Spatio-temporal analysis of flooding extent employing a MODIS vegetation proxy in the Sudd wetland of South Sudan
Presentation
Overview
Overview
Description
As one of the largest tropical wetlands in the world, the Sudd region of South Sudan supports not only one million people of transhumant pastoral cultures, but extremely high levels of biodiversity as well. Though the region is of documented international importance, there are plans to divert a percentage of the White Nile waters around the Sudd. The Jonglei Canal, the building of which was initiated in 1980 but halted in 1983 due to civil war, would reduce evaporative losses in the wetlands and provide more water to downstream users. However, documentation of the spatial hydrological and ecological interactions of the Sudd is still lacking, meaning that changes due the canal's completion cannot be predicted with high confidence. This study aims to partially fill this void by examining changes in intra- and inter-annual flooding extent from 2000 to 2014 in conjunction with variations in Lake Victoria water levels. As cloud cover often prohibits unblemished coverage of the area in the wet season, flooding extent was derived using the MODIS NDVI product as a proxy for the wetland area. These extents were found to be highly correlated with the flood area derived in the dry season using MODIS Land-surface temperature differencing methods. Though the general trends seen in lake levels have been reflected in the flood extent overall, the extreme decline in lake levels from 2004 to 2006 was not reflected in the extent changes of the Sudd, suggesting a more complex hydrological control in those years of low inflow.
