundation dynamics inferred from multiple satellite observations, 1993–2000. Journal of Geophysical Research, 112(D12107), 1–13.