Classification of water bodies at global scale by integration of satellite observation and geodatabases
Abstract
Recent progresses in remote-sensing techniques and big-data handling enabled the high-resolution mapping of inland waters at a global scale. Open surface waters can be detected by optical sensors (e.g. Landsat series) and had been mapped globally, and measurement of vegetates wetlands is achieved by passive/active microwaves. However, satellite-based mapping of inland waters only separates waters from lands; they do not tell the type of detected waters (i.e. rivers, lakes, reservoirs, and wetlands). As different types of water bodies play different roles in many hydrological and biogeochemical processes, classification of water bodies is required.
Here, we developed a first global "water classification" map at high-resolution (3 arcsec, 90m resolution), by combining Landsat-based surface water maps, global hydrography map, and several water body databases. First, open surface waters captured by global Landsat-based maps (G1WBM, Yamazaki et al. 2015; GSWO, Pekel et al. 2016) are carefully classified to permanent and temporal water bodies considering the connectivity of river channels. Second, Landsat-based river data GRWL (Allen & Pavelsky, 2018) was used to classify permanent waters to "RIVER", and then HydroLAKES (Messager et al. 2016) was used to classify residual permanent waters to classify "LAKES" and "RESERVOIRS". The remaining temporal waters are classified to "FLOODPLAINS". The preliminary result suggests that the derived "water classification map" covers most of the rivers and lakes/reservoirs on the earth, but we found small permanent water bodies which are not included in both GRWL and HydroLAKES remain "unclassified". Classification of these small water bodies is essential to complete the "water classification map", and also vegetated wetland should be added by integrating microwave-based water body products (e.g. GIEMS/GIEMS-3D; Prigent et al., 2007/Aires et al. 2018).- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H23C..08Y
- Keywords:
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- 1819 Geographic Information Systems (GIS);
- HYDROLOGYDE: 1855 Remote sensing;
- HYDROLOGYDE: 1856 River channels;
- HYDROLOGYDE: 1857 Reservoirs (surface);
- HYDROLOGY