This dataset is a 90 meter resolution global river floodplain landform map based on terrain analysis. This method takes MERIT Hydro as the terrain input and Floodplain Hydraulic Geometry (FHG) as the threshold scheme, using a stepwise framework that respects both power law and approximate hydrodynamic modeling spatial range to estimate scale parameters. SHIFT effectively captures the global pattern of flood plains with better regional details than existing data.
This dataset provides data in two different resolutions to meet different needs.
SHIFT_v1_90m: Originating from the original SHIFT data of MERIT Hydro, lakes and reservoirs have not been removed yet. In the geographic coordinate system (EPSG: 4326), the resolution is 0.0008333333333 degrees, approximately 90 meters at the equator. A pixel with a value of 1 is a floodplain, 0 is a non floodplain, and a null value of 255 (indicating that pixels below the threshold are not within any watershed).
SHIFT_v1_1km: Resampled SHIFT data, marking lakes and reservoirs. In the geographic coordinate system (EPSG: 4326), the resolution is 0.008333333333333 degrees, approximately 1 kilometer at the equator. Pixels with a value of 1 are flood plains, 2 are lakes and reservoirs, 0 is non flood plains, and a null value of 255 (indicating that pixels below the threshold are not within any watershed).
MERIT Hydro's raw SHIFT data and resampled SHIFT data.
Specifically, we have developed a method for gradually estimating flood zone hydraulic geometry (FHG) scaling parameters for 269 watersheds worldwide, in order to best adhere to scaling rules while approximating the spatial range of two publicly available global flood maps derived from hydrodynamic modeling. Based on the FHG parameters of spatial variation, a global floodplain map with a resolution of about 90 meters was drawn, called "Improving Spatial Heterogeneity Floodplain through Terrain Analysis" (SHIFT). The map takes the hydrological corrected MERIT Hydro dataset as the DEM input and the height above the nearest drainage ditch (HAND) as the terrain attribute.
Our results indicate that the validation of SHIFT against the reference map is good, with an overall accuracy of over 0.85. Meanwhile, SHIFT has shown excellent consistency with several other independent hydrodynamic modeling and DEM based datasets. Compared with existing data, SHIFT can effectively capture global patterns of floodplain topography and provide better regional details. The estimated FHG index is significantly positively correlated with the climate and drought conditions in the watershed, especially in 34 major river basins around the world, indicating that scaling indices can capture more spatial heterogeneity.
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CSTR:11738.11.NCDC.ZENODO.DB6469.2024
10.5281/zenodo.10440609