Local and remote drivers of surface inundation and flood risk in the Mekong and Ganges River Deltas

Zachary Tessler, City College of New York, ztessler@ccny.cuny.edu (Presenter)
Kat Jensen, City College of New York, kjensen@ccny.cuny.edu
Charles Vorosmarty, City College of New York, cvorosmarty@ccny.cuny.edu
Kyle McDonald, The City College of New York, kmcdonald2@ccny.cuny.edu (Presenter)

Hydrologic changes in river delta systems occur over a broad

range of time scales, from hours (tides) to millennia (river bank

avulsion). Regular delta flooding supports sediment dispersal

processes and is important for the healthy functioning of many

natural ecosystems. At the same time, flooding in populated areas

can be catastrophic to communities and infrastructure. This

research investigates spatial and temporal surface inundation

response to local rainfall patterns, upstream hydrology, and

coastal storms in the Ganges-Brahmaputra and Mekong deltas.

Inferred inundation sensitivity maps are compared with land cover

and land use patterns, local rainfall, river discharge, and

offshore wave activity within and across the deltas. In the

Mekong, results indicate distinct areas of greater and weaker

surface water sensitivity to local rainfall. River discharge from

the upstream watershed is an important driver of local inundation

only in the upper delta, and coastal influence reaches

approximately 50km inland.

Another focus of this research is to develop a higher resolution

dataset that can leverage microwave remote sensing capabilities

and yet inform on surface inundation conditions at a scale more

appropriate for delta monitoring. The SWAMPS dataset is being

downscaled to a spatial resolution of ~100m. Topography from the

Shuttle Radar Topography Mission (SRTM) digital elevation model,

stream networks from Hydrosheds, and a permanent water cover mask

derived from Landsat are combined to compute a static, relative

flood-risk ranking representing the likelihood of flooding at

each grid point relative to those in the surrounding area. We

will present a test case in the Mekong delta region applying this

downscaling algorithm.

Presentation Type:  Poster

Session:  Theme 2: Landscapes to coasts: understanding Earth system connections   (Mon 1:30 PM)

Associated Project(s): 

• Vorosmarty, Charles: Global-Scale Assessment of Threatened River Delta Systems: Evaluation of Connections Between the Continental Land Mass and Ocean Through Integrated Remote Sensing and Process Modeling ...details

Poster Location ID: 136