The Congo Basin is the world's third largest in size (~3.7millionkm2), and second only to the Amazon River in discharge (~40,200m3s-1 annual average). However, the hydrological dynamics of seasonally flooded wetlands and floodplains remains poorly quantified. Here, we separate the Congo wetland into four 3°×3° regions, and use remote sensing measurements (i.e., GRACE, satellite radar altimeter, GPCP, JERS-1, SRTM, and MODIS) to estimate the amounts of water filling and draining from the Congo wetland, and to determine the source of the water. We find that the amount of water annually filling and draining the Congo wetlands is 111km3, which is about one-third the size of the water volumes found on the mainstem Amazon floodplain. Based on amplitude comparisons among the water volume changes and timing comparisons among their fluxes, we conclude that the local upland runoff is the main source of the Congo wetland water, not the fluvial process of river-floodplain water exchange as in the Amazon. Our hydraulic analysis using altimeter measurements also supports our conclusion by demonstrating that water surface elevations in the wetlands are consistently higher than the adjacent river water levels. Our research highlights differences in the hydrology and hydrodynamics between the Congo wetland and the mainstem Amazon floodplain.
|Number of pages||9|
|Journal||Remote Sensing of Environment|
|Publication status||Published - 2011 Dec 15|
Bibliographical noteFunding Information:
This research is funded by NASA's Terrestrial Hydrology Program and by Ohio State University's Climate, Water and Carbon Program. We thank 3 anonymous reviewers for providing constructive comments. Some of the figures are prepared using the GMT graphics package (Wessel and Smith, EOS, 1991).
All Science Journal Classification (ASJC) codes
- Soil Science
- Computers in Earth Sciences